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THE TEXAS JOURNAL OF SCIENCE
A Quarterly Review of Science
T. N. Campbell, Editor
CLAUDE C. ALBRITTON, JR., JOHN W. FORSYTH, GUY T. McBRIDE, JR. and JOHN G. SINCLAIR, Associate Editors
Printed in
San Marcos, Texas, U. S. A.
Published by
THE TEXAS ACADEMY OF SCIENCE
19 5 4
The Texas J ournal of Science Index To Vol ume VI
A
A Basic System of Grading in Physical Education Activity Courses, by Eldon D. Brinley, 271.
ABRAMSON, H. NORMAN, On the Representation of a General Force by a Step Function, 390.
A Comparative Study of the Respiration of Normal and Rumor Strains of Drosophila melanogaster, by Domenic A. Vavala, 194; ibid., II. Further Statistical Fvaluati ons, 450.
ACOSTA, LA RUE, Comparison of Two Procedures for Testing the Antibiotic Sensitivity of Micro-organisms, 340.
ADAMSON, CLAUDE L., Handedness: Result of Hereditary and Environmental Factors in Cerebral Dominance, 211.
ALEXANDER, F. A. DUNCAN and LOUIS W. LEWIS, The Management of Chronic Pain: A Factor in Human Conservation, 165.
ANDREWS, JAY D. and WILLIS G. HEW ATT, Oyster Mortality Studies in Virginia. I. Mortalities of Oysters in Trays at Gloucester Point, York River, 121.
Antibiotic sensitivity, procedures for testing, 340.
A Report on the Professional Status of Texas High School Science Teachers, by Robert C. Sherman and Oren C. Whitehead, 169.
A Revision of the Toads of the Bufo debilis Complex, by Jay M. Savage, 83.
Armadillo, distribution in the United States, 142.
A Study of Factors Influencing the Oil Content of the Seeds of Toria (Brassica compestris, L. var. Toria D & F), by Sultan Ahmad Tremazi, 217.
B
BARTON, SAM B., Higher Education in Texas: Coordination for What? 151.
Basic Medical Science in the Programs of the Texas Academy of Science, by John G. Sinclair, 345.
BLAIR, W. FRANK, Tests for Discrimination between Four Subspecies of Deer-mice (Peromyscus maniculatus), 201; Mammals of the Mesquite Plains Biotic District in Texas and Oklahoma, and Speciation in the Central Grasslands, 235; and DAVID PETTUS, The Mating Call and Its Significance in the Colorado River Toad (Bufo alvarius Girard), 72.
BRINLEY, ELDON D., A Basic System of Grading in Physical Education Activity Courses, 271.
BUCHANAN, G. D., and ROY V. TALMAGE, The Geographical Distribution of the Armadillo in the United States, 142.
c
CAMPBELL, T. N., and C. D. ORCHARD, Evidences of Early Man in the Vicinity of San Antonio, Texas, 454.
Ceremonies of the Coahuiltecan Indians of Southern Texas and Northeastern Mexico, by Frederick Ruecking, Jr., 330.
CHANEY, ALLAN H., and ROBERT E. GORDON, Notes on a Population of Sceloporus merriami merriami Stejneger, 78.
Commitments of the mentally ill in Texas, 26.
Comparative Notes on Southwestern Indian Medical Practices, by Charles H. Lange, 62.
473
474
The Texas Journal of Science
1954, No. 4 December
Comparison of Two Procedures for Testing the Antibiotic Sensitivity of Micro-organ¬ isms, by La Rue Acosta, 340.
Cooling and heating, economics of, in hot climates, 159.
Corrected Distributional Records for Texas Fresh-water Fishes, by Clark Hubbs, 277.
D
Dental status of children, factors affecting, 400.
Deer-hunting practices, Laguna Pueblo, New Mexico, 407.
Deer-mice, tests for discrimination between subspecies, 201.
DIETRICH, J. W., and I. I. PETERS, Electron Microscopic Observations on Rennet Action upon Skim Milk, 442.
DORAN, EDWIN, JR., Land Forms of Grand Cayman Island, British West Indies, 360.
Drosophila melanogaster, tumor strains of, 194, 450.
E
Early man in Texas, near San Antonio, 454.
Education, higher, in Texas, 151; status of Texas high school science teachers, 169; system of grading in physical education activity courses, 271.
Electron Microscopic Observations on Rennet Action upon Skim Milk, by I. I. Peters and J. W. Dietrich, 442.
Evidences of Early Man from the Vicinity of San Antonio, Texas, by C. D. Orchard and T. N. Campbell, 454.
F
FIREY, WALTER, JR., The Ecological Delination of a Planning Area, 189.
First Record of the Cypress Minnow ( Hybognathus hayi Jordan ) in Texas, by Robert J. Kemp, Jr., and Clark Hubbs, 113.
Fishes, Genus Paraclinus, 422; cypress minnow ( Hybognathus hayi Jordan), 113; corrected distributional records for Texas fresh-water fishes, 277.
Food Competition among Four Sympatric Species of Garter Snakes, Genus Tham- nophis, by M. J. Fouquette, Jr., 172.
FOUQUETTE, M. J., JR., Food Competition in Four Sympatric Species of Garter Snakes, Genus Thamnophis, 172.
FRIEDSAM, H. J., C. D. WHATLEY, JR., and A. G. RHODES, Some Selected Aspects of Judicial Commitments of the Mentally III in Texas, 26.
Frog, green (Rana clamitans Latreille), 1.
Fuels — Present Status and Future Prospect, by D. Ralph Lee, 353.
G
Geographic Variation in the Green Frog, Rana clamitans Latreille, by John S. Mecham, 1.
GOLDFRANK, ESTHER S., Notes on Deer-hunting Practices at Laguna Pueblo, New Mexico, 4 07.
Gopher, pocket (Geomys personatus), in southern Texas, 297.
GORDON, ROBERT E., and ALLAN H. CHANEY, Notes on a Population of Scelopurus merriami m-erriami Stejneger, 78.
Grand Cayman Island, British West Indies, land forms, 360.
Gulf of Mexico, origin of, 134.
H
Handedness and the Corpus Striatum, by John G. Sinclair and Nick Hightower, 215.
Handedness: Result of Heredity and Environmental Factors in Cerebral Dominance, by Claude L. Adamson, 211.
1954, No. 4 December
The Texas Journal of Science
475
HEW ATT, WILLIS G„ and JAY D. ANDREWS, Oyster Mortality Studies in Virginia, I. Mortalities of Oysters in Trays at Gloucester Point, York River, 121.
Higher Education in Texas: Coordination for What? by Sam B. Barton, 151.
HIGHTOWER, NICK, and JOHN G. SINCLAIR, Handedness and the Corpus Striatum, 215.
HORTON, C. W., and R. B. WATSON, On the Back-scattering of Radar Waves from the Trailing Edge of an Aircraft Wing, 392.
HUBBS, CLARK, Corrected Distributional Records for Texas Fresh-water Fishes, 277 ; and ROBERT J. KEMP, JR., First Record of the Cypress Minnow (Hybog- nathus hayi Jordan ) in Texas, 113.
I
Indians, of the Southwest, medical practices, 62; Coahuiltecan Indian ceremonies, 330; deer-hunting practices at Laguna Pueblo, New Mexico, 407.
Isolating Mechanisms in Sympatric Populations of Southwestern Anurans, by Charles H. Lowe, Jr., 265.
K
KAHAN, ARCHIE M., The First Texas Tornado Warning Conference, 156.
KEMP, ROBERT J., JR., and CLARK HUBBS, First Record of the Cypress Minnow (Hybognathus hayi Jordan ) in Texas, 113.
KENNERLEY, THOMAS E., JR., Local Differentiation in the Pocket Gopher ( Geomys personatus ) in Southern Texas, 297 .
KRUSE, OLAN E., Spectrum Analysis of Variable Slope Pulse Modulation Waves, 378
L
Land Forms of Grand Cayman Island, British West Indies, by Edwin Doran, Jr., 360.
LANGE, CHARLES H., Comparative Notes on Southwestern Indian Medical Prac¬ tices, 62; The Analysis and Application of Cultural Dynamics, 292.
LEE, D. RALPH, Fuels — Present Status and Future Prospect, 353.
LEWIS, LOUIS W., and F. A. DUNCAN ALEXANDER, The Management of Chronic Pain: A Factor in Human Conservation, 165.
Lizard, Merriam’s canyon (Sceloporus merriami merriami Stejneger), 78.
Local Differentiation in the Pocket Gopher ( Geomys personatus ) in Southern Texas, by Thomas E. Kennedy, Jr., 297.
LOWE, CHARLES H., JR., Isolating Mechanisms in Sympatric Populations of South¬ western Anurans, 265.
LYNCH, S. A., Resume of Thought Concerning Origin of Gulf of Mexico, 13 4.
M
Mammals of the Mesquite Plains Biotic District in Texas and Oklahoma, and Specia- tion in the Central Grasslands, by W. Frank Blair, 235.
Mammals, Big Bend region of Texas, 33; of Mesquite Plains Biotic District in Texas and Oklahoma, 235.
MECHAM, JOHN S., Geographic Variation in the Green Frog, Rana clamitans Latreille, 1 .
Medical practices of Southwestern Indians, 62.
N
Notes on a Population of Sceloporus merriami merriami Stejneger, by Allan H. Chaney and Robert E. Gordon, 78.
Notes on Deer-hunting Practices at Laguna Pueblo, New Mexico, by Esther S. Gold- frank, 407.
476
The Texas Journal of Science
1954, No. 4 December
0
On the Back-scattering of Radar Waves from the Trailing Edge of an Aircraft Wing, by C. W. Horton and R. B. Watson, 392.
On the Representation of a General Disturbing Force by a Step Function, by H. Norman Abramson, 390.
ORCHARD, C. D., and T. N. CAMPBELL, Evidences of Early Man from the Vicinity of San Antonio, Texas, 454.
Oyster Mortality Studies in Virginia. I. Mortalities of Oysters in Trays at Gloucester Point, York River, by Willis G. Hewatt and Jay D. Andrews, 121.
P
Pain, chronic, management of, 165.
PETERS, I. I., and J. W. DIETRICH, Electron Microscopic Observations on Rennet Action upon Skim Milk, 44 2.
PETTUS, DAVID, and W. FRANK BLAIR, The Mating Call and Its Significance in the Colorado River Toad (Bufo alvarius Girard), 72.
Planning area, ecological delineation of, 189.
R
Radar waves, back-scattering from the trailing edge of an aircraft wing, 392.
Rennet action upon skim milk, electron microscopic observations of, 442.
Resume of Thought Concerning Origin of Gulf of Mexico, by S. A. Lynch, 134.
RHODES, A. G., H. J. FRIEDSAM, and C. D. WHATLEY, JR., Some Selected Aspects of Judicial Commitments of the Mentally III in Texas, 26.
RUECKING, FREDERICK, JR., Ceremonies of the Coahuiltecan Indians of Southern Texas and Northeastern Mexico, 330.
s
SAVAGE, JAY M., A Revision of the Toads of the Bufo debilis Complex, 83-
Science Activities in Texas, 115, 225, 347, 466.
SHERMAN, ROBERT C., and OREN C. WHITEHEAD, A Report on the Professional Status of Texas High School Science Teachers, 1 69.
SINCLAIR, JOHN G., Basic Medical Science in the Programs of the Texas Academy of Science, 345; and NICK HIGHTOWER, Handedness and the Corpus Striatum, 215.
Slope pulse modulation waves, 378.
SMITH, EUCLID, Some Factors Affecting the Dental Status of Ten and Eleven-year Old Children, 400.
Snakes, garter, Genus Thamnophis, food competition, 172.
Some Factors Affecting the Dental Status of Ten- and Eleven-year Old Children, by Euclid Smith, 400.
Some Selected Aspects of Judicial Commitments of the Mentally 111 in Texas, by H. J. Friedsam, C. D. Whatley, Jr., and A. G. Rhodes, 26.
Spectrum Analysis of Variable Slope Pulse Modulation Waves, by Olan E. Kruse, 378.
SPRINGER, VICTOR G., Western Atlantic Fishes of the Genus Paraclinus, 422.
T
TALMAGE, ROY V. and G. D. BUCHANAN, The Geographical Distribution of the Armadillo in the United States, 142.
TAMSITT, J. R., The Mammals of Two Areas in the Big Bend Region of Trans- Pecos Texas, 33.
Tests for Discrimination between Four Subspecies of Deer-mice (Peromyscus mani- culatus ), by W. Frank Blair, 201.
1954, No. 4 December
The Texas Journal of Science
477
The Aanalysis and Application of Cultural Dynamics, by Charles H. Lange, 292.
The Ecological Delineation of a Planning Area, by Walter Firey, 189.
The Economics of Livability Cooling and Heating in Hot Climates, by W. R. Wool- rich, 159.
The First Texas Tornado Warning Conference, by Archie M. Kahan, 156.
The Geographical Distribution of the Armadillo in the United States, by G. D. Buchanan and Roy V. Talmage, 142.
The Mammals of Two Areas in the Big Bend Region of Trans-Pecos Texas, by J. R. Tamsitt, 33.
The Management of Chronic Pain: A Factor in Human Conservation, by Louis W. Lewis and F. A. Duncan Alexander, 165.
The Mating Call and Its Significance in the Colorado River Toad (Bufo alvarius Girard ), by W. Frank Blair and David Pettus, 72.
Toad, Colorado River ( Bufo alvarius Girard), 72; Bubo debilis Complex, revision of, 83; Southwestern anurans, isolating mechanisms in, 265.
Toria, oil content of seeds ( Brassica compestris) , 217.
Tornado, first tornado warning conference in Texas, 156.
TREMAZI, SULTAN AHMAD, A Study of Factors Influencing the Oil Content of the Seeds of Toria (Brassica compestris. L. var. D & F), 217.
V
VAVALA, DOMENIC A., A Comparative Study of the Respiration of Normal and Tumor Strains of Drosophila melanogaster, 194; ibid., II. Further Statistical Evaluations, 450.
w
Western Atlantic Fishes of the Genus Paraclinus, by Victor G. Springer, 422.
WHATLEY, C. D. JR., H. J. FRIEDSAM, and A. G. RHODES, Some Selected Aspects of Judicial Commitments of the Mentally III in Texas, 26.
WHITEHEAD, OREN C, and ROBERT C. SHERMAN, A Report on the Status of Texas High School Science Teachers, 169.
WOOLRICH, W. R., The Economics of Livability Cooling and Heating in Hot Climates, 159.
The Texas Journal of Science
Decemlier 1954, No, 4
Professional Directory
J. BRIAN EBY
Consulting Geologist 347 Esperson Bldg.
Ph. CH-4776 Houston, Tex.
LEONARD J. NEUMAN
Registered Professional Engineer
Geological and Geophysical Surveys Petroleum Engineering Reports Houston, Texas
Geophysics Office Engineering Office
943 Mellie Esperson Bldg. Ph. ’’reston 2705 Ph. FA-7086
LEO HORVITZ
Geochemical Prospecting Horvitz Research Laboratories Houston, Texas
Ph. KE-5545 3217 Milam Street
MICHEL T. HALBOUTY
Consulting
Geologist and Petroleum Engineer Shell Building
Houston 2, Texas Phone PR-6376
D’ARCY M. CASHIN
Geologist Engineer
Specialist Gulf Coast Salt Domes Examinations, Reports, Appraisals Estimates of Reserves
2018 Nat’l. Standard Bldg. Houston 2, Texas
WILLIAM H. SPICE, JR.
Consulting Geologist 2101-03 Alamo National Building SAN ANTONIO 5. TEXAS
HERSHAL C. FERGUSON
Consulting Geologist and Paleontologist Esperson Building HOUSTON, TEXAS
825% Gravier Street New Orleans, La.
PETTY GEOPHYSICAL ENGINEERING COMPANY
Seismic Gravity Magnetic Surveys 317 Sixth St. San Antonio, Texas
ZINGERY BLUE PRINT CO.
(“Greater Distance - Greater Discount”)
Phone Atwood 6483 435 Esperson Building Houston 2, Texas
E. E. ROSAIRE
Prospecting for Petroleum DALLAS, TEXAS
H. KLAUS
Geologist
KLAUS EXPLORATION COMPANY Lubbock, Texas
Consulting Geologists Appraisals Reservoir Engineers
DeGOLYER and MacNAUGHTON
Continental Building DALLAS. TEXAS
SAMPLE AND CHILDERS
C. H. Sample A. F. Childers, Jr.
Consulting Geologists 901 Southern Standard Bldg. Houston 2, Texas
JOHN L. BIBLE
Tidelands Exploration Co.
Seismic & Gravity Surveys on land and sea
2626 Westheimer Houston, Texas
1954, No. 4 December
The Texas Journal of Science
|
Professional Directory Continued |
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S. RUSSELL (PAT) CASEY, JR. Petroleum Management Company Electric Building Phone CH-1622 Houston, Texas |
LOCKWOOD & ANDREWS Consulting Engineers Houston 1 |
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DALE SHEPHERD, C. L. U. and Associates Estate Analysis - Pension Planning Insurance Programming - Business Insur. General Agents Connecticut Mutual Life Insurance Co. 1802-3-4-5 Esperson Bldg. Houston |
GEOCHEMICAL SURVEYS
3806 Cedar Springs Rd.
Dallas 4, Texas
&
318 F&M Bank Bldg. Abilene, Texas
1954, No. 4 December
The Texas Journal of Science
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EXECUTIVE COUNCIL, 1954
President: Joseph P. Harris, Jr., Southern Methodist University Executive Vice President: D. F. Leipper, The A. & M. College of Texas Secretary -Treasurer: Gladys H. Baird, Huntsville
Representative to the A. A. A. S.: Wayne Taylor, Denton High School Vice President, Sec. I, Physical Sciences: H. M. Moseley, Texas Christian University Vive President, Sec. II, Biological Sciences: Cornelia Smith, Baylor University Vice President, Sec. Ill, Social Sciences: J. L. Clark, Sam Houston State Teachers College
Vice President, Sec. IV, Earth Sciences: Leo Hendricks, Texas Christian University Vice President, Sec. V, Conservation: John C. Finerty, The University of Texas, Medical Branch
Collegiate Academy: Sister Joseph Marie Armer, Incarnate Word College Junior Academy: Greta Oppe, Ball High School, Galveston
BOARD OF DIRECTORS
President: Joseph P. Harris, Jr., Southern Methodist University Executive Vice President: D. F. Leipper, The A. & M. College of Texas Secretary-Treasurer: Gladys H. Baird, Huntsville
Immediate Past President: D. Bailey Calvin, The University of Texas, Medical Branch Elected Director: John J. Andujar, Fort Worth Medical Laboratory Elected Director: W. R. Woolrich, The University of Texas Elected Director: C. C. Doak, The A. & M. College of Texas
BOARD OF DEVELOPMENT
W. R. Woolrich, The University of Texas
L. W. Blau, Humble Oil & Refining Company, Houston
Everette DeGolyer, DeGolyer and McNaughton, Dallas
J. Brian Eby, Consulting Geologist, Houston
O. S. Petty, Petty Geophysical Company, San Antonio
Allan Shivers, Governor of Texas
MEMBERSHIP COMMITTEE
Chairman: E. L. Miller, Stephen F. Austin State Teachers College CONSERVATION COUNCIL
President: John G. Sinclair, The University of Texas, Medical Branch
PURPOSE: To encourage and coordinate research in Texas by bringing scientific workers together and by publishing the results of their investigations ; to' advise individuals and the government on scientific matters ; to assemble and maintain library and museum facilities. ORGANIZATION : The activities of the Academy embrace all scientific fields. In the Senior Academy, there are five Sections: Physical, Biological, Social, and Geological Sciences, and Conservation. Regionally, the Senior Academy is divided into three branches : East Texas, South Texas and West Texas. The Collegiate Academy promotes the organization of science clubs in colleges and universities. The Junior Academy encourages scientific activities in secondary schools.
MEMBERSHIP : “Any person engaged in scientific work, or interested in the promotion of science” is eligible to membership.
PUBLICATIONS: The proceedings and Transactions of the Academy are incorporated in THE TEXAS JOURNAL OF SCIENCE, published quarterly.
DUES : Annual members, $5.00 per year. Life members, at least $100.00 in one payment.
Sustaining members, $10.00 per year. Patrons, at least $500.00 in one payment. Life members and patrons are exempt from dues, receive all publications, and participate as active members.
SUBSCRIPTION RATES: Members $5.00 per year (address Secretary-Treasurer Gladys H. Baird, Huntsville, Texas). Single copies $1.25 each (address The Editor, The Texas Journal of Science, Box 8012, University Station, Austin Texas).
Volume VI, No. 1, March, 1954 Published Quarterly at San Marcos, Texas
(Entered as Second Class Matter, at Postoffice, San Marcos, Texas, March 21, 1949
Tlie Texas ) ournal of Science
Published Quarterly by The Texas Academy of Science EDITOR
T. N. Campbell Department of Anthropology The University of Texas Austin, Texas
John W. Forsyth Department of Biology Texas Christian University Fort Worth, Texas
Claude C. Albritton, Jr. Department of Geology Southern Methodist University Dallas, Texas
ASSOCIATE EDITORS
Guy T. McBride, Jr. Department of Chemistry The Rice Institute Houston, Texas
John G. Sinclair Department of Anatomy The University of Texas Medical Branch Galveston, Texas
I
PUBLICATION BOARD
J. Brian Eby, Chairman _ Consulting Geologist, Houston
John J. Andujar _ Fort Worth Medical Laboratory
Anton Berkman _ Texas Western College
L. W. Blau _ Humble Oil & Refining Co., Houston
C. C. Doak _ The A. & M. College of Texas
John C. Godbey _ Southwestern University
Joseph P. Harris, Jr _ Southern Methodist University
W. G. Hewatt _ Texas Christian University
H. A. Hodges _ Pan American College
Clifford B. Jones _ Texas Technological College
Ernest L. Kurth _ Southland Paper Mills, Inc., Lufkin
John B. Loefer _ Southwest Foundation for Research and Education
E. L. Miller _ Stephen F. Austin State College
C. M. Pomerat _ The University of Texas, Medical Branch
E. E. Rosaire _ Consulting Geophysicist, Dallas
H. J. Sawin _ University of Houston
Aaron P. Seamster _ Del Mar College
C. M. Shigley - Dow Chemical Company, Freeport
Cornelia Smith _ Baylor University
Victor J. Smith - Sul Ross College
Otto O. Watts - Hardin-Simmons University
Arthur W. Young - Texas Technological College
ADVERTISING DIRECTOR
Robert Lee Miller & Associates 1951 Richmond Houston 6, Texas
Volume VI
No. 1
Cover Picture
*
This is the green frog, Rana clamitans , one of the wide-ranging frogs in North America. It is common in parts of eastern Texas, but it is infre¬ quently seen because of its retiring habits and predilection for situations pro¬ viding an abundance of concealing vegetation. Its presence, however, may be revealed by the call, which resembles the "bung” produced by the pluck¬ ing of an elastic cord stretched over an empty box. The common name is not too appropriate for Texas specimens, which are more often brown, rather than green. The cover specimen is a male from Newton County, Texas. Photo by John S. Mecham.
See Mecham’s "Geographic Variation in the Green Frog, Rana clamitans Latreille,” in this issue of the journal.
Tlie Texas Journal of Science
CONTENTS FOR MARCH, 1954
Geographic Variation in the Green Frog, Rana clamitans
Latreille. John S. Mecham _ 1
Some Selected Aspects of Judicial Commitments of the Mentally Ill in
Texas. H. J. Frieds am, C. D. Whatley, Jr., and A. G. Rhodes - 26
The Mammals of Two Areas in the Big Bend Region of Trans-Pecos
Texas. /. R. Tamsitt _ 33
Comparative Notes on Southwestern Medical Practices. Charles H. Lange _ 62
The Mating Call and Its Significance in the Colorado River Toad
( Bufo alvarius Girard). W. Frank Blair and David Pettus _ 72
Notes on a Population of Sceloporus merriami merriami Stejneger.
Allan H. Chaney and Robert E. Gordon _ 78
A Revision of the Toads of the Bufo debilis Complex. Jay M. Savage _ 83
First Record of the Cypress Minnow ( Hybognathus hayi Jordan) in
Texas. Robert J. Kemp, Jr., and Clark Hubbs _ 113
Science Activities in Texas
115
GEOGRAPHIC VARIATION IN THE GREEN FROG, RAN A CLAM1TANS LATREILLE*
JOHN S. MECHAM The University of Texas
INTRODUCTION
The green frog, Rana clamitans , is one of the most common and widely distributed amphibians in North America. It is, therefore, somewhat sur¬ prising that the fact has so long escaped the attention of specialists that this species is divisible into two distinct geographic races. The name "green frog” is a very inept one when applied to Rana clamitans in the south. The typical form is usually described as one of our largest frogs, a green species with a yellow throat in the male. However, the frog of the south is only of moderate size, is brown in color rather than green, and the yellow throat color of the male may be completely absent. Nor does the green frog of the most northern portion of the range conform to the textbook description.
The primary objective of this paper is a taxonomic one: to describe the geographic variation in this species and to define the geographic races in¬ volved. However, it is hoped that this study will have a broader application than a mere exercise in taxonomy. There has been little detailed work on geographic variation in wide ranging in North American frogs, but already interesting parallels in body proportions which change with latitude are coming to light. This study demonstrates more conclusively the existence of such variation.
ACKNOWLEDGMENTS
For the loan of preserved material I am indebted to the following individuals and to their respective institutions: Dr. Doris M. Cochran, United States National Museum; Mrs. Bessie Matalas Hecht, American Museum of Natural History; Dr. C. F. Walker and Mr. James A. Peters, Museum of Zoology, University of Michigan; Mr. Arthur Loveridge, Mu¬ seum of Comparative Zoology, Harvard College; Dr. Edward H. Taylor, University of Kansas; Mr. Robert L. Humphries, University of Georgia; Dr. W. B. Davis, Agricultural and Mechanical College of Texas; Mr. Wil¬ fred T. Neill, Ross Allen’s Reptile Institute; Dr. Fred R. Cagle, Tulane University; Mr. M. Graham Netting, Carnegie Museum; Mr. E. B. Logier, Royal Ontario Museum of Zoology; Dr. W. Frank Blair, University of Texas. Dr. James A. Oliver of the New York Zoological Society has kindly furnished me with living material from the state of New Jersey, and Mr. Philip W. Smith of the Illinois State Natural History Survey has sent me two live specimens from southern Illinois. I would like to thank Mr. Richard J. Baldaup of Texas A. and M. College for his consideration in giving up a similar study on the same species. I am especially indebted to Dr. Coleman J. Goin under whose direction this project was undertaken and who has contributed many helpful criticisms and suggestions.
*A thesis submitted to the graduate council of the University of Florida in partial fulfillment of the requirements for the degree of Master of Science.
1
2
The Texas Journal of Science
1954, No. 1 March
MATERIALS AND METHODS
In the course of this study some 3000 preserved Rana clamitans, ex¬ clusive of tadpoles, have been available to me for study. The collections represented are listed under the section on acknowledgments. For the lo¬ calities represented refer to Fig. 7. A few live frogs have been examined from the states of New Jersey, Ohio, Maryland, Tennessee, Kentucky, Vir¬ ginia, South Carolina, Mississippi, and Illinois, in addition to a large number of living Texas and Florida specimens.
From the standpoint of numbers of preserved specimens in collections, the green frog might appear to be a species admirably suited for study. It is probably safe to say that no other North American Ranid, with the pos¬ sible exceptions of Rana pipiens and Rana catesbeiana, is so plentifully rep¬ resented. Unfortunately, however, a large proportion of specimens, particu¬ larly in the older collections, have proved to be almost valueless. Characters such as nature of skin tuberculation and body proportions suffer to a greater or lesser extent depending upon the conditions of preservation and degree of distortion; and original color, which is of considerable importance as evidence of raciation in Amphibia, is impossible to detect regardless of the condition of the specimen. Furthermore, frogs do not possess the meristic characters which survive the rigors of time and poor preservation, and which are of such utility in other groups of cold blooded vertebraes. Never¬ theless, it has been necessary to base this study almost entirely on preserved material, as the fresh specimens available have been too few for any ex¬ haustive analysis.
It is often customary to list by museum numbers all specimens utilized in a taxonomic study. Such a procedure is advantageous in that the exact material which forms the basis for conclusions reached in the paper is given. However, a listing in this paper of all specimens examined, particu¬ larly with reference to any particular character, is out of the question be¬ cause of the very large amount of material. For this reason individual speci¬ mens have been cited only in specific instances.
Measurements. All body measurements were made by means of vernier calipers and were taken to the nearest tenth of a millimeter. Measurements were taken as follows:
A. Total length — from the tip of the snout to the most posterior pro¬ jection of the urostyle, care being taken that the back was straightened in order to obtain maximum length without applying undue pressure. I regard this as a more accurate measurement in the case of preserved ma¬ terial than snout-vent length, as the bony vertebral column is less subject to shrinkage.
B. Tibia length— from the heel to the pfoximal end of the tibia at the knee, the tibio-fibula being appressed against the femur and the foot being appressed against the tibia.
C. Head length — from the tip of the snout to the posterior angle of the lower jaw.
D. Tympanum diameter — taken from anterior to posterior, and in¬ cluding the ridge usually found on the circumference of the tympanum.
Body length was obtained by subtracting head length from total length. Femur length, foot length, and head width were also recorded at first, but these measurements subsequently proved to be so inaccurate in preserved material as to be useless.
1954, No. 1 March
The Green Frog
3
NOMENCLATORIAL HISTORY
The green frog was first described under the name of Rana clamitans in Sonnini and Latreille’s Natural History of Reptiles in 1802, on the basis of material sent by Bose from South Carolina, the type locality being Charleston. Daudin (1802), in his Natural History of Reptiles , gave him¬ self credit for the name in Latreille’s work, giving it as Rana clamata, a spelling which was commonly used up to about 1890, although Le Conte (18 5 5) proposed that clamator be substituted for clamata, stating that clamator was the name originally suggested by Bose. Rafinesque (1820) de¬ scribed a dark frog, undoubtedly a green frog, from Lake George and Lake Champlain as Ranaria melanota, and Le Conte in 182 5 proposed the name Rana fontinalis for the green frog of the "northern states.” Harlan, in the same year, introduced a new synonym when he described Rana flaviviridis as a new species of the "middle states,” the description being one of the best up to that time of Rana clamitans. Holbrook, in his North American Herpetology (1842), described a dark, supposedly new form under the name of Rana horiconensis; the type locality was Lake George, the same as that of Rafinesque’s melanota. Agassiz ( 1850) described another dark spotted frog from the Lake Superior region as Rana nigricans (misread by Le Conte in 18 5 5 as Rana nigrescens ) .
Rhodes (1895) advanced the idea that there were two races of green frog, a medium-sized green Carolinian form and a large dark Canadian form which he called respectively Rana clamitans clamitans and Rana clami¬ tans melanota; the nigricans of Agassiz and the horiconensis of Holbrook were relegated to the synonomy of the latter. However, Cope (1889) dis¬ carded the idea of a far northern form on the basis that the variation was not constant, citing a dark Louisiana specimen as an example, and subse¬ quent writers have been content to regard Rana clamitans as a monotypic species.
NATURE OF THE GEOGRAPHIC VARIATION
The fact that the green frog of the southern coastal plain shows a number of differences from the better known animal of the more northern portions of the country has been overlooked by the majority of workers. Holbrook (1842) seems to have recognized the distinctiveness of the south¬ ern form when he assigned the frog of "Carolina and Georgia” to Rana clamitans, describing it as slender, reddish brown above, darker behind, silvery white beneath, upper jaw green. The green frog of the northern and middle states he called Rana fontinalis Le Conte, and did not regard it as occurring south of Virginia (De Kay, 1842, p. 62). Among more recent writers, Wright (1932) called attention to the fact that in specimens from the Okefinokee Swamp region, both adult and transformation sizes are smaller; in addition the venter is not so immaculate, and the young are more spotted ventrally than in the north.
It soon became obvious in the course of this study that Rana clamitans undergoes a break in a number of characters in an area which roughly ap¬ proximates the line of demarcation (i.e., the fall line) between the coastal lowland and the interior upland of the southern states. The lowland form appears to exhibit little variation of consequence from east to west, and Texas and Florida specimens are similar in most respects. Material from the upland areas of Alabama, Georgia, and the Carolinas is very similar to that
4 The Texas Tournal of Science 1954> No- 1
PLATE I. 1-4, Rana clamitans clamitans; 5-8, Rana clamitans melanota. 1, female, 2, male, Alachua County, Florida; 3, female, 4, male, Newton County, Texas; 5, fe¬ male, Union County, Illinois; 6, male, Frederick County, Maryland; 7 and 8, males, Giles County, Virginia.
1954, No. 1 March
The Green Frog
5
which comes from any of the more northern states within the range of the species, with the possible exceptions of northern New York, portions of Vermont, Maine, and New Hampshire, and northern Michigan. The differences which crop up in specimens from the latter portion of the range have received some attention in the literature, and I have reserved discus¬ sion of them for a special section in this paper. The nature of the differences involved between the green frog of the southern uplands and the northern and middle states, and the frog of the southern coastal plain are discussed below.
Dorsal Spotting. One of the more outstanding characteristics of adult green frogs from the southern coastal plain is the absence of any sort of spotting between the dorsolateral folds. Dorsal spotting has not been found in any adult examined from the southern coastal plain. A tendency toward an indistinct marbling or mottling has been observed in a few Louisiana, Texas, and Florida specimens, but the condition is rare, and almost all specimens are a monochrome dorsally.
Northern specimens, on the other hand, usually show at least some dorsal spotting in the adults, although there is a great amount of individual variation in this respect. The spots may be numerous or few, large or very small, and there is often a tendency for them to be concentrated and larger toward the posterior portion of the back. Often they are very distinct and contrast boldly with the ground color; sometimes they are enlarged to form very striking irregular blotches. In some specimens the spotting is less distinctly delimited, or may be evident only as a weak to strong mot¬ tling. In a few specimens there may be no trace of spotting whatever.
In order to give an indication of the frequency of spotting in northern populations, the number of specimens which definitely show dorsal spotting in those series available at the time of writing from a number of northern states are listed in Table I. All specimens are over 45 mm. snout-urostyle length.
The separation has necessarily been somewhat arbitrary in some cases; some specimens are so dark that it is difficult to tell if spotting is present or not, and a heavy mottling may grade into a spotted condition. Never¬ theless the widespread and frequent occurrence of some sort of dorsal spot¬ ting in green frogs in the northern states is clearly indicated, and is in marked contrast to the dorsal monochrome of all adult southern coastal plain specimens examined. There seems to be some indication of a gradual
TABLE I
|
Number of |
% showing definite |
|
|
State |
speciments |
dorsal spotting |
|
Wisconsin Northern Michigan |
83 |
83.1 |
|
(northern peninsula) Southern Michigan |
44 |
90.9 |
|
(southern peninsula) |
195 |
87.2 |
|
Northern Illinois |
39 |
69.2 |
|
Indiana |
55 |
72.7 |
|
New York |
94 |
81.9 |
|
Massachusetts |
97 |
79.4 |
|
New Jersey Alabama, Georgia, and South |
51 |
62.7 |
|
Carolina, all above fall line |
23 |
39.1 |
6
The Texas Journal of Science
1954, No. 1 March
decrease in the percentage of spotted individuals as one progresses south, but whether an actual cline or merely a zone of intergradation is indicated by the low incidence of dorsal spotting in the Alabama, Georgia, and South Carolina samples from above the fall line is impossible to say without large series of specimens from intermediate areas.
Recently metamorphosed green frogs from any part of the range usu¬ ally show a number of small dark dorsal spots, but these juvenile spots are rapidly obscured and lost on the southern coastal plain. All of 20 newly metamorphosed young collected by the writer in Alachua County, Florida, for example, exhibited this character. The largest Florida specimen exam¬ ined which still carried spots measured 43.3 mm. snout-vent, and most specimens lose them at a much smaller size. For Texas material, 42.7 mm. was the largest size recorded for a specimen in which the juvenile dorsal spotting was still visible.
Skin Characters. I have been unable to devise a quantitative method for describing variation in skin characteristics. Differences are nonetheless apparent, and can be described in general terms.
Upon close examination any green frog will be seen to be covered on the back with very fine and small tuberculations or mammillations, the apices of which, under slight magnification, are visible as light points. His¬ tological examination revealed that these points are formed by the local¬ ized thickening or swelling of the more superficial layers of the epidermis. The corium is not involved, and there does not seem to be any relationship between this thickening and the glands of the stratum spongiosum.
In specimens from the southern coastal plain the surface of the back is relatively smooth and even except for these fine white tuberculations, and the general appearance might be compared to sandpaper. This condition holds true for all green frogs examined from the coastal lowlands from Texas to Florida. The only obvious exceptions encountered were two frogs from southeastern Louisiana (out of 81 adults from the state) .
In northern material, however, a rugose condition of the back is often encountered. This is caused by enlarged rounded elevations of the skin sur¬ face, each elevation usually centered under one of the above mentioned mammillations, but often carrying several. When these elevations are well developed, the back is quite rough and irregular in appearance. As the de¬ gree of rugosity is very variable, and may be weakly developed or absent, many northern individuals are indistinguishable from the southern frogs on this basis. However, a representative series from any area in the north usually reveals the presence of this condition.
The skin on the sides, below the dorsolateral folds, is a more reliable index than that on the back. The surface of the skin here is again covered with fine light points like those on the back. In the southern frog, these are superimposed upon a surface of rather sparsely scattered, wart-like, pointed elevations, one of the points always forming the apex of the ele¬ vation. Northern specimens usually differ in that there is an increase in the number of these elevations, which are in general lower, broader, more rounded, and not pointed. In some individuals, the elevations are so large and numerous that they juxtapose and the lines of contact between them are marked by creases or cracks, resulting, with corresponding flattening of the elevations, in an almost subreticulate creasing effect.
Ventral Marking . Ventral marking is extremely variable in the green frog, but some general statements concerning it may be made. Adult north-
1954, No. 1 March
The Green Frog
7
ern green frogs are immaculate beneath with the exceptions of the throat, lower lips, anterior pectoral region, and under surface of the hind legs, all of which may or may not carry some marking. Even when this marking is very dark, as it is on rare occasions, the belly is almost always immacu¬ late. In adults from the southeastern coastal plain (Georgia, Florida) the belly again is often plain, but in many specimens a dusky vermiculation is evident. In some cases, usually subadults, this belly marking may be dark to black. This condition has been noted by Wright (1932) in specimens from southeastern Georgia.
Ventral marking is much more vivid in very young than in older frogs, fading rapidly with age, although, as pointed out, adults may some¬ times be encountered in which the ventral markings are still dark and con¬ trasting. Examination of newly metamorphosed specimens therefore would be expected to reveal more conclusively if any significant geographic varia¬ tion in ventral marking exists. Such proves to be the case. All newly meta¬ morphosed or very young specimens examined from Florida and southern Georgia are very heavily marked on the venter and particularly on the belly. In the aforementioned series of twenty newly metamorphosed young collected by the writer in Alachua County, Florida, every specimen pos¬ sesses a heavy vermiculate spotting on the venter which varies in intensity from brown to black, and is particularly pronounced in the region of the belly. In northern green frogs at a comparable state of growth there may be considerable dark marking upon the venter, but it is usually thinner, is almost always limited to the lips, throat, pectoral region, and undersurface of the hind limbs, and is completely absent or very reduced in the region of the belly. There are rare exceptions to this statement, but in general it holds true in all the specimens available.
Ventral marking in the western part of the southern coastal plain appears to agree closely with that in the northern portions of the range. Belly marking in the younger specimens examined from Texas and Louisi¬ ana has been thin or absent, suggesting strongly that increase in ventral marking, particularly in the region of the belly, is restricted to the more eastern part of the southern coastal plain.
An exceptional instance of belly marking in more northern frogs was noted and should be mentioned. In a series of six specimens from Alex¬ ander County, Illinois (Chicago Natural Flistory Museum, 216 (2), 2161, 2173, 2206, 2208), five showed a strikingly heavy dusky to black mottling or vermiculation on the belly as well as the pectoral region and throat. Such marking must be a local condition, however, as specimens examined from nearby counties in Illinois and Missouri exhibit typically unmarked bellies.
Color. It may not be justifiable to place much emphasis upon geo¬ graphic variation in color in this paper as the live material necessary for a complete analysis has not been available. However, on the basis of the few live frogs examined it is possible to arrive at some tentative conclusions.
Color in the northern green frog is variable. Typically the adult animal is green to greenish brown above, sometimes tending toward olive posterior¬ ly. On rare occasions much darker individuals are encountered. The back is plain to spotted, with a bright green to yellow green mask extending for¬ ward from the tympanum along the jaw. The underparts are white with a varying amount of dark marking of varying intensity on the lower lip, pectoral region, sides, undersurface of the hind legs, and throat, the last
8
The Texas Journal of Science
1954, No. 1 March
more often being heavily marked in females (although males may often exhibit some degree of throat marking) . The throat in the sexually mature male is a brilliant yellow, with a yellow suffusion sometimes extending back over the pectoral region and up over the lips. The center of the tympanum in the male is a raised yellow to yellow green spot.
Detailed descriptions of northern frogs are unnecessary here, since Wright (1949), Breckenridge (1944), Dickerson (1906), and others give good descriptions of the green frog of the northern states, and together give a fairly complete picture of the range of variation involved.
As previously stated, the only live frogs obtained from the southern coastal plain have been from Florida, Mississippi, and Texas. With the ex¬ ception of one specimen, all were collected by the writer. Of the Florida frogs (roughly 230), all came from Alachua County with the exception of one adult from Jackson County. Two specimens were collected in Ffan- cock County, Mississippi. Texas specimens obtained were five subadults from Leon County, four adults and 30 juveniles from Nacogdoches County, one adult and two subadults from Shelby County, and eight adults from Newton County.
The Florida green frog is very rarely green at all. The adult animal is brown above, with or without the light green along the upper lips. The face is bronze, which merges into the brown of the back, and the brilliant green coloring of the head or anterior portion of the body which is so typical of specimens of more northern areas is not exhibited.
The following description is based on three adult females from Alachua County, Florida. The face is bronze, merging into an olive brown or brown upon the back, changing to lighter beneath the eye and beneath the ear¬ drum becoming a yellow gold stripe which extends onto the body above the leg. In one of the specimens this stripe is considerably darkened. The sides (below the dorsolateral ridge) are grayer and somewhat lighter. There is a narrow dark stripe above and behind the eardrum, following the ridge. The belly and underside of the hind legs are quite vermiculate in the dark¬ est of the three specimens, faintly in the other two. There is a dark spot in the center of the eardrum of all three. The underside of the throat is very faintly tinged with yellowish bronze.
With few limitations this description is typical for Florida specimens. The coloration of the male is very similiar to that of the female with the exception of a light spot in the center of the tympanum and sometimes more yellow on the throat. The yellow throat color is much reduced in comparison with northern males, however, and in many specimen? examined was completely absent.
The coloration of fresh Texas material agrees in most respects with that of the Florida specimens. In general, Texas frogs exhibit a brown rather than green dorsal coloration with a corresponding reduction of yellow throat pigment in the male. The description of four adults (three females and one male) collected in Nacogdoches County on November 9, 1952, are as follows. Three specimens are a light brown above, and fourth speci¬ men a darker brown, with a lighter, more bronze head. The lighter color of the head is intensified toward the margin of the upper lip, and forms a yellow-gold stripe below the tympanum, the stripe extending onto the body a very short distance above the foreleg. The sides are slightly lighter than the back, and become paler toward the belly. The venter is white, with a varying amount of dusky vermiculate marking upon the pectoral
1954, No. 1 March
The Green Frog
9
region, lateral margins of the belly, and femur. There is some marking upon the throat of two of the females, and the throat of the male is a light dusky hue without the faintest trace of yellow pigment.
Out of six adult males collected in Newton County, Texas, in April of 1952 and 1953, four had no yellow pigment whatsoever upon the throat, while the other two exhibited only a small bit of yellow on either side of this region. In addition I was able to examine a series of freshly pre¬ served specimens in the collection of the University of Texas. These frogs, included among which were 17 adult males, were collected in Newton and Harrison Counties, Texas, June 9-20, 1952, and were examined by the writer on July 19, 1952. None of the males exhibited any traces of yellow throat pigmentation, and it seems very unlikely that all the color would have been lost in so short a time.
A single male (approximately 50 mm. snout-vent) collected in Han¬ cock County, Mississippi, in April of 1952, possessed the brown dorsum of Texas and Florida material, and also lacked the yellow throat color. It might not be wise, however, to place too much reliance on the throat color of any but a fully adult specimen.
We can conclude with a fair degree of certainty that the absence or reduction of yellow throat color in adult males is characteristic of Texas as well as Florida males, and it seems very likely that material along the whole of the southern coastal plain forms a fairly homogeneous unit as far as coloration is concerned. Certainly Texas and Florida populations seem to agree closely in this respect; and although the evidence from intermedi¬ ate localities is incomplete, the preserved material is very similar in ap¬ pearance.
It would seem that frogs above the fall line in the states of Georgia, Alabama, and South Carolina, for the most part agree in color with those from farther north. An adult male and female collected by the writer in Jefferson and Sevier counties, Tennessee, respectively, certainly bear out this contention as they were typically northern in coloration and agreed very well with live material examined from Kentucky, Ohio, New Jersey, Maryland, and Virginia. An adult male collected in Fairfield County, South Carolina, was green with the yellow throat and immaculate white belly of the northern form.
Mr. Philip W. Smith has informed me that green frogs on the Mis¬ sissippi floodplain of Alexander and Union counties in Illinois are darker, and do not have the green jaw and yellow throat of northern and eastern males. This indicates that the coloration of the coastal plain race may extend as far up the valley of the Mississippi River as extreme southern Illinois. Hurter (1911) has remarked on the dark color of Rana clamitans collected in a cypress swamp in Dunklin County, Missouri.
The typical green of northern specimens presumably is due to the combination of yellow pigment with a structural blue. This simple ex¬ planation is strongly substantiated by the presence in the literature of de¬ scriptions of “blue” green frogs (Wright, 1949; Vogel, 1942). The blue color of these specimens can be explained very simply as being due to the absence of yellow pigment. In keeping with this explanation, it can be postulated that the brown color of the dorsum in southern coastal plain specimens is due to a general reduction in yellow pigment (possibly cor¬ related with some increase in melanins), and that this general reduction is reflected in an absence of yellow on the throat in adult males.
NUMBER OF SPECIMENS
10
The Texas Journal of Science
1954, No. 1 March
FIG. 1. Histograms are plotted showing the number of specimens in each sample which fall into the indicated size groups. The difference in maximum size between northern and southern material is clearly indicated.
It should be noted that Rana clamitans seems to be capable of at least a small degree of color change in life. Some coastal plain specimens have been observed to change from a very dark brown with very vivid ventral markings, to a relatively pale brown with almost indistinguishable ventral markings in a matter of minutes.
1954, No. 1 March
The Green Frog
11
Size. The Ran a clamitans of the southern coastal plain is a smaller animal than the form of the north. This is seen to be true if the accompany¬ ing histograms are inspected (Fig. 1). These include measurements of series available from the indicated states, the lower limit of 5 5 mm. being en¬ tirely arbitrary. By inspection it may be seen that the maximum size limits of the Texas, Florida, and Louisiana samples are comparable, as are those of New York, Indiana, and Michigan. When the respective northern and southern values are lumped and compared directly, the discrepancy between the two is very apparent. Only a very few of the southern specimens ex¬ amined exceeded 75 mm. snout-urostyle, while a goodly number of the northern ones exceeded 8 5 mm. This amounts to a difference in size ex¬ pressed as body length of roughly 1 5 % of the maximum size obtained by the species.
As would be expected, the tadpole also is smaller in the south than in the north. Table II is a comparison of total length in two series of rep¬ resentative larvae. The northern specimens are from Ocean County, New Jersey, while the southern material was collected in Alachua County, Florida. All of the specimens are at a comparable stage of development, having well developed hind limbs but not externally evident from front ones. Only perfect individuals with complete tails were selected.
TABLE II
Size of New Jersey and Florida larvae
|
Number of |
Mean total |
|||
|
specimens |
length (mm.) |
Range |
<r |
|
|
New Jersey |
14 |
64.3 ± .79 |
58.2-69.7 |
2.95 |
|
Florida |
10 |
57.4 ± .90 |
51.7-60.5 |
2.83 |
BODY PROPORTIONS
A number of statistically significant differences in body proportions can be demonstrated between green frogs from various parts of the range. These differences are of biological interest, but it is doubtful if any of them can be utilized as a key character because of the small magnitude of the dissimilarities and the wide range of individual variation (although variation would undoubtedly be reduced if fresh material were available) . A further complication here is the smaller size of southern coastal plains specimens. This difference in size tends to minimize differences in body pro¬ portions between northern and southern frogs when a comparison is made between specimens of the same body size.
All measurements have been expressed as ratios so as to emphasize differences in relative size rather than actual size. The ratios which have been found to be of value in this study are: (a) head length over body length, (b) tibia length over body length, (c) tympanum diameter over head length. A ratio which might well be of use with fresh material is head width over head length, but the results obtained with preserved ma¬ terial are too variable to form the basis for any definite conclusions.
Only frogs with a snout-urostyle length of 45 mm. or over were measured. The initial intention was to lump these specimens into one or a few size groups for statistical comparison. However, it was found that
BODY LENGTH IN MM.
12
The Texas Journal of Science
1954, No. 1 March
HEAD LENGTH/ BODY LENGTH
hi O)
FIG. 2. Best fit lines as calculated by the method of least squares are given for head length divided by body length plotted against body length for the indicated samples. One standard error of the estimate (narrow vertical line) and two standard errors of the mean of regression Y (heavy vertical line) are given on either side of the mean of Y.
1954, No. 1 March
The Green Frog
13
differences between the samples were of such a low level that they were completely obscured by ontogenetic changes where size groups big enough to include samples large enough for analysis were used. I have therefore interpreted the measurements for head length and tibia length in terms of rectilinear regression, a procedure which is permissible for a segment of the total growth line.
No indications of sexual dimorphism in the relative length of the tibia or head were found in either the northern or southern material. There is, of course, a marked dimorphism in tympanum size, and there is evidence of a relatively greater head width in the male, although the effect is greatly exaggerated by the presence of. prominent skin folds. The female attains a body length several millimeters in excess of the male.
Samples from northern Florida, southeastern Louisiana, Texas, New York, northern Indiana, and Michigan were selected for analysis. These are areas from which the best series of measurable frogs were available, and represent the eastern and western extremes of both the northern and south¬ ern portions of the range. No differences of any consequence could be dem¬ onstrated for body proportions between specimens from northern and south¬ ern peninsular Michigan, and the Michigan and northern Indiana samples agreed closely. All Michigan and northern Indiana material has therefore been lumped for the sake of simplicity. The Louisiana sample has been restricted to material from St. Charles, St. Landry, Jefferson, Assumption, Lafayette, Washington, St. Tammany, Orleans, and Iberia parishes, as ma¬ terial in the more northern and western portions of the state is closer to Texas material in body proportions. The number of specimens in each sample is as follows: Florida, 47; Louisiana, 39; Texas, 42; Michigan + Indiana, 89; New York, 61.
Head Lenth verms Body Length. The best fit lines for the indicated samples (body length 26-48 mm.) as calculated by the method of the least squares are given in Fig. 2 for head length divided by body length plotted against body length. The standard error of the estimate and the standard error of the mean of regression Y* have also been indicated graphically for each sample.
As can be seen by inspection, both the Texas and Florida lines fall well above that of the Louisiana sample; in other words, the head tends to be longer at a given body length in both Texas and Florida material. The Florida specimens seem to have slightly shorter heads than the Texas frogs, but the difference is not significant.
The fact that the Texas and southeastern Louisiana green frogs are different for head length is surprising in view of the fact that the states are adjacent and both are upon the southern coastal plain. However, this distinction is highly significant, as is shown by the scatter diagram, Fig. 3. A line plotted as the distance midway between the best fit lines of the two populations separates 66.7% of the Louisiana material from 76.2% of the Texas sample, a separation which approaches a level usually accepted as
* The standard error of the mean of regression Y ( = Sy/ VN ) can be used for an approximation of the significance of difference between the samples. This is done by moving the bars representing standard errors of the two samples to be compared toward each other along their respective regression lines to a position in the same vertical line. This seems to the writer to be justified where the slope of the lines is similar for different samples, and the loci of the means of Y are close together on the X axis.
14
The Texas Journal of Science
1954, No. 1 March
HEAD LENGTH/'-'BODY LENGTH
8 is $
FIG. 3. Ratios of head length divided by body length are plotted against body length for Texas (solid circles) and southeastern Louisiana specimens (hollow circles). A line plotted as the distance midway between best fit lines of the two samples sep¬ arates 76.2% of the Texas material from 66.7% of the Louisiana material.
sufficient for the recognition of subspecies. When tested in terms of chi square (adjusted formula) utilizing a fourfold table, this is found to be highly significant (x2 = 13.7, P less than .01).
The Michigan + Indiana and New York lines agree closely and fall well below those of the Texas and Florida samples for the greater part of their length. However, the slope for both of the northern samples is considerably less than that of the three coastal plain series, making it difficult to com¬ pare northern and southern material statistically, as the degree of diverg-
1954, No. 1 March
N333Q 3HJL
15
TIBIA LENGTH / BODY LENGTH
oo bo (s b
O 00 to
FIG. 4. Best fit lines as calculated by the method of least squares are given for tibia length divided by body length plotted against body length for the indicated samples. One standard error of the estimate (narrow vertical line) and two standard errors of the mean of regression Y (heavy vertical line) are given on either side of the mean of Y.
ence becomes much less at a larger body size (regression coefficients are: Florida, -.54; Louisiana, -.63; Texas, -.51; New York, -.3 3; Michigan + Indiana, —.40). The different slope can be explained as the result of a slower rate of increase in body length relative to head length in northern frogs
16
The Texas Journal of Science
1954, No. 1 March
TIBIA//BODY LENGTH
V| ® CD ® <0 <0 —
Oi O & CD to 0) O
FIG. 5. Ratios of tibia length divided by body length are plotted against body length for southeastern Louisiana (solid circles) and Florida specimens (hollow cir¬ cles). A line plotted as the distance midway between best fit lines of the two samples separates 69.2% of the Louisiana material from 61.7% of the Florida material.
as compared with southern frogs, or, as is more likely, as representing a different section of the growth line. The northern animal attains a larger maximum size, and specimens of the same body length as southern coastal plain specimens ‘probably represent an earlier stage of growth.
Tibia Length versus Body Length. The best fit lines for the same samples as given in Fig. 2 have been plotted in Fig. 4 for tibia length divided by body length plotted against body length. The standard error of the es¬ timate and the standard error of the mean of regression Y have been indi¬ cated graphically.
HEAD LENGTH IN MM.
1954, No. 1 March
The Green Frog
17
TYMPANUM/HEAD LENGTH
FIG. 6. Mean ratios of tympanum diameter divided by head length are plotted against head length for coasttal plain (Texas, Louisiana, Florida) and northern (New York, Michigan, Indiana) material. Specimens have been lumped into 2.5 mm. groups; the number of specimens determining each locus is given..
The variation in tibia length tends to be greater than in head length, particularly in the Florida sample. Louisiana and Texas populations agree closely, and both fall a significant distance below the Florida material, show¬ ing that the tibia is slightly longer proportionately in the latter. The
18
The Texas Journal of Science
1954, No. 1 March
Florida and Louisiana specimens have been plotted on the scatter diagram, Fig. 5, and a line of separation representing the distance midway between the best fit lines of the two samples has been drawn. This line separates 69.2% of the Louisiana material from 61.7% of the Florida material (x2 = 7.0, P less than 0.01), a separation which again approaches that of a magnitude large enough for subspecific recognition.
As in head length, the slope of the line for the Michigan + Indiana and Mew York samples is less than that of the coastal plain material, mak¬ ing direct comparison between northern and southern frogs difficult ..(re¬ gression coefficients are: Florida, -.60; Louisiana, -JO; Texas, -.58 ; New York, -.30; Michigan + Indiana, -.30). A small difference in tibia length between east and west in the north is indicated, but when placed on a scatter diagram only 5 5.7% of the Mew York frogs could be separated from 5 8.4% of the Michigan + Indiana specimens.
Tympanum Diameter versus Head Length. Adult green frogs may be assigned to the correct sex at a glance because of the strikingly larger tympanum of the male. However, sexual dimorphism in this structure be¬ comes evident only with age, and the sexes cannot be distinguished from each other on this basis during the early stages of growth.
In this connection it is interesting to note that sexual dimorphism in tympanum size becomes evident at a much smaller head length in southern specimens than in northern ones. This is obvious in the accompanying graph (Fig. 6) in which specimens have been lumped into northern and southern groups (done for the sake of convenience as the Texas, Florida, and Louisi¬ ana samples agr£e closely, as do those from Indiana, Michigan, and NetV York). Actually this is exactly what would be expected in view of the evidence previously presented which showed that the southern frog is a smaller animal than the northern one, and the appearance of the tym¬ panum dimorphism at a smaller head size (and therefore body size) in southern material simply confirms this fact.
The discrepancy between the two lines representing the ratios of tym¬ panum to head length in the males is so great in the lower size range that there is a possibility that the ratio may be used as a key value for the iden¬ tification of a population. For example, if males with a head length of 20.0-22.5 mm. are selected from the material used in the graph (13 coastal plain specimens, 20 northern), a tympanum to head length ratio of .32 5 separates 10 coastal plain specimens from 1 5 of the northern ones, or 77.0 and 75,0% respectively.
THE QUESTION OF NORTH TO SOUTH CLINES IN BODY PROPORTIONS
Schmidt (1938) has pointed out the possibility that a geographic gradient, somewhat analogous to the Bergman and Allen rules for warm blooded animals, exists in North American frogs for length of the hind leg relative to the body. According to- Schmidt, the relative length of the hind leg becomes progressively less with increase in latitude. Assuming tibia length to be an index of the total leg length, he presented evidence based on Rana sylvatica , Rana pipiens, Pseudacris nigrita , Hyla versicolor, and the Chinese species Rana nigromaculata , which indeed seems to support his contention that the tibia is proportionately smaller relative to body length in the more northern portions of the range. Unfortunately, however, the
1954, No. 1 March
The Green Frog
19
samples used are small, and no statistical evaluation is given. Moreover the size range among the specimens in some of the samples is so large that onto¬ genetic changes enter into the picture.
Moore (1944) has made a detailed study of the geographic variation in Rana pipiens, and Daugherty (unpublished thesis) has done work on the same animal. These two workers found that both the head and the tibia tend to be relatively longer in southern specimens of the species; data on Rana pipiens therefore substantiate Schmidt as far as the tibia is concerned. Smith and Smith (1952) have analyzed tibia length in two races of the chorus frog, Pseudacris nigrita. They found a relatively smaller tibia in triseriata, the more northern of the two races studied, although reduced tibia length was not indicated in the northern extension of the southern race, feriarum, east of the Appalachian Mountains.
Aside from these three papers, I know of no comprehensive study of a wide-ranging North American frog which includes an analysis of body proportions. In view of the scarcity of evidence in this matter, a com¬ parison of the results obtained in Rana clamitans with that which would be expected on the basis of Schmidt’s paper is of considerable interest.
At first glance the evidence in Rana clamitans would seem to be in¬ conclusive. This is because we are comparing northern and southern frogs of the same body length. Such a comparison is useful as far as determining whether a key character based on body proportions exists; it is fallaci¬ ous, however, from the biological standpoint, because the green frog is much smaller on the southern coastal plain than it is in the north. There¬ fore, although we are comparing frogs of the same body length, we are not comparing frogs of the same stage of growth.
The maximum size for northern and southern specimens respectively (Fig. 1), as well as the head size at which tympanum dimorphism be¬ comes evident (Fig. 6), indicate convincingly that the northern adult is at least ten mm. larger than the southern adult. If the lines on the graphs (Figs. 2 and 4) representing ratios of the coastal plain specimens are moved ten millimeters to the right so as to compensate for the size difference, it becomes apparent that both tibia and head length are longer relative to the body in all three samples from the coastal plain in comparison with the northern series. In other words, at the same stage of growth, southern green frogs tend to have a longer head and tibia relative to the body.
Viewed in this light, the data on body proportions in Rana clamitans supports the contention that tibia length (and consequently length of hind leg) in frogs tends to be proportionately shorter in the more north¬ ern portion of the range. Moreover the fact that the head length in both Rana pipiens and Rana clamitans is shorter relative to the body in northern specimens indicates that the shorter head is correlated with the shorter tibia.
VARIATION IN THE MOST NORTHERN PORTION OF THE RANGE
Many workers have remarked on the unusual appearance of green frogs in the most northern portion of the range. As pointed out in the nomenclatorial history, no less than three synonyms in the literature are based on material from northern areas. The name Ranaria melanota was proposed by Rafinesque (1820) for green frogs of the region of Lake Champlain and Lake George, New York. The description reads as follows: "Back olivaceous black, a yellow streak on the sides of the head; chin.
20
The Texas Journal of Science
1954, No. 1 March
throat and inside of legs whitish, with black spots; belly white without spots. — Vulgar name Black Frog.” Holbrook (1842) proposed the name Rana horiconensis for a dark, olive brown, spotted frog in the same region. Agassiz (1850) described his Rana nigricans of the Lake Superior region as "blackish brown or dark brown, more or less distinctly spotted with darker.”
Logier (1928) has remarked on the unusually dark coloration of green frogs from the Lake Nipigon region, Ontario, and Wright (1939) men¬ tions heavy spotting and dark color in Adirondack Mountains specimens. Fowler and Cole (1938) and Oliver and Bailey (1939) remark on the usu¬ ally heavy marking and darkening in frogs from Vermont and New Hampshire respectively. Trapido (1940) describes green frogs from north¬ ern Vermont which have black blotches and greenish black coloration simi¬ lar to that of Rana septentrionalis.
Grant (1941) states that most of the green frogs in northern Pontiac County, Quebec, are very dark with large black spots in some individuals, and Trapido and Clausen (1938) mention heavy spotting in specimens from the valley of the Little Cascapedia River, Quebec.
It is obvious from this evidence in the literature that unusually heavy markings and darkening may be expected to occur at least sporadically in some of the northernmost portions of the United States, such as the Lake Superior region, the Adirondacks. of New York, and parts of Vermont, New Hampshire and Maine, in addition to areas in Canada. This is borne out by the preserved material available.
Little Canadian material, aside from 3 0 adults from the collection of the Royal Ontario Museum of Zoology, was examined. A large series, how¬ ever, was available from Michigan, and the following characteristics were noted in material from the eastern upper peninsular and northern lower peninsular portions of the state, particularly Alpena, Montmorency, Che¬ boygan, Crawford, Oscoda, Roscommon, Chippewa, Luce, Mackinac, and Schoolcraft Counties: (a) There is a strong tendency to exhibit dorsal darkening. In many cases this is so pronounced that the dorsal spots are completely obscured, (b) There is a frequent intensification and darken¬ ing of markings; this produces, in many cases, greater contrast of these markings, and may possibly be correlated with a general increase in the amount of dark pigment. Spotting, anastomosing, or blotching on the sides may be increased. Similarly, marking on the lips, particularly the lower, is much more evident, being darker (black in most cases) and contrasting; in the case of throat and pectoral marking, when such is present, the pig¬ mentation is often quite dark to black, contrasting sharply with the white ground color, (c) The most striking feature of many specimens is a ver- miculate or anastomosing dorsal pattern resulting from an increase in the irregularity and number or size of spots on the back. When this marking is black on a lighter ground color, the effect is quite unusual and striking. The spotting or blotching may be superimposed upon a dirty mottled back¬ ground, and sometimes is margined by lighter areas in a fashion reminiscent of Rana septentrionalis.
Variation of exactly the same nature as that described above has been observed in specimens from St. Lawrence, Franklin, Essex, Herkimer, and Hamilton Counties in northern New York State. Frogs from this area show a high percentage of dark individuals with the corresponding intensifica¬ tion and increased contrast of the ventral and lateral markings. Spotting
1954, No. 1 March
The Green Frog
21
is heavier and there is the same tendency toward a striking dorsal anasto¬ mosing as described in the Michigan material. Scattered examples available from Vermont, New Hampshire, and Maine exhibit the same character¬ istics in varying degree, as do several specimens from Lake Nipigon, Ontario.
It should be emphasized that this variation is by no means constant. Its occurrence can best be described as sporadic. Often it is very difficult to detect, and a large number of specimens from the areas mentioned can¬ not be distinguished from those further south. Furthermore, no other sup¬ porting characters have been found which serve to distinguish this animal as a separate form. It is therefore the opinion of the writer that, in the absence of further evidence to the contrary, this far northern variation is not worthy of subspecific distinction, although the possibility still exists that if more material from the extreme northern limit of the range were available, a good subspecies might be found.
The region where the above described variation is apt to occur cor¬ responds surprisingly well with the range of the mink frog, Rana septen- trionalis, a species which these northern variants frequently resemble very closely. Moore (1952) has discussed at length the similarity between Rana clamitans and Rana septentrionalis in areas where both species occur. He points out that gene exchange between the two species is impossible due to their inability to produce viable hybrids, and postulates that the similarity is therefore the result of natural selection favoring the evolution of similar pigment patterns in the same environment. Another possibility which must be considered is that the dark northern variation in Rana clamitans is eco- phenotypic in nature; low temperatures may cause an excessive production of dark pigment.
CONCLUSIONS
It is clear from the evidence presented in the foregoing pages that the green frog can be divided into at least two recognizable and well de¬ fined geographic races. The first of these occupies the southern coastal plain from Texas to South Carolina. The other is found in the remainder of the range, extending into Canada. There is a possibility that a third subspecies in the most northern portion of the range can be defined, but the differ¬ ences encountered are sporadic, and the evidence at hand is too inadequate for any conclusion to be drawn as to the validity of such a race.
The type locality of Rana clamitans is Charleston, South Carolina. Although no topotypes have been examined, Charleston is undoubtedly within the range of the southern subspecies which should therefore be desig¬ nated as Rana clamitans clamitans Latrielle. The first name available for the northern race is Rafinesque’s Ranaria melanota, the type locality being the region of Lake Champlain and Lake George. This name is very inappropri¬ ate, but as a far northern race is not recognizable, the green frog in the remainder of the range must be designated as Rana clamitans melanota (Rafinesque) . The two forms may be briefly characterized as follows:
Rana clamitans clamitans Latreille
1. There is a complete absence of dorsal spotting in the adult and the back is a monochrome.
2. This is a smaller form than the northern subspecies. Adults rarely exceed 75 mm. snout-urostyle length. Because of this smaller size,
22
The Texas Journal of Science
1954, No. 1 March
FIG. 7. Spot map of the distribution of the two subspecies of Rana clamitans , based on counties from which specimens have been examined. No literature records have been included. Rana clamitans clamitans represented by solid symbols, Rana clamatans melanota represented by hollow symbols, and probable intergrades by half¬ solid symbols. The boundary of the coastal plain is represented by a broken line.
sexual dimorphism in size of tympanum becomes evident at a smaller head size.
3. The skin of the back is never rugose. Elevations on the sides are sparse and pointed.
4. Dorsal color is more brown than green. The face is usually bronze, and the yellow on the throat of the male is reduced or absent.
1954, No. 1 March
The Green Frog
23
The range approximates the southern coastal plain, an area which in¬ cludes .southern and eastern South Carolina, Florida, southern Georgia and Alabama, most of Mississippi, Louisiana, southeastern Arkansas, and eastern Texas.
Rana clamitans melanota (Rafinesque)
1. A large percentage of specimens show at least some dorsal spot¬ ting. Dorsal marking is unusually heavy in some areas at the north¬ ern extreme of the range.
2. This is a larger form than the southern subspecies. Adults frequently exceed 8 5 mm. snout-urostyle length. Because of the larger size, sexual dimorphism in size of tympanum does not become evident at as small a head size as it does in the southern race.
3. A rugose condition of the back is often encountered. Elevations on the sides tend to be larger, more numerous, and more flattened and rounded.
4. The predominant dorsal color is green, although darker individuals are sometimes encountered, particularly in the far north. There is usually a bright green to yellow green mask extending forward along the jaw from the tympanum, and the throat of the male is a brilliant yellow.
The range includes those areas not occupied by the southern subspecies. For a more accurate idea of the distribution of the two races, refer to the map, Fig. 7.
It should also be mentioned that head and tibia length are less, rela¬ tive to body length, in adult frogs of the northern race. However, direct comparison of northern and southern specimens of the same body length obscures this difference, because of the larger size of Rana clamitans melanota.
Differences were shown to exist in body proportions from east to west along the southern coastal plain. In Florida material the tibia length is significantly longer relative to body length than it is in either Texas or Louisiana material. On the other hand, although Texas and Florida frogs agree well on the basis of head length relative to body, southeastern Louisi¬ ana frogs have a significantly shorter head. In other words, all three samples are separable on the basis of mean ratios of head and tibia length relative to body taken together. These differences are not great enough in them¬ selves for subspecific recognition, although the distinctiveness of the south¬ eastern population is supported to some extent by ventral marking. As pointed out, however, the latter character is a variable one and is difficult to evaluate; it therefore seems best to regard these differences simply as evidence of incipient subspeciation in the southern race.
Little difference was found between eastern and western specimens of the northern race. There is an indication of a slightly longer tibia in the New York material, but New York frogs agree closely with Indiana and Michigan specimens in head length relative to body length.
SUMMARY
A detailed study was made of geographic variation in the green frog, Rana clamitans. Characters found to be subject to geographic variation include dorsal spotting, size, nature of the skin surface, ventral marking, color, and body proportions.
24
The Texas Journal of Science
1954, No. 1 March
The evidence advanced shows the green frog to be divisible into two well-marked geographic races. The more northern of these is designated as Rana clamitans melanota (Rafinesque) . The southern, coastal plain sub¬ species should be called Rana clamitans clamitans Latreille. The possibility that a far northern Canadian race may prove to be recognizable is brought to attention. An evaluation is made of the evidence supporting the existence of body proportion gradients with change in latitude in North American frogs, and it is suggested that shorter head length is correlated with shorter tibia length.
LITERATURE CITED
Agassiz, Louis — 1850 — Lake Superior. Boston, x + 428 p., front., pis., map. Breckenridge, W. J. — 1944 — Reptiles and amphibians of Minnesota. Minneapolis, Univ. of Minnesota, viii -j- 202 p., 52 fig., 45 maps.
Cope, E. D. — 1889 — The batrachia of North America. Bull. U. S. Nat. Mus. 34: 1-525, li9 fig., 86 pi.
Daudin, F. M. — 1802 — Histoire naturelle generale et particuliere des reptiles. Paris, 8 vol., 100 pi.
Daugherty, Anita E. — 1945 — A study of the pipiens complex of the genus Rana. Unpublished thesis, Univ. of Rochester. 36 p. 8 pi.
Dekay, James E. — 1842 — Zoology of New York, or the New York fauna. Part III. Reptiles and amphibia. Albany, iv + 98 p., 23 pi.
Dickerson, Mary C. — 1906 — The frog book. New York, xvii J- 253 p., 112 pi..
Fowler, J. A., and H. J. Cole — 1938 — Notes on some reptiles and amphibians from central Vermont. Copeia (2) :93.
GRANT, Ronald — 1941 — Salientia of northern Pontiac County, Quebec. Copeia (3) : 151-153.
Harlan, Richard — 1826 — Description of several new species of batracian reptiles, with observations on the larvae of frogs. Amer. Jour. Sci. 10:53-65.
HOLBROOK, John Edwards — 1842 — North American herpetology; or, a description of the reptiles inhabiting the United States. Ed. 2 Philadelphia, Vol. 4, col. pis.
Hurter, Julius — 1911 — Herpetology of Missouri. Trans. St. Louis Acad. Sci. 20: 59-274, pi. 18-24.
LE CONTE, JOHN- — 1824 — Remarks on the American species of the genera Hyla and Rana. Ann. Lyc. Nat. Hist. N. Y. 1(2) :278-282.
- 1855 — Descriptive catalogue of the Ranina of the United States. Proc. Acad.
Phil. 423-431.
LOGIER, E. B. S. — 1928 — Amphibians and reptiles of the Lake Nipigon region. Trans. Roy. Canadian Inst. 16: 279-291.
Moore,, John Alexander — 1944 — Geographic variation in Rana pipiens Schreber of eastern North America. Bull. Amer. Mus. Nat. Hist. 82(8) : 345-370, 3 fig-, 6 pi., 5 tab.
- 1952 — An analytical study of the geographic distribution of Rana septentrion-
alis. Amer. Nat. 86(826) : 5-22, 5 fig.
Oliver, James A., and Joseph R. Bailey — 1939 — Amphibians and reptiles of New Hampshire. Biol. Sur. Conn. Watershed, New Hampshire Fish and Game Dept. (4) : 195-221.
RAFINESQUE, C. S. — 1820 — Annals of nature; or, annual synopsis of new genera and species of animals, plants etc. discovered in North America. Lexington, 16 p. (privately reprinted by T. J. Fitzpatr ic, Iowa City, 1908).
1954, No. 1 March
The Green Frog
25
Rhodes, Samuel S. -1895 — Contributions to the zoology of Tennessee. No. 1. Rep¬ tiles and amphibians. Proc . Acad . Phil. 376-407.
Schmidt, Karl P. — 1938— A geogranhic variation gradient in frogs. Field Mm. Nat. Hist. Zoo. Set. 20(29) : 377-382.
Smith, Philip W., and Dorothy M. Smith — 1952 — The relationship of the chorus frogs, Pseudacris nigrita feriarum and Pseudacris nigrita triseriata. Amer. Midi. Nat. 48(1) : 165-180, 2 fig. 1 pi.
SONMINI, Charles N. S., and P. A. Latreille— 1802 — Histoire naturelle des rep¬ tiles, avec figures dessignees d’apres nature. Paris. Vol. 2, 332 p., 21 pi.
TkaPIDO, Harold — 1940— On finding the mink frog in northern Vermont. New Eng. Field Nat. (7) : 11-14.
- — and Robert T. Clausen — 1938 — Amphibians of eastern Quebec. Copeia.
(3): 117-125.
Vogel, Howard H., Jr. — 1942 — A blue specimen of the "green frog," Rand, clami- tans. Proc. Ind. Acad. Set. 51:266.
Wright, Albert Hazen— 1932 — -Life histories of the frogs of the Okefinokee Swamp, Georgia . New York, xv -f- 497 p., front., 45 pi.
- 1949— Handbook of frogs and toads of the United States and Canada. Ed. 3-
Ithaca, xii -f- 640 p., 76 pi., 37 maps.
SOME SELECTED ASPECTS OF JUDICIAL COMMITMENTS OF THE MENTALLY ILL IN TEXAS
H. J. FRIEDSAM, C. D. WHATLEY, JR., AND A. L. RHODES North Texas State College
INTRODUCTION
Legal procedures for the commitment of mentally ill persons to state hospitals have undergone considerable change in the United States dur¬ ing the past century, and much of this change has involved the growth and decline in importance of the jury trial as a method of commitment. In the latter part of the last century many states adopted this method for the avowed purpose of protecting the rights of citizens, for preventing their wrongful commitments to mental institutions under lax legal safeguards, but within the past few decades the tendency has been to abandon the jury trial as detrimental to the person’s mental health and to seek legal safeguards for his rights in other directions.
Despite this trend, the jury trial is still the most important legal pro¬ cedure for committing a mentally person to a state hospital in Texas, where the law specifies that no person shall be indefinitely committed to a state hospital without first having been duly judged insane by a jury. The only significant modification of Texas’ legal machinery for the com¬ mitment of the mentally ill has been the addition of the non-jury, ninety- day commitment. Together these two methods are the principal legal routes by which the vast majority of the insane find their way into state hospitals. These procedures, particularly the jury trial method, have been widely dis¬ cussed in terms of their legal, psychiatric, and therapeutic implications, but little attention has been addressed to their sociological aspects. It is the object of this paper to repair a part of this deficiency by reporting the find¬ ings of a study designed to provide tentative answers to two questions:
(1) Are there important differences in selected characteristics of persons committed to mental institutions by jury trial and ninety-day procedures?"'
(2) What social factors are related to such aspects of jury trial proceed¬ ings as pre-hearing detention of respondents, relationships of petitioner and respondent, sources and nature of testimony, etc.?
METHOD AND LIMITATIONS
The principal focus of our research was centered on 200 cases of indefinite (i.e., jury) commitments to state hospitals from Dallas County which occurred during a period of slightly over one year. Additional data were gathered for comparative purposes for 100 cases of ninety-day com¬ mitments to state and federal hospitals, these occurring in a period of ap¬ proximately six months. In all instances the data referred to in this paper were extracted from court records of Dallas County.
# Jury trial commitments are often referred to as "indefinite” or even "perman¬ ent” commitments, and the ninety-day commitments are sometimes referred to as "temporary.”
26
1954, No. 1 March
Commitment of the Mentally I'll
27
The fact that this research rests upon data procured from public records is an indication of its limitations. Such records are not best known for their completeness or uniformity on subjects of a sociological nature. For example, certain information which is always a part of the record in jury hearings is not always required in ninety-day hearings. Again, it is not worthwhile to analyze evidence presented in hearings of the latter type, since it amounts to nothing more than a legal form signed by the proper persons; on the other hand, in jury hearings the evidence is, as will be shown later, of several kinds and from several sources. Finally, we would hesitate before generalizing from our data to other counties or to the state as a whole because Dallas is one of the state’s most highly urbanized coun¬ ties, and the degree to which our findings are valid for other localities is an open question.
DIFFERENCES IN SELECTED CHARACTERISTICS OF PERSONS COMMITTED BY JURY TRIAL AND BY NINETY-DAY PROCEEDINGS
Our data show differences in sex, age, race, and marital status of per¬ sons committed to mental institutions by jury and by ninety-day proceed¬ ings (see Table I). Specifically, slightly more than one-half of the persons committed by jury hearings were female, but in the ninety-day com¬ mitments only one-third were females. The mean age of persons "perma¬ nently” committed was roughly ten years above that of persons "tempo¬ rarily” committed. Negroes were committed with considerably greater fre¬ quency by jury hearings than by ninety-day hearings. A larger percentage of persons committed by ninety-day hearings were married, and a much smaller percentage were widowed. Single and divorced marital statuses do not appear to vary significantly in the two groups.
Our data do not permit a definitive explanation of the sources of these differences. However, it can be said with confidence that the patterns of marital status are undoubtedly a function of the difference in the age dis¬ tribution of the two groups. It can also be said with confidence that vet¬ eran status appears to be crucial with respect to the age and sex differences. Relatively few veterans appear to be committed by jury hearings to state
TABLE I
Selected Characteristics of Persons Committed by Jury Trial and by Ninety-day Proceedings
|
Characteristics* |
Jury Trial |
Ninety-day |
|
Sex (percent) |
||
|
Male |
45.5 |
66.0 |
|
Female |
54.5 |
34.0 |
|
Mean Age (years) |
||
|
Males |
48.4 |
38.7 |
|
Females |
50.6 |
42.4 |
|
Race (percent) |
||
|
White |
83.5 |
94.0 |
|
Negro |
16.5 |
6.0 |
|
Marital status (percent) |
||
|
Single |
24.5 |
25.7 |
|
Married |
34.7 |
55.7 |
|
Widowed |
23.5 |
5.7 |
|
Divorced |
12.2 |
12.9 |
|
Separated |
5.1 |
0.0 |
|
* Unknowns are assumed to have |
same distribution |
as known cases. |
28
The Texas Journal of Science
1954, No. 1 March
hospitals. In Dallas County at least the usual practice in cases involving veterans appears to be ninety-day commitment to a Veterans Administration hospital with any subsequent action being taken by such hospitals. Since the majority of veterans are still relatively young males, this practice would appear to account largely for observed age and sex differences in the two classes of commitments and indirectly therefore for observed differences in marital status. In passing it should be observed that if this hypothesis is correct, it casts grave doubt on the utility of generalizing about mental illness from state hospital populations to the general population of the state and on the utility of comparing the two populations except for very limited purposes.
Our data do not show the importance of the factor of veteran status with reference to the observed racial composition of the two groups under discussion. Whatever may eventually be shown in this regard, there are two alternative, or perhaps supplementary, hypotheses which may be men¬ tioned. First, although only gross data on economic status are available in the court records, we have good reason to believe that the ninety-day hear¬ ing is more often utilized by persons of high than of low economic status when veteran status is not a factor. This, coupled with known differences in the distribution of income to Whites and Negroes, strongly suggests that the observed difference is at least in part of an economic character. Second, the possible role of community racial attitud.s cannot be ignored, although it should be obvious that data based on court records are not ade¬ quate for testing this hypothesis.
One other important difference between the two types of hearings may be mentioned briefly. There is no doubt that the ninety-day hearing is by far the more expeditious of the two. The period between the filing of a petition for a hearing and the actual hearing was two days or less in 54% of the ninety-day hearings, and 84% of these hearings occurred within one week of filing. On the other hand, only 5,5 % of the permanent hear¬ ings occurred within one week after filing of the petition, and in approxi¬ mately one-third of these cases the hearing did not occur until more than two weeks after filing. Insofar as an expeditious commitment process may be of value to the mentally ill person, the advantage of the ninety-day procedure is obvious. Furthermore, it seems probable that this, plus the relative freedom of the ninety-day hearing from unwanted publicity, abase¬ ment, or social stigma characteristic of the jury trial hearing, probably accounts in no little part for the apparently greater use of it by persons of high economic status. It seems likely that these advantages are pointed out to members of the families of mentally ill persons by doctors and by lawyers who are familiar with both types of hearings.
PRE-HEARING CUSTODY AND TREATMENT
The significance of a short time interval between petition and hear¬ ing becomes more obvious if we consider the custody and/ or treatment of the mentally ill person prior to the hearing. Of the 200 persons involved in our jury trial cases, 54 were in a state hospital on ninety-day commit¬ ments at the time of their hearings for indefinite commitment. Of the re¬ maining 146, 33% were or had been detained in jail immediately prior to their hearings, 25% were detained in the city-county hospital, 25% had
1954, No. 1 March
Commitment of the Mentally I'll
29
been in both hospital and jail, 11% were in private sanitariums or rest homes, and the remaining 6% were kept at home by members of their re¬ spective families.
This distribution raises obvious questions regarding the causes or considerations which determine whether a given person will be kept in one rather than another of these places. Reasoning from conventional opinions held about the nature of insanity, nothing may seem more natural than the practice of keeping mentally ill persons in jail until they can be placed safely in special institutions. However, our data suggest that jail or other types of pre-hearing custody is strongly influenced by social considerations. Specifically, it appears that social status and social attitudes combine with considerations of expediency to determine where most mentally ill persons are kept before their hearings. We have already indicated that there is reason to believe that economic status is important in accounting for the 54 persons who were in a state hospital on ninety-day commitments at the time of their indefinite commitments. As might be expected, our data show conclusively that economic status was also crucial for those kept in private sanitariums or rest homes. Conversely, no person who possessed property beyond a moderate amount was jailed. Community racial atti¬ tudes appear to affect the probability of confinement in jail, for there was a noticeably higher proportion of Negroes than of Whites who were so confined. The role of community attitudes upon pre-hearing custody is also reflected in the fact that almost twice as many males as females were kept in jail. That attitudes toward particular symptoms of mental illness are also factors in this situation is suggested by the fact that only one person exhibiting symptoms of depression, as indicated in trial testimony, was incarcerated. However, it should be pointed out that symptoms of aggres¬ sion on the other hand did not necessarily lead to jailing.
THE PETITIONERS
From both a sociological and a legal standpoint the petitioner is one of the most important persons involved in commitment procedures, since it is the action initiated by him that determines whether or not the men¬ tally ill person is ever brought before a court, adjudged insane, and com¬ mitted to a hospital. A petitioner may be any interested person, public of¬ ficial, or kinsman who files a formal complaint in which another person is alleged to be of unsound mind. In practice, the petitioner is usually some fairly close relative of the mentally ill person. Our data show that a close relative (i.e., parent, spouse, child or sibling of the respondent) was the petitioner in approximately 83% of the 200 jury trial cases. If other rela¬ tives who were petitioners are added to these, then petitioners were related to respondents in 94% of the cases.
Children of respondents appeared as petitioners most frequently (24.5%), followed by spouses (22.0%), parents (21.0%), and siblings (15.0%). The frequency with which children appear as petitioners is ap¬ parently a function of the high proportion of all permanent commitments who are aged persons. Further evidence to support this contention is found in the fact that children were petitioners in 27.5% of the cases involving Whites but only 9.1% of the cases involving Negroes. This difference de¬ rives significance from the fact that the mean age of Whites who were respondents was 11.5 years above that of Negroes. As would be expected,
30
The Texas Journal of Science
1954, No. 1 March
children appeared as petitioners in more than half of the cases involving respondents who were widowed. The frequencies with which spouses and parents appeared as petitioners need no special comment.
The percentages given in the foregoing paragraph must not be taken as indicative of the frequency with which persons "discover5’ symptoms of mental illness in members of their families. Judges and other court func¬ tionaries usually try to make sure that a petition is signed by a close rela¬ tive, if one is available, whether that person has had immediate knowledge of the respondent’s behavior or not. On the one hand, this helps in estab¬ lishing legal liability for support of the mentally ill person; and on the other, it assures the acquiescence and cooperation of the family in the com¬ mitment process. As we shall emphasize in the remainder of this paper, demonstration of this acquiescence appears to be the chief function, apart from the legal questions involved, of the jury trial procedure.
In an attempt to find some measure of the extent to which petitioners could be assumed to have had fairly extensive knowledge of the condition of respondents, we determined the number of petitioners and defendants who lives either at the same or at differe nt addresses and found that they had the same residence in approximately 67% of the cases. That this cri¬ terion has some validity is indicated by the fact that siblings and other relatives (i.e., those most likely to have been asked by officials or others to sign a petition) were petitioners in slightly less than 19% of the cases where petitioner and respondent lived at the same address, but were pe¬ titioners in approximately 44% of the cases where petitioner and respondent lived at different addresses.
SOURCES AND NATURE OF EVIDENCE
When a man is brought before a jury in a sanity hearing, there is theoretically a presumption of doubt as to the status of his sanity, a doubt to be decided from the weight of the evidence produced in court. In practice, as everyone knows, there is seldom any such doubt, and only rarely is a serious defense offered. Nevertheless, the state, having placed the judgment of sanity within the framework of a legal ritual, is obliged to furnish "evidence” to support the contention that the defendant is of unsound mind.
The most common source of such evidence was the oral testimony of witnesses. In most cases only one or at most two witnesses testified; and generally speaking, their testimony consisted of statements of observed pe¬ culiarities in the defendant’s behavior combined with the opinion, usually explicitly asked for by the state, that he was mentally unbalanced. Wit¬ nesses furnishing oral testimony may be conveniently divided into three groups. The first and most prevalent group of witnesses was composed of the defendant’s immediate family and other relatives, and these were usually the same persons who petitioned for the hearings. This type of witness testified in 87% of the total number of cases, and was the only type present in half of the cases. The second group of witnesses partici¬ pated in approximately one-third of the hearings, and was made up of persons acting in a professional capacity such as city and county medical personnel, physicians, and psychiatrists, but in all but 10 cases oral testi¬ mony from such sources was combined with that from family sources. Usually the role of professional witness was filled by the county health
1954, No. 1 March
Commitment of the Mentally III
31
officer. The third group of witnesses, and least important numerically, was a miscellaneous assortment of neighbors, police officers, clergymen, etc., who appeared at 12% of the hearings. There were only three hearings in which this was the only type of witness present.
Written evidence played a much less important role in these hearings than did the testimony of witnesses. If we eliminate the 54 cases of persons in state hospitals on ninety-day commitments, for each of whom there was a written statement to the effect that the person was not sufficiently re¬ covered to be released, written testimony was introduced in less than hT.f of the remaining cases. Such testimony was invariably from psychiatrists and physicians, but in practically every case it was offered in addition to oral testimony from the sources mentioned above. In 52 of the 54 c^s's of persons in state hospitals, and despite the fact that written test rn ny by members of the hospital staff was presented for each case, witnesses, usually family members, testified.
Since the person’s sanity was seldom in doubt in these hearings and since, if it were, the most important type of witness, members of the de¬ fendant’s immediate family and other relatives, were not professionally qualified to judge his sanity, it is obvious that the explanation for their appearance lies elsewhere. To be sure, they are convenient persons through whom the legal ritual involved may be completed, but it would seem that their major function is simply to assure the jury that the defendant is not being committed to a mental institution against the wishes of his family, and indeed, is being committed with their active cooperation.
Customarily, and for reasons which should now be obvious, no de¬ fense is offered in these proceedings. The defendant testified in less than one of every five cases, and in these his testimony was usually limited to the claim that he did not think he was "crazy” and that he should not be committed. Whether the court so intended it or not, the nature of his testimony was usually such as to convince the jury of the necessity of commitment. A serious defense occurred in only one of the 200 cases, and as might be expected it not only involved more witnesses (seventeen) but also a larger estate than any other.
The most common behavior cited by witnesses as cause or reason for their opinion of the defendant’s alleged insanity was the aggressive or threatening character of his actions. The second most frequently mentioned behavior pattern was annoying, irksome, or irresponsible actions by the defendant. From what we have gathered in analyzing the testimony, it seems that both to the family and the community the defendant was viewed either as a potential source of harm or as a nuisance. These two patterns are plainly indicated by the frequencies with which they were mentioned by witnesses to describe the defendant’s actions:
1. Aggressive actions
a. Threatens or attacks others (50)
b. Dangerous or violent (29)
2. Annoying, irksome or irresponsible actions
a. Runs off or wanders about aimlessly (26)
b. Neglectful of person and unable or unwilling to hold job (2 5)
c. Forgetful, confused, irresponsible (18)
32
The Texas Journal of Science
1954, No. 1 March
It is possible, of course, that these frequencies are simply an index to the behavior of all mentally ill persons in the community. However, the emphasis on aggressive behavior suggests two alternative hypotheses: first, that the persons committed to state hospitals are in no little part selected by virtue of their aggressive behavior; second, that the testimony on ag¬ gressiveness reflects the prevailing community attitude that mentally ill persons are dangerous. Data from court records are obviously not sufficient to test either of these hypotheses, but there is a hint of support for the latter in the fact that professional witnesses did not appear to emphasize aggressive behavior as much as did lay witnesses.
CONCLUSIONS
In summary, our data indicate that there are important differences in selected characteristics of persons committed to mental institutions by ninety-day and by jury trial procedures. These differences appear largely to be functions of veteran status and economic status. Our data also indi¬ cate that social attitudes and status are important factors in determining the pre-hearing custody of persons committed by jury trial. Finally, it appears that sociologically the jury trial functions primarily as a means of insuring family acquiescence and cooperation in the commitment process.
THE MAMMALS OF TWO AREAS IN THE BIG BEND REGION OF TRANS-PECOS TEXAS
J. R. TAMSITT The University of Texas
INTRODUCTION
This report is based on a survey of the mammalian fauna of two lo¬ calities in southern Trans-Pecos Texas (see Fig. 1). This survey was made in an attempt to determine the mammalian species found in these two lo¬ calities and to learn their ecological distribution. A survey of this nature has never been made in these two areas, although previous work in the Chihuahuan biotic province in Trans-Pecos Texas has been done in the Davis Mountains by Blair (1940), in the Big Bend Park area by Porell and Bryant (1942), in Culberson County by Davis and Robertson (1944), in the Sierra Vieja region by Blair and Miller (1949), and on the Stockton Plateau of northeastern Terrell County by Herrmann (1950). The mam¬ malian fauna of the Guadalupe Mountains was investigated by Davis (1940). Bailey (1905) did some work in the Trans-Pecos region in his biological survey of Texas. With the exception of the work done by Herrmann (op. cit.) , previous investigations, as well as this survey, have been mostly limited to the mountainous regions of Trans-Pecos Texas. The present report is concerned with work done in the Black Gap area, Brewster County, and the La Mota Mountain area, Presidio County, Texas. The Black Gap area is a state wildlife management area located 50 airline miles southeast of Marathon, Texas. The La Mota Mountain area is 53 air¬ line miles south of Marfa, Texas.
The phase of the survey concerning the distribution of the mammals of the La Mota Mountain area is based on field work done from June 3 to July 4, 1952, by W. W. Milstead and myself. Milstead (in press) studied the ecological distribution of the lizards of the area.
The investigation of the Black Gap area was made from June 7 to July 12, 1951, by the author and 13 advanced zoology and geology stu¬ dents of the University of Texas under the supervision of Dr. W. Frank Blair. Additional collections in the area were made from December 28 to December 31, 19 51 by W. L. Thompson and T. E. Kennedy. The work reported here represents one phase of an ecological distribution study of the vertebrates of the Black Gap area. The vegetation of the area and the ecological distribution of the summer birds were studied by Thompson ( 1953 ). The ecological distribution of the reptiles and amphibians was investigated by Ralph Axtell (unpublished), J. P. Brand, and Richard Newman. H. S. Al-Uthman (1952) investigated geographic variation of Perognathus merriami in this and other localities. W. W. Milstead did a comprehensive study of the lizard genus Cnemidophorm in the Black Gap area, in the La Mota Mountain area, and in the Sierra Vieja region. Small mammal collections were made by E. T. Ashworth, J. W. Raine, J. R. Barker, Gilbert Magee, T. J. Cordray, J. W. Broughton, and myself. Louis
33
34
The Texas Journal of Science
1954, No. 1 March
Follansbee completed a brief census and home range study of the small mammal populations. William Hightower, an entomologist from the Texas State Department of Health, collected the ectoparasites found on the mam¬ mal specimens collected.
PHYSICAL FEATURES
The Black Gap area of Brewster County, Texas, is located seven miles northeast of Big Bend National Park. A former ranch comprising 46,000 acres, the Black Gap area occupies a large basin approximately 2,000 feet above sea level. On the southwest the basin is bounded by Stairway Moun¬ tain, which is 5,000 feet at its highest point. On the north it is bounded by the Cretaceous high which separates the folded Mesozoic strata of the Black Gap area from the folded Paleozoic strata of the Marathon Basin. On the south the area is bounded by the Sierra del Carmen Range of Mexico; and on the east it is bounded by the relatively undisturbed Cretaceous strata of the western margin of the Edwards Plateau.
Within the Black Gap basin the geologic structure is quite complex, and the topography is very uneven. High Cretaceous peaks and buttes, mostly capped by basaltic Tertiary lava, interrupt rolling hills surfaced by limestone fragments. All limestone strata are of Cretaceous age, while the lavas are of Tertiary age. Wilson (1951) found the limestones to be of both the Comanche and Gulf series, extending from Glen Rose age in the Comanche to Boquillas and Terlingua age in the Gulf series. The most complete Cretaceous section of the area is found in the eastern front of Stairway Mountain. East of Stairway Mountain the low hills are capped by several distinct basaltic lava flows; and approaching the Rio Grande, the hills are dissected by deep canyons, forming soft limestone terraced slopes above steep resistant limestone cliffs.
Several dry stream courses follow the canyon and valley floors; and Maravillas Creek, the largest of these, forms the northeastern boundary of the area. In general, older rocks are encountered southward from Mara¬ villas Creek toward the Rio Grande.
The headquarters of La Mota Rancho are located in Presidio County, Texas, and are situated in a shallow basin between La Mota Mountain and the Tascotal Mesa. The ranch covers 3 8,400 acres and is subdivided into several pastures, the largest of which are Alamo Seco, Ocotillo, Javalin, Escondido, and Los Fresnos. The latter is the pasture in which the ranch headquarters are located. Alameda pasture is the large pasture to the west of Los Fresnos pasture, and Torneros Creek, the principal drainage of the area, follows the Tascotal Mesa fault through this pasture. Alamo Seco and Ocotillo pastures are located toward the north on the Tascotal Mesa. Javalin and Escondido pastures encompass the low rolling hills and rock bluffs adjacent to the mesa.
La Mota Mountain is approximately three miles south of the ranch headquarters, and the south fence of the ranch passes over the summit of the mountain. The Tascotal Mesa has an altitude of 5,180 feet at its high¬ est point, and La Mota Mountain reaches an altitude of 5,046 feet. The ranch headquarters are at an elevation of 3,900 feet. The elevation varies from 3,700 feet to 4,400 feet in the area between La Mota Mountain and the Tascotal Mesa. The geology of the area has been studied by Erickson (1951).
1954, No. 1 March
Mammals of Trans-Pecos Texas
35
Fig. 1. Map of the Big Bend region, with the principal mountain ranges and the two areas studied, the Black Gap area and the La Mota Mountain area.
The two formations that comprise most of the surface rock of the La Mota area are the Tascotal tuff and the Rawls basalt, both members of the Tertiary Buck Hills volcanic series. The Tascotal tuff is very light in color and consists of three types of rock: a rhyolitic tuff, sandstone and conglomerate, and conglomerate and fresh-water limestone. The Rawls basalt is very dark in color and consists of four types of rock: volcanic
3 6
The Texas Journal of Science
1954, No. 1 March
breccia, trachybasalt porphyry, basalt, and trachyandesite porphyry. In some localities the Tascotal tuff is extensively exposed, but generally it is covered by Rawls basalt, which covers most of the area.
The topography of the area, marked by buttes, peaks, and many can¬ yons, is due to the weathering of the dense nonporphyritic flows to thin, slabby pieces which generally form gentle slopes, while the fine-grained porphyritic flows of the Rawls basalt weather to steep slopes and irregular scarps. According to Erickson (op. cit.) , the rugged topography is pro¬ duced by the alternation of the porphyritic and nonporphyritic flows.
Climatologically, Brewster and Presidio Counties are included in Thornwaite’s (1948) arid zone with a moisture index of -60 to -40 (mois¬ ture deficiency between 40 and 60). The areas studied are located in a rain¬ fall belt of 12 to 14 inches a year (Yearbook of Agriculture, 1941). Most of the rain falls in June, July, and August, and the average annual rainfall, as measured at Presidio in Presidio County, is 10.23 inches. During our stay in June, 1952, rain fell on seven days at the La Mota Rancho head¬ quarters.
At Presidio, temperatures range from a maximum of 112° F to a minimum of 11° F. The maximum temperature at Black Gap during our stay was 114° F. The average daily temperature at Fa Mota Rancho head¬ quarters in June, 1952, was 8 5.69° F, with an average maximum of 96.52° F and an average minimum of 72.75° F. The highest temperature recorded during our stay at La Mota was 106° F and the lowest recorded was 68° F. The average daily temperature range was 24.10° F. The preceding sta¬ tistics were taken from Milstead (in press).
ECOLOGICAL ASPECTS
Following the ecological classification of Weaver and Clements (193 8), Brewster and Presidio Counties fall in the desert grassland climax. Tharp (1939) placed the Black Gap and La Mota Mountain areas in his Sotol- Lechuguilla and Inter-Mountain .Valley division of the Fcothills and Mesa Region westward from the Pecos River. These two areas are included in the Chihuahuan biotic province as defined by Dice (1943) and Blair (1950). Floral and faunal .considerations were the basis for the formula¬ tion of the biotic provinces in Texas. The Chihuahuan biotic province embraces all of Trans-Pecos except the Guadalupe Mountains of northern Culberson County and has its northern limit in southern New Mexico and extends southward into the Mexican states of Coahuila and Chihuahua.
In working with animal distribution, a mode of classification based on habitat is a useful and necessary instrument when dealing with a group of species within a given area. A certain species in a locality may be re¬ stricted to a particular habitat or may be found in two or more micro¬ habitats, e.g., Pero gnat bus nelsoni , which occurs on the lava rock and rock bluffs of the La Mota Mountain area (see Table I), and PerognatJous mer- riami , which is found in a variety of habitats at Black Gap (see Table II). In a region as physiographically diversified as the Trans-Pecos, a multi¬ formity of microhabitats may be found in a very limited area. One micro¬ habitat may possess a distinctive characteristic environment, i.e., a soil type, altitude, or be described by the presence of an index plant or plants. These habitats may be limited and often discontinuous, but, with the ani¬ mals that occur in them, may be grouped by basic similarities into an "as¬ sociation,” i.e., the plants and animals that occur together in a relatively
1954, No. 1 March
Mammals of Trans-Pecos Texas
37
stable environment. The ecological associations of the Black Gap and La Mota areas are defined by vegetation, topographic regularities, and soil type features common to a given locality or localities.
In the past the terminology applied to an association has been based on the dominant vegetation found in that association. With the exception of two associations, the rock bluff association of La Mota and the rocky canyons and cliffs association of Black Gap, the terminology applied to the associations of the two areas under consideration is determined by the dominant vegetation of the association. However, this terminology is some¬ what arbitrary and may be derived from physiographic or topographic fea¬ tures of the association. The mesquite-mountain ash-cottonwood associa¬ tion of the La Mota area may be correctly termed a ''stream bank” or "stream bed” association. Likewise, the mesquite-creosote bush association of that area would be tantamount to "flood plain” association.
TABLE I
Number of mammal specimens collected, sight records or other evidence (x), where specimens were not collected, in seven ecological associations on La Mota Rancho, Presidio County, Texas.
O
O
p£
a
o
U
Species of Mammals
<3
SH
£0
5
3
6/j
P
J3
P
U'
OO
|
Pipistrellus hesperus |
X |
X |
3 |
|||
|
Antrozous pallidus |
X |
X |
4 |
|||
|
Lepus calif ornicus |
X |
X |
X |
X |
X |
|
|
Sylvilagus auduboni |
X |
1 |
X |
|||
|
Citellus variegatus |
X |
|||||
|
Citellus interpres |
X |
2 |
1 |
|||
|
Citellus spilosoma |
1 |
3 |
4 |
|||
|
Thomomys sp. |
X X |
X |
||||
|
Cratogeomys castanops |
1 |
X |
||||
|
Perognathus merriami |
3 |
11 |
1 |
|||
|
Perognathus nelsoni |
1 |
11 |
||||
|
Perognathus penicillatus |
2 |
4 |
24 |
8 |
||
|
Dipodomys merriami |
6 |
5 |
14 |
|||
|
Peromyscus eremicus |
4 |
3 |
||||
|
Peromyscus pectoralis |
1 |
2 |
||||
|
Neotoma albigula |
2 |
|||||
|
Urocyon cinereoargenteus |
X |
X |
||||
|
Bassariscus astutus |
X |
|||||
|
Conepatus mesoleucus |
X |
|||||
|
Felis rufus |
X |
|||||
|
Odocoileus hemionus |
X |
X |
X |
X |
38
The Texas Journal of Science
1954, No. 1 March
ECOLOGICAL ASSOCIATIONS OF THE BLACK GAP WILDLIFE MANAGEMENT AREA
Thompson ( 195 3 ) collected 54 families of plants represented by a total of 169 species from the Black Gap area. The vegetation is primarily xeric, but moisture-loving forms such as walnut, buckeye, Mexican per¬ simmon, and mesquite grow abundantly along stream beds and around stock tanks. Various cacti are profuse throughout the area. The rocky lime¬ stone hills support a sparse vegetation of such woody plants as creosote bush, catclaw, lechuguilla, and sotol. A dense vegetation of forbs, grasses, sotol, and yucca is found on the lava hills and slopes. The information re¬ lating to the ecological associations occuring in the Black Gap area is pri¬ marily from Thompson ( op: cit .).
PERSIMMON-WALNUT ASSOCIATION
This association is characteristic of stream banks, and the most dense vegetation of the area is found in the persimmon-walnut association. The Mexican persimmon ( Brayodendron texanum ) is quite abaundant, and often the walnut ( Juglans rupestris ) supplements it along the larger stream beds. The prickly hackberry ( Momisia pallida ), bee brush ( Aloysia ligustrina) , milkwort (Poly gala alba), Eysenhardtia amorphoides , Convolulus incanus, Berberis trifoliolata, allthorn (Koeberlinia spinosa) , butterfly bush (Budd- leia marrubii folia) , redberry (Schaeferria cunei folia) , and the desert willow (Chilopsis linearis) are found with the persimmon in this association.
The most common small mammals were the rock pocket-mouse ( Perog - nathus nelsoni) and the Merriam pocket-mouse (Perognathus merriami) , these being the only species of mammals which were found in all the as¬ sociations of the area (see Table II). All but four of the canyon bats (Pipistrellus hesperus) collected were shot over tanks or ponds in this as¬ sociation. The hog-nosed skunk (Conepatus mesoleucus) is largely restricted to the stream beds and creek bottoms of the area. In this association were seen mule deer (Odo coileus hemionus) , the javelina ( Tayassu tajacu) , the little spotted skunk ( Spilogale gracilis), and tracks of the bobcat (Feiis rufus ) .
MESQUITE-HUISACHE ASSOCIATION
The plants of this association grow in the deep sand and gravel of flood plains and on the edges of artificial ponds. The mesquite ( Prosopis glandu- losa) and several acacias, principally Acacia vernicosa, comprise the domi¬ nant vegetation. Other plants found growing on the flood plain are all¬ thorn, prickly hackberry, lotewood (Z izyphus lyciodes) , condalia (Condalia spathulata) , Parthenium incanum, Solanum elaegni folium, Ambrosia psilo- stachya , false grama (Cathestecum erectum) , three awn ( Aristida wrighti) , and Triodia elongata. Woody plants bordering the tanks are mesquite, acaci¬ as, tree tobacco (Nicotiana glauca) , and Baccharis sp. Common on the banks are Phyla nodiflora, Nicotiana trigonophylla, Solanum elaegni folium, paperflower (Psilostrophe gnaphaodes) , grama grass ( BotUeloua trifida) , and Bermuda grass ( Cynodon dactylon) .
Most of the four-toed kangaroo rats (Dipodomys merriami) and the Merriam pocket mouse (Perognathus merriami) collected at Black Gap were from this association. Other species were somewhat scarce, and the least number of Perognathus nelsoni collected in any one association was
1954, No. 1 March
Mammals of Trans-Pecos Texas
3 9
in this association. The only specimen of the hooded skunk ( Mephitis macroura ) taken in the area was collected in this association, but this wide- ranging species probably occurs in other associations. The mounds of the mountain pocket gopher (T homomys sp. ) were occassionally seen. More specimens (23.9 per cent) were collected in this association than in any other association of the Black Gap area.
ROCKY CANYONS AND CLIFFS ASSOCIATION
The hills of the Black Gap area are dissected by many streams which form rocky canyons bounded by steep limestone cliffs. Other small can¬ yons descending from the top of the mesa, of which the rim rock is largely in the form of high cliffs, carry water runoff to the valley floor below. Triodia pilosa, T. elongata , muhly grass (Muhlenber gia p or ten) , Indian
TABLE II
Number of mammal specimens collected, sight records or other evidence (x), where specimens were not collected, in seven ecological associations of the Black Gap Wild¬ life Management Area, Brewster County, Texas.
a
o
>.
c
U
d
bt]
d
-c
|
Species of Mammals |
3 >H |
<D |
1 |
u O Ph |
d X |
o CO |
cd 4-4 0 |
|
Pipistrellus hesperus |
16 |
2 |
1 |
X |
1 |
||
|
Plecotus rafinesqui |
X |
16 |
|||||
|
Tadarida mexicana |
1 |
||||||
|
Lepus calif ornicus |
1 |
X |
X |
X |
|||
|
Sylvilagus auduboni |
1 |
X |
|||||
|
Citelus variegatus |
X |
X |
|||||
|
Citellus interpres |
X |
X |
1 |
9 |
X |
||
|
Citellus mexicanus |
1 |
1 |
|||||
|
Citellus spilosoma |
X |
||||||
|
T homomys sp. |
X |
X |
|||||
|
Cratogeomys castanops |
2 |
2 |
|||||
|
Perognathus merriami |
38 |
12 |
92 |
9 |
27 |
17 |
14 |
|
Perognathus nelsoni |
41 |
10 |
7 |
10 |
11 |
75 |
96 |
|
Perognathus penicillatus |
3 |
4 |
4 |
||||
|
Dipodomys merriami |
3 |
31 |
1 |
||||
|
Peromyscus eremicus |
7 |
3 |
2 |
3 |
7 |
1 |
|
|
Peromyscus pectoralis |
2 |
3 |
|||||
|
Neotoma albigula |
1 |
2 |
2 |
16 |
|||
|
Bassariscus astutus |
2 |
||||||
|
Mephitis macroura |
1 |
||||||
|
Spilogale gracilis |
X |
||||||
|
Conepatus mesoleucus |
1 |
||||||
|
Felis rufus |
X |
||||||
|
Felis concolor |
X |
||||||
|
Tayassu tajacu |
X |
||||||
|
Odocoileus hemionus |
X |
X |
X |
X |
X |
40
The Texas Journal of Science
1954, No. 1 March
paint brush ( Castilleja latebracteata) , Tecoma stans, Karwinskia humbolt- iana, and Parosela wrighti are shrubs and herbaceous plants found in this association.
All of the specimens of the long-eared bat ( Plecotus rafinesqui ) and the single Mexican freetail bat ( T ad arid a mexicana) were obtained from a limestone cave in this association. Other specimens included the canyon bat (Pipistrellus hesperus), Neotoma albigula, Perognathus nelsoni, Perog- nathus penicillatus, Peromyscus eremicus, and Perognathus merriami. Dur¬ ing our stay at Black Gap, a mountain lion ( Felis concolor ) killed a goat at the entrance to a limestone cave. Antelope squirrels ( Citellus inter pres) were often seen scampering over rock cliffs and canyon faces.
HUISACHE-CREOSOTE BUSH ASSOCIATION
This association is found on the rolling hills and basins in very rocky limestone and is the most extensive association in the Black Gap area. The dominant vegetation is the huisache (Acacia vernicosa ) and the creosote bush ( Larrea trident at a) . Croton neomexicanus, Triodia elongata, sand dropseed ( Sporobolus cryptandrus) , and Mozinna spathulata were also com¬ mon in this association, as were various cacti.
The Merriam pocket-mouse (Perognathus merriami) was the most abundant mammal, but Perognathus penicillatus, Perognathus nelsoni, Neotoma albigula, and Citellus interpres were present in smaller numbers. The rock squirrel (Citellus variegatus) was seen only once in this associa¬ tion. Jackrabbits (Lepus calif ornicus) were common in this association as well as in the mesquite-huisache and the sotol-lechuguilla association. The specimens of mammals collected here comprised 7.3 per cent of the total number of specimens taken in the area.
SOTOL-LECHUGUILLA ASSOCIATION
Sotol (Dasylirion leiophyllum) and lechuguilla (Agave lechuguilla) are the dominant plants on the lower edges of lava talus slopes and on the upper slopes of the limestone hills. Commonly found with the dominant plants are Triodia elongata, muhly grass, Yucca sp., Mozinna spathulata, red berry, and various cacti.
The abundance of lechuguilla in this association afforded excellent food for the mountain pocket gopher (Thomomys sp.). Perognathus nelsoni was the most abundant mammal both in this and in the grama-prickly pear association. The antelope squirrel (Citellus interpres) and the white-throated packrat (Neotoma albigula), with 16 records, were largely restricted to this association. Peromyscus pectoralis was found only in the mesquite- huisache association. Peromyscus eremicus, with seven records, was more abundant in this association and in the yucca terrace association than in the other four associations in which it was found. Of the 612 specimens collected, 21.1 per cent came from this association.
GRAMA-PRICKLY PEAR ASSOCIATION
This association is found on the upper talus slopes and the lava peaks of the area. Thompson ( 195 3 ) recorded a particularly long list of plants from this association. A much heavier growth of grass was found on the lava peaks and upper talus slopes than on the limestone slopes. Because the limestone is much more readily dissolved by weathering, the soil derived
1954, No. 1 March
Mammals of Trans-Pecos Texas
41
from the lava appears to be deeper than that derived from the limestone. Three grama grasses {Bouteloua trifida, B. uni folia, B. breviseta) were es¬ pecially abundant. Ocotillo ( Fouquiera splendens) , yucca, and lechuguilla were also present in this association.
The most abundant small mammal in the lava areas was Perognathus nelsoni. The ringtail ( Bassariscus astutus) was restricted to this rocky as¬ sociation, and the cactus mouse ( Peromyscus eremicus) and the desert pocket-mouse ( Perognathus penicillatus ) were somewhat scarce. Only 18.6 per cent of the 612 specimens collected were from this association.
YUCCA TERRACE ASSOCIATION
This association is rather limited in the Black Gap area. It reaches its maximum development at the base and proximal slopes of the northern extremities of Stairway Mountain, where the yucca is most abundant. It is found on a terrace overlooking Javelina Creek on the east and on a few isolated terraces overlooking canyons and creek bottoms. Sotol, lechuguilla, various cacti ( Opuntia phaeacantha, Opuntia rufida, Opuntia leptocaulis) , and a sparse population of catclaw ( Acacia greggi) , mesquite, creosote bush, and some grama grass are found growing with the dominant plant.
Sight records were obtained for the mule deer ( Odocoileus hemionus ) and the spotted ground squirrel ( Citellus spilosoma) . The cactus mouse ( Peromyscus eremicus ), the white-throated packrat ( Neotoma albigula) , and the four-toed kangaroo rat ( Dipodomys merriami) were scarce, but Merriam’s pocket-mouse ( Perognathus merriami) was abundant.
ECOLOGICAL ASSOCIATIONS OF THE LA MOTA MOUNTAIN AREA
The distribution of plants at La Mota corresponds to that at Black Gap with few exceptions. The limited limestone areas support a dense growth of creosote bush, mesquite, and catclaw. A sparse vegetation of grasses, yucca, sotol, lechuguilla, and beargrass is found on the lava hills and on La Mota Mountain. Along the stream banks, on dry creek beds, and at the numerous springs of the area, an extremely dense underbrush of mesquite and catclaw is interrupted by towering cottonwood ( Popuhis deltcides) and large mountain ash ( Fraxinus velutina) trees. In many places along Torneros Creek and on adjoining alluvial fans, the desert willow forms an impenetrable thicket. As at Black Gap, various cacti are found in all associations.
LECHUGUILLA -BEARGRASS ASSOCIATION
This association has a limited extent on La Mota Mountain where it covers the entire summit. The most abundant plants are the lechuguilla {Agave lechuguilla) and the beargrass {Nolina erumpens) , which are scat¬ tered in clumps over the summit. The stand of lechuguilla is broken only by large basaltic rocks and other minor plants which are widely scattered throughout this association. Other vegetation includes yucca {Yucca sp.), sotol ( Dasylirion leiophyllum) , ocotillo {Fouquiera splendens) , and grama grass {Bouteloua breviseta). Plants of lesser importance include catclaw {Acacia greggi), ephedra {Ephedra trifurcata ), blackbrush {Condalia mexicana) , mesquite {Prosopis glandulosa) , sumac {Rhus virens), golden¬ eye {Viguiera stenoloba) , salt brush {Atriplex canes cens ) , and whitebrush {Aloysia wrighti) . The soil and rocks of this association are of Rawls basalt.
42
The Texas Journal of Science
1954, No. 1 March
This association was trapped from June 20 through June 22, 1952. The fauna of this ascociation was very sparse, and only one encinal mouse ( Peromyscus pector alls) was taken. The mountain pocket gopher ( Tho - momys sp. ) is probably the most common small mammal of this ascocia¬ tion.
ROCK BLUFF ASSOCIATION
This is a discontinuously distributed association which is found on La Mota Mountain and on the steep canyon walls throughout La Mota Rancho. The surface rocks, cliff faces, and soil of this association are of the Rawls basalt and the Tascotal tuff. The latter is somewhat limited in areas occupied by this association. The former is found on the upper reaches of La Mota Mountain and throughout the ranch overlooking creek beds and numerous gullies and valleys. Mot included in this association are the small rock outcrops and ridges found throughout the area, and they are treated as part of the association in which they occur.
The vegetation on the rock bluff is sparse or absent, for the plants grow only where dirt or soil has collected in the cracks of the rock. Cat- claw, blackbrush, ephedra, beargrass, and grama grass are found at the base of the rim-rock on La Mota Mountain. The rock bluff, in most cases, is not a continuous sheet of rock but possesses many outcrops and breaks. Sotol, yucca, ocotillo, beargrass, ephedra, lechuguilla, leather weed ( J aim pa spathulata) , and the hop tree (V tele a sp.) grow on the rock bluff of La Mota Mountain. On the light-colored, Tascotal rock bluff little vegetation is present. At the base are found blackbrush, creosote bush, catclaw, and, at various places, ocotillo, sotol, and yucca.
The rock bluff of La Mota Mountain was trapped from June 19 through June 22, 1952. The light-colored rock bluff was trapped from June 11 through June 14, 1952. The mammals taken from this association constituted a small percentage (4.1 per cent) of the total number of speci¬ mens collected. The rock pocket-mouse ( Pemgnatbus nelsoni) , the encinal mouse ( Peromyscus pector alls) , the cactus mouse ( Peromyscus eremicus) , and the antelope squirrel (Citellus inter pres) were the only mammals col¬ lected in this association, and they were quite scarce.
SOTOL-YUCCA-BEARGRASS ASSOCIATION
This association is found on the steeper rocky slopes of La Mota Moun¬ tain. The dominant plant is sotol, with yucca and beargrass scattered over the slopes of the mountain. Present on the lower slopes are catclaw, creosote bush, ocotillo, lechuguilla, and blackbrush, with blackbrush the least abundant and sotol and yucca the most abundant. On the higher slopes near the rock bluff, the creosote bush, catclaw, and ocotillo are replaced by ephedra, which is quite dense at the base of the rim rock. The soil, rocks, and boulders are of Rawls basalt. This association was trapped from June 19 through June 22, 1952.
No specimens were collected in this association. The jackrabbit ( Lepus calif ornicus ) , the desert cottontail ( Sylvilagus auduboni) , the mule deer ( Odocoileus hemiomis) , and the antelope squirrel ( Citellus inter pres) were seen. A large number of mounds indicated that the mountain pocket gopher ( Thomomys sp.) was the most abundant mammal.
1954, No. 1 March
Mammals of Trans-Pecos Texas
43
OCOTILLO-CATCLAW ASSOCIATION
This association occupies the rough and broken country between La Mota Mountain and the Tascotal Mesa where there is a high percentage of rock cover. It is found around the base of La Mota Mountain and is the dominant association of the area. It occurs on the tops and slopes of the low hills of La Mota Rancho and is characterized by the presence of rock outcrops, large boulders, and much loose rock. The surface rocks are prin¬ cipally Rawls basalt, but in a few places the Tascotal tuff is exposed. This association appears to be limited to the dark, rocky soil and occurs on the Tascotal Mesa where the terrain is least hilly and most gently rolling.
The dominant vegetation is made up of ocotillo, which occurs through¬ out the association except on the rock outcrops, and catclaw, which has a distribution comparable to the ocotillo. Other plants of the association are creosote bush, sotol, yucca, beargrass, allthorn ( Koeberlinia spinosa) , and senna ( Cassia lindheimeriana) .
This association was trapped from June 4 to June 8, and from June 11 to June 14, 1952. Thirty specimens, which represent 24.6 per cent of the total prepared, were collected from this association. All but one specimen of the rock pocket-mouse (Pero gnat bus nelsoni ) taken in the area was from this association. The rock-loving white-throated packrat ( Neotoma albigula) appears to be limited to this association. The desert cottontail ( Sylvilagus auduboni) , although found in other habitats, was collected only from this association. Antelope squirrels ( Citellus inter pres) , desert pocket- mice ( Perognatbus penicillatus) , four-toed kangaroo rats ( Dipodomys mer- riami) , and cactus mice ( Peromyscus eremicus) were collected but were scarce. A bobcat ( Felis rufus) was killed in this association by one of the ranch hands prior to our arrival at La Mota Rancho. Sight records were obtained for the jackrabbit ( Lepus calif brnicus) , the mule deer ( Odo coileus hemionus ) , and the canyon bat ( Pipistrellus he s perus) .
CREOSOTE BUSH-OCOTILLO ASSOCIATION
This association is less extensive than the other associations and is found on the gentle slopes, very low rolling hills, and on terraces above the flood plain between La Mota Mountain and the Tascotal Mesa. However, it is the most extensive association on the Tascotal Mesa, where lechuguilla is as abundant as the creosote bush and ocotillo. There is very little rock cover, and the soil is gravelly and reddish-brown in color. This association is found on both the Rawls basalt and the Tascotal tuff.
The vegetation is very sparse, and in many places the creosote bush and the ocotillo comprise the only vegetation. Other plants are mesquite, huisache ( Acacia constrict a) , catclaw, blackbrush, sotol, yucca and all¬ thorn.
This association was trapped from June 11 to June 14, 1952. The Merriam pocket-mouse (Pero gnat bus merriami) appeared to be largely re¬ stricted to this association. The single plains pocket-gopher ( Cratogeomys castaops) obtained in the area was from this association, and the mounds of this gopher were frequently seen in this association as well as in the mesquite-mountain ash-cottonwood association. Specimens of the spotted ground squirrel ( Citellus spilosoma) , the desert pocket-mouse (Pero gnat bus penicillatus ), the cactus mouse (Peromyscus eremicus) , and the four- toed kangaroo rat (Dipodomys merriami) were also obtained. The mounds of the
44
The Texas Journal of Science
1954, No. 1 March
mountain pocket gopher ( Thomomys sp.) were occasionally seen. The jack-rabbit ( Lepus calif or nicus) , and the mule deer ( Odocoileus bemionus ) were seen on numerous occasions in this association.
MESQUITE-CREOSOTE BUSH ASSOCIATION
This association is a flood plain association, for it is found on the Tascotal Mesa and in the area between the Mesa and La Mota Mountain only on fairly level stretches of land adjoining stream beds. It is often broken by the mesquite-mountain ash-cottonwood association, the distri¬ bution of which follows the stream beds.
The soil is gravelly and usually light colored, but this association is occasionally found on the dark soil washed down from higher elevations to the stream beds and draws. The gravel is derived from both the Tascotal tuff and the Rawls basalt. *
Mesquite and the creosote bush are the most abundant plants, and their distribution is co-extensive. The vegetation of this association is dense and bushy. Other plants are catclaw, huisache, blackbrush, allthorn, lote- wood, senna, and the desert willow.
This association was trapped from June 7 to June 11, and from June 23 to June 26, 1952. More specimens were collected in this association than in any other association of the area, and the 42 specimens collected com¬ prised 34.4 per cent of the total prepared. The desert pocket-mouse ( Perog - nathus penicillatus ) was the most abundant species in this association and the most abundant small mammal in the area. Fourteen of the 2 5 kangaroo rats ( Dipodomys merriami) were collected in this association. The spotted ground squirrel ( Citellus spilosoma ) was seen and heard frequently in this association. Tracks of the ringtail ( Bassariscus astutus ) were seen by Mil- stead at a small spring near the ranch headquarters. Small bats which ap¬ peared to be canyon bats ( Pipistrellus hesperus ) were seen feeding at dusk over this association and over the mesquite-mountain ash-cottonwood as¬ sociation. A skull of the gray fox ( Urocyon cinereoar gen tens) was found in a mesquite bush by Milstead.
MESQUITE-MOUNTAIN ASH-COTTONWOOD ASSOCIATION
This association is found extensively throughout La Mota Rancho where stream beds and springs occur. The soil is very fine and quite sandy. It is light in color except where derived from the darker slopes or hills. In many places there is bare rock which is usually Rawls basalt, sometimes Tascotal tuff, and occasionally a light-colored sandstone.
The dominant plant is mesquite, but at the springs and on the more permanent stream beds there are towering mountain ash and large cotton¬ wood trees. At Colmano Spring, which is east of Los Fresnos in Caballo pasture, the cottonwood tree is second in importance, as it is along Torneros Creek, which runs through Alameda pasture. Here the creek banks are dense with cottonwoods, some a hundred feet in height, mountain ash, large mesquite trees, desert willows, and other minor plants that contribute to the underbrush.
At Los Fresnos, the ranch headquarters, and other springs, the moun¬ tain ash is second in importance. Along the dry creek beds are found mes¬ quite, blackbrush, and small mountain ash trees. The thorny hackberry was the fourth most abundant tree at Colmano Spring and at Los Fresnos.
1954, No. 1 March
Mammals of Trans-Pecos Texas
45
Other plants, in order of their abundance, are the desert willow, button willow (Cephalanthus Occident alls ) , catclaw, creosote bush, allthorn, senna, white brush ( Aloysia wrighti and A. ligustrina) , huisache, lotewood, and salt brush.
This association at Colmano Spring was trapped from June 17 to June 18, at Los Fresnos from June 26 to June 27, 1952. The bats taken in this association were the only bats collected in the area. Four pallid bats ( Antrozous pallidus ) were taken at night from the tool shed, and three canyon bats ( Pipistrellus hes perns) were collected by Milstead over a small pond near the ranch headquarters at dusk. The spotted ground squirrel ( Citellus spilosoma) and the desert pocket-mouse ( Perognathus penicillatus) were the other mammals taken in this association. The skull of a gray fox ( Urocyon cinereoargenteus) was found near the ranch headquarters, and two skulls of the hog-nosed skunk ( Conepatus mesoleucus) were also found in this association. The single record of the rock squirrel ( Citellus varie- gatus) from the area was obtained by Mr. A. I. Mills in the association along Torneros Creek in Alameda pasture. Mule deer ( Odocoileus hemionus) were often seen crossing dry creek beds or watering at various springs.
SUMAC-OAK ASSOCIATION
This small association was discovered by Milstead on his return to La Mota Rancho the week of July 29 to August 4, 1952. It is found about half-way up a small canyon on the north side of La Mota Mountain. The canyon floor is covered with humus and many boulders of Rawls basalt. The dominant vegetation includes sumac, Arizona oak ( Quercus arizonicus ) , Emory’s oak ( Quercus emoryi) , cherry plum ( Primus havardi) , and moun¬ tain ash. This association was not trapped.
Cactus was not found in this association, but six species of cacti were found to have about equal abundance in all the other associations. These six species are pitaya ( Echinocereus stamineus) , tasajillo ( Opuntia leptocaulis) , cholla ( Opuntia imbricata) , prickly pear ( Opuntia engelmanni) , purple tinge prickly pear ( Opuntia macrocentra ), and blind prickly pear ( Opuntia rufida) .
ANNOTATED LIST OF MAMMAL SPECIES
A total of 122 specimens representing 13 species were collected in the La Mota Mountain area, while 612 specimens of 18 species were collected in the Black Gap area. The small mammals were obtained by the use of small metal traps as described by Blair (1941). The larger mammals were taken with steel traps or by shooting. The information given by A. I. Mills of La Mota Rancho, Fred Moore of the Black Gap Wildlife Management Area, and other residents of the area is, in my opinion, valid. I have in¬ cluded information from Bailey (1905) concerning species which we did not collect but which have been recorded from these or proximal areas. The nomenclature, with subsequent revisions, is that of Miller (1924). The taxonomic classification of the mammals is that of Simpson (1945). All of the specimens collected are in the Texas Natural History Collection at the University of Texas.
Pipistrellus hes perns maximus Hatfield. Canyon Bat.
Bats of this species were seen flying as late as 7:30 a.m. and were active as early as 7:30 p.m. in the Black Gap area. The twenty specimens col¬ lected were for the most part taken over tanks or near water. Sixteen were
46
The Texas Journal of Science
1954, No. 1 March
collected over the Dell tank at the camp site in the persimmon-walnut as¬ sociation, and two were collected over the mesquite-huisache association. One was shot over a cliff association, and one was taken over the grama- prickly pear association. J. R. Barker discovered one of these small bats under a rock in the sotol-lechuguilla association. Dr. Blair informed me that it is not uncommon in western Texas to find these bats under rocks during the day time. This bat was the most common bat in the two areas studied and was the first to appear in the evening.
In the La Mota Mountain area, three canyon bats were collected in the mesquite-mountain ash-cottonwood association but were also seen over the mesquite-creosote bush association and the ocotillo-catclaw association. A. I. Mills reported that there were no bat caves on the ranch, but the extreme abundance of this species indicates the presence of caves in the region.
Bailey (1905) stated that this bat is usually the most common species where it occurs. This was found to be true in the Big Bend Park area by Borell and Bryant (1942), in the Sierra Vieja region by Blair and Miller (1949), and on the Stockton Plateau of Terrell County by Herrmann (1950).
Vlecotus rafinesqui pallescens (Miller). Long-eared Bat.
Sixteen were taken from a cave in a limestone bluff east of Black Gap and one-half mile from the Maravillas Creek road. All were females, and most of these were carrying young on the ventral surface of the body. The absence of males and the presence of young indicates that this female colony was a nesting colony. Several bats were knocked down while in flight by the use of sticks. No bats of this species were taken by shooting. Large bats were sometimes seen flying with the small canyon bats over tanks, but darkness prevented their collection. This bat was not found at La Mota Rancho.
Borell and Bryant (1942) found these bats in the numerous caves and abandoned mine shafts of the Big Bend Park area.
Antrozous pallidus pallidus (Le Conte). Pallid Bat.
Although not infrequently seen at La Mota, this bat was not as common as the canyon bat. Four specimens were taken with an insect net from the ranch tool shed, where they roosted at night, in the mesquite- mountain ash-cottonwood association. Individuals of this species were seen at dusk feeding over a tank in this association and were also observed over the mesquite-creosote bush association. One was seen in an abandoned mine shaft on the ranch. This large bat was not seen in the Black Gap area.
Bailey (1905) reported this species from various localities in south¬ western Texas. Five specimens were collected in the Big Bend Park area by Borell and Bryant (1942), but this bat was scarce in that area.
T ad arid a mexicana (Saussure). Mexican Freetail Bat.
One Mexican freetail bat was found in the limestone bat cave from which all the long-eared bats were taken. Ralph Axtell informed me that in the same limestone canyon he found a small cave in which approximately 2 5 freetail bats were clinging from crevices in the ceiling of the cave. No freetail bats were collected at La Mota Rancho.
Bailey (1905) found this bat to be one of the most common bats in western Texas. These bats were abundant along the river and foothills of
1954, No. 1 March
Mammals of Trans-Pecos Texas
47
the Big Bend Park area. Borell and Bryant (1942) found a colony of ap¬ proximately 3,000 on October 19, 1937, in a limestone cave high on the southeast slope of Mariscal Mountain.
Lepus calif ornicus texianus Waterhouse. Jack-rabbit.
Although the jackrabbit was one of the most common large mammals at La Mota Rancho, no specimens of this species were prepared. Two were shot in the ocotillo-catclaw association and were used for bait in trapping the carnivorous mammals. This species was seen in five of the seven asso¬ ciations found at La Mota Rancho and was abundant in each of these as¬ sociations. It was not seen in the lechuguilla-beargrass association on the summit of La Mota Mountain or in the rock bluff association.
In the Black Gap area, the jack-rabbit was fairly abundant and was seen in the mesquite-huisache, huisache-creosote, and sotol-lechuguilla as¬ sociations. One was taken in the persimmon-walnut association on June 30, 1951, by T. J. Cordray.
Borell and Bryant (1942) saw the jack-rabbit most frequently in brushy areas between 2,000 and 3,500 feet elevation in the Big Bend Park area.
Sylvilagus auduboni minor (Mearns). Desert Cottontail.
The single specimen obtained in the Black Gap area was trapped by Louis Follansbee in a steel trap set in an apparently abandoned badger burrow in the mesquite-huisache association. Several were seen in the sotol- lechuguilla and the grama-prickly pear associations but additional specimens were not collected.
At La Mota Rancho, this species was fairly common in the mesquite- creosote bush and the ocotillo-catclaw associations. On June 18, 1952, a specimen was collected by Milstead in the ocotillo-catclaw association. One was seen by Milstead on June 19, 1952, in the sotol-yucca-beargrass asso¬ ciation at the base of La Mota Mountain.
Bailey (1905) found this animal to be the common cottontail of west¬ ern Texas. Borell and Bryant (1942) found the desert cottontail to be com¬ mon in thickets of mesquite-catclaw, cactus, and creosote bush in the Big Bend Park area.
Citellus variegatus couchi (Baird). Rock Squirrel.
The rock squirrel was not collected in the La Mota Mountain area. On June 3, 1952, Milstead and I saw one on a limestone bluff at the west¬ ern edge of the Tascotal Mesa. On June 26, 1952, Mr. A. I. Mills saw a
rock squirrel cross Torneros Creek in Alameda pasture. Both of these squirrels were seen during the hottest part of the day. This animal is apparently rare in this area.
One was seen on June 16, 1951, by Louis Follansbee on a lava slope in the Black Gap area. This individual had a black head and mantle extend¬ ing back as far as the shoulder region. Dr. Blair saw an entirely black rock squirrel on a ridge of basalt near Black Gap. Selection for dark color may be operating in the same or similar manner with this squirrel as with the white- throated packrat ( Neotoma albigula) .
This species of squirrel was found to be one of the most conspicuous
animals in the Davis Mountains by Blair (1940) and in the Sierra Vieja
region by Blair and Miller (1949). In the Big Bend Park area, Borell and Bryant (1942) observed the rock squirrel about cliffs and rocky outcrops along the Rio Grande but found them to be far more abundant in rocky places among the pinons and junipers of the Chisos Mountains.
48
The Texas Journal of Science
1954, No. 1 March
Citellus interpret, (Merriam). Antelope Squirrel.
At La Mot a Rancho these squirrels are most common in the rock bluff association and in the ocotillo-catclaw association. Milstead reported seeing one in the sotol-yucca-beargrass association on La Mota Mountain. I saw one scamper approximately 20 feet up the dark rock bluff of La Mota Moun¬ tain. Three specimens of the antelope squirrel were collected by shooting. Two specimens were taken from the rock bluff association and one speci¬ men from the ocotillo-catclaw association. Several were discovered dead in live traps in the ocotillo-catclaw association when the traps were baited in the late afternoon. At La Mota Rancho they are active from mid-morning during the hottest part of the day to late afternoon. However, Herrmann (195 0) observed these squirrels to be active as early as 7:00 a.m. to as late as 7:00 p.m. In the ocotillo-catclaw association they are most common around the large boulders and rock outcrops. In the rock bluff association they range from the base to the top of the bluffs and are found on both the light and dark-colored rocks.
Eleven specimens of the antelope squirrel were collected at Black Gap. These were taken from rocky or nearly level terrain but were most fre¬ quently seen on lava talus slopes. One was collected from a lava ridge. Nine were taken from the sotol-lechuguilla association in rocky areas. An adult female was collected by T. E. Kennedy on December 29, 1951, in the grama-prickly pear association. They were frequently seen in the mes- quite-huisache association.
The specimens collected in the two areas are similar to specimens col¬ lected in Presidio County and Terrell County, Texas, and Pima County, Arizona.
Blair (1940) had no record of this squirrel from the Davis Mountains. Borell and Bryant (1942) saw the antelope squirrel most frequently in the higher canyons of the Big Bend Park area.
Citellus mexicanus parvidens (Mearns). Mexican Ground Squirrel.
No specimens of this ground squirrel were collected at La Mota Rancho. At the Black Gap Wildlife Management Area two specimens were taken in large wire traps. One was taken near a tank in the mesquite-huisache as¬ sociation. The other specimen was trapped in the persimmon-walnut asso¬ ciation. J. P. Brand and Louis Follansbee saw one among large lava boulders in the sotol-lechuguilla association.
This species was not found in the Sierra Vieja region by Blair and Miller (1949). Borell and Bryant (1942) have no record of this species in the Big Bend Park area. Taylor and Davis (1947) gave the distribution of this squirrel as southern and western Texas from the Balcones Escarpment, San Antonio, and Brownsville westward at least to the Davis Mountains.
Citellus spilosoma marginatus Bailey. Spotted Ground Squirrel.
This small, slender ground squirrel was the most abundant squirrel in the La Mota area. Eight specimens were collected by trapping with small live traps. Four specimens were taken from the mesquite-mountain ash- cottonwood association where the species was most abundant. Three speci¬ mens were taken from the mesquite-creosote bush association, and one was trapped in the creosote bush-ocotillo association, where they were less numer¬ ous. On several occasions this squirrel was found dead in small live traps, having perished from the heat during the day. In most instances they were
1954, No. 1 March
Mammals of Trans-Pecos Texas
49
seldom seen far from their burrows, which had as many as five entrances, usually at the base of a bushy shrub such as mesquite, catclaw, or creosote bush. More than one squirrel may occupy the same system of burrows, for as many as three squirrels were seen in the proximity of the same hole at one time. Like the antelope squirrel ( Citellus inter pres) , these wary squirrels are quite active during the hotter periods of the day. On warm days they were seen and heard from sunrise to sunset, and their presence was indicated by a high-pitched, shrill whistle which probably served as a warning device to other spotted ground squirrels.
This squirrel was not collected at Black Gap. Individuals were seen crossing the road ahead of the truck on several occasions. Attempts to trap them and dig them out of their burrows proved futile. Burrows were most frequently seen in gravelly soil in open or bare areas interspersed with creo¬ sote bush or huisache. One was seen by Dr. Blair in the yucca terrace asso¬ ciation.
The specimens collected from the La Mota Mountain area are somewhat dark, and the dorsal spotting is less distinct than in specimens from Dawson County and Hutchinson County, Texas, and Otero County, New Mexico.
This animal was not found in the Sierra Vieja region by Blair and Miller (1949) or on the Stockton Plateau by Herrmann (1950). In the Big Bend Park area, Borell and Bryant (1942) found it to be limited almost entirely to the desert flats between 2,200 and 4,000 feet elevation.
T homomys sp. Mountain Pocket Gopher.
Attempts to trap this pocket gopher in the Black Gap area were fruit¬ less. Burrows and mounds were easily located in thin soils at the lower edge of the limestone talus slopes in the lechuguilla-sotol association. The burrows and mounds are usually small, probably because the soil is extremely hard and rocky. Burrows could be located by looking for dead lechuguilla plants, but they were difficult to open sufficiently to set traps. Most burrows were firmly packed with earth which contained a high proportion of gopher droppings. An estimated 50-60 trap nights yielded not a single specimen.
No specimens of this genus were collected at La Mota. Numerous work¬ ings of this little gopher were seen in the sotol-yucca-beargrass and lechu- guilla-beargrass associations. A few mounds were seen in the creosote bush- ocotillo association, but in this association the mounds of the plains pocket gopher ( Cratogeomys cast an ops) were far more numerous. In the lechu- guilla-beargrass association on the summit of La Mota Mountain, mounds of this gopher were numerous in clumps of lechuguilla. In the sotol-yucca- beargrass association at the base and on the lower slopes of La Mota Moun¬ tain, their mounds were usually associated with sotol and yucca plants. This species was not recorded from the stream bed association (mesquite-moun- tain ash-cottonwood association), to which association Blair (1940) found this gopher restricted in the Davis Mountains.
In the Big Bend Park area, Borell and Bryant (1942) found these gophers to be widely distributed on the dry, rocky flats and lower slopes of the mountains.
Cratogeomys castanops lacrimalis Nelson and Goldman. Plains Pocket Gopher.
In the La Mota Mountain area, the plains pocket gopher is restricted to the creosote bush-ocotillo and the mesquite-mountain ash-cottonwood associations. In both associations numerous mounds were seen at the base
50
The Texas Journal of Science
1954, No. 1 March
of creosote and catclaw bushes. One specimen was collected from the cre¬ osote bush-ocotillo association. The mounds of the mountain pocket gopher ( Thomomys sp.) were also seen in the creosote bush-ocotillo association, but the mounds of this gopher were usually seen at the base of sotol or yucca plants. Mounds of the plains pocket gopher were quite common around the ranch house in the mesquite-mountain ash-cottonwood association. On the Stockton Plateau of Terrell County, Texas, Herrmann (1950) found that this gopher prefers leaves and stems of woody plants, while the moun¬ tain pocket gopher ( Thomomys sp.) lives primarily on roots.
This large pocket gopher could be found fairly easily in the deeper soils of the flood plains, terraces, and alluvial fans of the Black Gap area. In the region of the Dell tank this gopher was seen feeding in daylight on the roots and leaves of Bermuda grass growing on the downhill slope of the dam. A total of four specimens was prepared. Two were collected in gravel soil on the lower side toward the base of the tank. Two were taken from gravel soil in the mesquite-huisache association.
Borell and Bryant (1942) found the plains pocket gopher common along the Rio Grande in the sandy-loam river botton soil, and in only a few places in the Big Bend Park area did the ranges of the plains pocket gopher and the mountain pocket gopher overlap.
Perognathm merriami gilvus Osgood. Merriam Pocket-mouse.
This little pocket-mouse was taken in three associations in the La Mota Mountain area. Fifteen specimens of this species were prepared. Eleven of these were taken from the creosote-bush-ocotillo association, and three were trapped in the ocotillo-catclaw association. One was taken in the mesquite- creosote bush association. Two were found dead in live traps, and none were seen foraging at night. These fifteen specimens comprise 12.3 per cent of the 122 specimens collected.
At Black Gap, Perognafhtis merriami is common on the more upland slopes, and a total of 209 specimens was collected. These represent 34.1 per cent of the total collected in the area. Thirty-eight were trapped in the yucca terrace association. Twelve were taken in the persimmon-walnut as¬ sociation. Most (92) were found on the flood plains of the mesquite-huisache association. The rocky canyons and cliffs association yielded only nine speci¬ mens. Twenty-seven were trapped in the huisache-creosote bush association. Seventeen were taken from the sotol-lechuguilla association, and 14 were trapped in the grama-prickly pear association.
Although a high percentage was taken from areas with much lava rock, there does not seem to be any intensification of color on the lava. Al-Uthman (1952) found that there was no significant difference in pelage color between three samples of Perognathm merriami taken from the yucca terrace, mesquite flood plain, and lava rock of the Black Gap area. One population was living on the dark colored basalt of a lava flow, and the others were living on pale limestone soils. This failure of pelage color to correlate with the color of the basalt lava flow may be accounted for by the migration of lighter colored individuals from the limestone into the basalt lava areas, preventing the development of a dark-colored race on this lava. In his study of the Perognathus merriami occurring in three biotic provinces, Al-Uthman (op. cit.) found the Chihuahuan mice to be moderate sized, long tailed, and generally paler than those in the Kansan and the Tamauplipan biotic provinces.
1954, No. 1 March
Mammals of Trans-Pecos Texas
51
Only four specimens of the Merriam pocket-mouse were taken in the Big Bend Park area by Borell and Bryant (1942). These four were taken from a sandy flat at the north end of Mariscal Mountain.
Perognathus nelsoni collis Blair. Rock Pocket-mouse.
This species of pocket-mouse was most common in rocky, rough ter¬ rain in the Black Gap area. However, on flood plains and gentle slopes, this species and Perognathus merriami occurred together. Examination of speci¬ mens failed to show a significant difference in coloration between specimens from the limestone and specimens from the lava. Several individuals showed distinct moult lines and some appeared to lack even a single guard hair, thus presenting a rather curious appearance.
This pocket-mouse was probably the most abundant mammal in the Black Gap area, and a total of 2 50 (42.6 per cent of the total number of specimens obtained) was collected. These were recorded from all associations of the area (see Table II). They were quite abundant in the yucca terrace association, where 41 were trapped, and in the sotol-lechuguilla association, where 75 were taken. The grama-prickly pear association afforded the best habitat for this saxicolous form, and 96 specimens were obtained there.
At La Mota Rancho this pocket-mouse was relatively scarce. The 12 specimens taken in two associations comprised 9.8 per cent of the 122 speci¬ mens collected. Eleven were trapped in the ocotillo-catclaw association, and one was caught in the rock bluff association.
Evidently there is much fluctuation of population size in natural popu¬ lations of Perognathus nelsoni. The high population encountered at Black Gap and the high incidence of young and juveniles indicated that the popu¬ lation was at its peak. At La Mota juveniles or young of this species were not collected, but the low population encountered may have been a normal popu¬ lation in that area during the summer of 1952.
The rock pocket-mouse was not numerous but was taken by Borell and Bryant (1942) in several localities about the base of the Chisos Moun¬ tains from 2,300 and 4,800 feet elevations. Herrmann (1950) reported that only two specimens of this species were taken on the Stockton Plateau, and Blair and Miller (1949) found this species rather rare in the life belts of the Sierra Vieja region.
Perognathus penicillatus eremicus Mearns. Desert Pocket-mouse.
This species was found on low, sandy areas and flood plains in the two areas investigated. At Black Gap, this sparsely distributed species was repre¬ sented by 1 1 specimens. All but four of these were collected from flood plains in the yucca terrace association and the mesquite-huisache association. Additional specimens were obtained, but the delicate skins were ruined dur¬ ing the preparation by inexperienced students.
At La Mota this species is largely restricted to the mesquite-creosote bush association. Of the 122 specimens obtained, 31.1 per cent were speci¬ mens of this species, which was the most abundant of the 18 species col¬ lected. Eight were collected in the mesquite-mountain ash-cottonwood as¬ sociation, and six specimens were obtained in the ocotillo-catclaw and the creosote bush-ocotillo associations (see Table I).
In the Big Bend Park area and in the Sierra Vieja region, Borell and Bryant (1942) and Blair and Miller (1949) found this species to be limited to sandy soils and to be most abundant along the Rio Grande. Blair (1940)
52
The Texas Journal of Science
1954, No. 1 March
did not collect this species in the Davis Mountains, and Herrmann (1950) reported its absence from the Stockton Plateau of Terrell County, Texas.
Dipodomys merriami ambiguus Merriam. Four- toed Kangaroo Rat.
This was the second most common mammal in all the associations de¬ fined at La Mota, where it was exceeded in number only by Perognathus penicillatus. Twenty-five specimens of this small mammal were taken, and these specimens constituted 20.5 per cent of the 122 specimens taken. These rodents were most common in the mesquite-creosote bush association, where 14 specimens were collected. Five specimens were taken in the creosote bush- ocotillo association, and six specimens were trapped in the ocotillo-catclaw association.
Thirty-five specimens were collected in the Black Gap area. This was the only kangaroo rat found on the management area, and they were found on flood plains and more gentle slopes where the soil was sufficiently devel¬ oped to permit burrowing. One burrow was opened June 14, 1951, by Louis Follansbee, William Hightower, and Dr. Blair. This burrow was located on a mesquite flood plain at the base of a tasajillo bush. The depth of the tunnel floor beneath the surface varied from a few inches at the entrance to 16 inches at its greatest depth. The main tunnel was approximately four feet in length. There were two subsidiary branches from the main tunnel, one
of which was a short, blind tunnel about one foot from the entrance, and
the other was approximately three feet in length. Both the main tunnel and the large subsidiary tunnel terminated a few inches from the surface of the ground. The only evidence of Dipodomys merriami was the presence of re¬ cent droppings and fragments of vegetation along the floor of the tunnel. Two specimens of Cnemid o phorus tigris were driven from the burrow dur¬ ing the excavation.
At Black Gap, 3 1 specimens were collected on flood plains in the mes-
quite-huisache association. Three were found on a yucca flood plain in the
yucca terrace association, and one was taken from the sotol-lechuguilla as¬ sociation.
Specimens of Dipodomys merriami merriami in the Texas Natural His¬ tory Collection from areas near Valentine, Texas, were examined, and on comparison with specimens from La Mota and Black Gap were found to be much darker. Only four specimens, three from Black Gap and one from La Mota, approached the dull, dark coloration of the Valentine specimens. Likewise, specimens from the two areas were compared with specimens of Dipodomys merriami ambiguus from the Rio Grande Basin near Porvenir, Texas. Our specimens exhibit the same pale, bright coloration and are there¬ fore referred to the subspecies ambiguus as recognized by Blair (1949).
In the Big Bend Park area, Borell and Bryant (1942) found the kanga¬ roo rat common in the river bottom of the Rio Grande and in sandy areas up to 3,500 feet elevation.
Peromyscus eremicus eremicus (Baird). Cactus Mouse.
At Black Gap, the cactus mouse was taken in rocky situations with Perognathus nelsoni and Neoioma albigula. However, three were taken from a creosote bush flood plain in the mesquite-huisache association. This species seems to be rather sparsely distributed over the area (see Table II).
The cactus mouse was also rare at La Mota, and only seven specimens were obtained, all from rocky areas. Three were taken in the creosote bush- ocotillo association, and four were collected in the ocotillo-catclaw assoccia-
1954, No. 1 March
Mammals of Trans-Pecos Texas
53
tion. During our stay at La Mota Rancho, two were trapped in the ranch house by Mrs. A. I. Mills.
Blair and Miller (1949) found this mouse in the Sierra Vieja region, and Borell and Bryant (1942) found it to be the most common species of this genus in the Big Bend Park area. Herrmann (1950) did not find the cactus mouse on the Stockton Plateau, and only four specimens were col¬ lected by Blair (1940) in the Davis Mountains.
Peromyscus pectoralis laceianus Bailey. Encinal Mouse.
A total of eight specimens was collected in the two areas worked, and this species was the rarest of the small mammals in both localities. It can be distinguished from the similar Peromyscus eremicus by the small tail scales, the white tarsal joint without markings, and the lack of accessory cusps or enamel loops on the outer angles of the first and second molars.
Three were collected in the sotol-lechuguilla association and two in the mesquite-huisache association at Black Gap. One was collected in the lechuguilla-beargrass association and two in the rock bluff association at La Mota. This was the only mammal taken from any of the associations of La Mota Mountain.
This mouse has been collected by Blair (1940) in the Davis Mountains, by Herrmann (1950) on the Stockton Plateau of Terrell County, and by Borell and Bryant (1942) in the Big Bend Park area. However, as is the situation at La Mota and Black Gap, it was quite rare in these three areas. Blair and Miller (1949) found it to be the most common small mammal in the Roughland Belt of the Sierra Vieja region of Trans-Pecos Texas.
Neotoma albigula robtista Blair. White-throated Packrat.
This species of packrat is rare in the associations of the La Mota Moun¬ tain area, and only two were collected during the period spent there. These were young specimens trapped in small live traps in the ocotillo-catclaw as¬ sociation. The animals probably entered the traps during the day, for their dehydrated condition indicated that they had perished from the extreme heat. Old packrat signs were seen in the ocotillo-catclaw association, where rock outcrops and prickly pear cactus were plentiful.
Dr. Blair discovered nests of this species in cactus on lava slopes of the Black Gap area. Some specimens obtained from the lava were very dark, almost blue-black, in contrast to the gray pelage of those taken from the limestone. From the number of apparently abandoned nests, it would seem to indicate that the population was much higher in the immediate past. However, one specimen was obtained from a rather deep burrow which ap¬ peared quite old.
A total of 21 specimens was obtained in the Black Gap area, eight of which were of the light coloration. The first specimen was taken from the face of a limestone cliff one-half mile north of the camp site. Two were collected from rocky limestone, and the skin of one specimen was not saved. Two specimens were collected from the huisache-creosote bush association. One was collected from the yucca terrace association, and 16 were taken from the sotol-lechuguilla association. This unusual variability of coloration in Neotoma albigula will be discussed elsewhere in a paper by Dr. W. Frank Blair.
54
The Texas Journal of Science
1954, No. 1 March
A specimen of Neotoma albigula melas collected four miles west of Carrizozo, Lincoln County, New Mexico, exhibits a melanistic pelage similar to the Neotoma albigula taken from the lava of the Black Gap area. Other specimens in the Texas Natural History Collection from Randall, Lubbock, Cottle, and Armstrong counties, Texas, and from Otero and Lincoln coun¬ ties, New Mexico, have a lighter pelage coloration not unlike the specimens of the pale Neotoma albigula from Black Gap.
Bailey (1905) reported this species living side by side with Neotoma micropus in Presidio County. Four specimens were obtained by Borell and Bryant (1942) in the Chisos Mountains between 5,000 and 5,300 feet ele¬ vation.
Erethizon epixanthum Brandt. Yellow-haired Porcupine.
No specimens of this species were collected at La Mota Rancho or at the Black Gap Wildlife Management Area. However, A. I. Mills informed me that two porcupines were seen on La Mota Rancho in 1950.
Taylor and Davis (1947) reported that porcupines have been observed in Brewster and Jeff Davis Counties, but that they are seldom seen even where common. This animal was not found in the Big Bend Park area by Borell and Bryant (1942) or on the Stockton Plateau of Terrell County, Texas, by Herrmann (1950).
Canis latrans texensis Bailey. Coyote.
No coyotes were seen in the La Mota Mountain area. A. I. Mills in¬ formed me that coyotes have been seen on the ranch, but these animals have been kept under control because of their menace to sheep. On the Rawls Ranch, which adjoins La Mota Rancho to the north and to the east, a coyote was seen the week of July 1, 1952.
Fred Moore trapped 18 coyotes during 1949-1950 at Black Gap but reports that coyotes are rare there at present. None was seen or taken by our field party.
Borell and Bryant (1942) found the coyote to be fairly common from the river bottom up to 5,000 feet elevation in the Chisos Mountains.
Vulpes macrotis neomexicanus Merraim. New Mexico Desert Fox.
Fred Moore informed us that this fox was more abundant in previous years than at present at Black Gap but that an occasional "big-eared” fox is seen near the refuge headquarters. None were taken by our field party.
Bailey (1905) found this fox to be uncommon in Trans-Pecos Texas. However, the ranchers may have never distinguished it from the common and much larger, darker-colored fox of the genus Urocyon. There is no record of this animal from La Mota Rancho, and it was not found by Blair (1940) in the Davis Mountains or by Blair and Miller (1949) in the Sierra Vieja region. Borell and Bryant (1942) had no record of this species from the Big Bend Park area.
Urocyon cinereoargenteus scottii Mearns. Gray Fox.
Fred Moore reported the gray fox to be rather scarce on the Black Gap Wildlife Management Area. Like the big-eared fox, its population appears to have decreased in the last few years. This animal was not seen by any of our field party. The gray fox was uncommon at La Mota Rancho. One skull was found in the mesquite-mountain ash-cottonwood association, and another was found in the mesquite-creosote bush association.
1954, No. 1 March
Mammals of Trans-Pecos Texas
55
Borell and Bryant (1942) found the gray fox scarce in the Big Bend Park area.
Ursus americanus amblyceps Baird. Black Bear.
Fred Moore reports bear signs are seen infrequently in the Black Gap area. A geology graduate student saw a young black bear south of Mara¬ thon, Texas, during the summer of 1950. As this bear was viewed at close range, there was no mistaken identification. There are no records of this animal from La Mota Rancho.
Bailey (1905) recorded this bear from Onion Creek, 30 miles south of Marfa, and found it common in the Davis Mountains. Borell and Bryant (1942) found the black bear to be fairly common in the higher parts of the Chisos Mountains.
Bassariscus as tutus flavus Rhoads. Ringtail.
In the Black Gap area, two specimens of the ringtail were obtained by using steel traps set in the lava rimrock. Scats seen at the base of lime¬ stone cliffs were tentatively identified by Louis Follansbee as those of this animal. Only one specimen of this species was prepared.
During our stay at La Mota Rancho, ringtails were not seen, but A. I. Mills informed me that he has seen the animals and their tracks on a floodplain north of the air strip in the mesquite-mountain ash-cottonwood association. Milstead saw several tracks at a small spring one-fourth mile west of the ranch headquarters in the mesquite-creosote bush association. Mrs. A. I. Mills told me that for a number of years after the ranch house was first occupied ringtails inhabited the attic and raised their kits there.
Borell and Bryant (1942) found the ringtail to be the most abundant fur bearer in the Big Bend Park area.
Taxidea taxus berlandieri Baird. Badger.
No badgers were taken by our field party at Black Gap. Burrows sup¬ posedly made by badgers were seen occasionally in the deeper alluvial soils. Fred Moore reported that his dogs have chased badgers into their burrows and that an occasional badger is seen in the day time near the headquarters of the management area.
No badgers were seen in the La Mota Mountain area. A. I. Mills saw an animal of this description on the eastern slopes of La Mota Mountain but said that it has not been seen in recent years.
The occurrence of the badger has been recorded from various locali¬ ties in Trans-Pecos Texas. Borell and Bryant (1942) found the badger to be widely distributed in the Big Bend Park area but not common.
Mephitis macrotira milleri Mearns. Flooded Skunk.
The only specimen of this species obtained in the Black Gap area was an adult female taken from an abandoned adobe hut in the mesquite-huisache association by T. E. Kennerly on December 3 0, 195 1. A. I. Mills has not seen this species in the La Mota Mountain area, and none were seen by us in that area during the summer of 1952.
Blair (1940) collected one specimen of this species near Mount Liver¬ more in the Davis Mountains, and Blair and Miller (1949) found it to be the rarest skunk of the Sierra Vieja region. It was not collected by Borell and Bryant (1942) in the Big Bend Park area or by Herrmann (1950) on the Stockton Plateau of Terrell County, Texas.
56
The Texas Journal of Science
1954, No. 1 March
Spilogale gracilis leucoparia Merriam. Little Spotted Skunk.
In the Black Gap area, a spotted skunk was collected at night as it crossed a stream bed in the persimmon-walnut association. It was placed in a wooden box with a window-screen cover. At noon the following day it was observed for several minutes. Sometime in the early mid-afternoon it escaped by prying the screen cover loose. Fred Moore informed us that this species is seen quite frequently on the flood plain near the headquarters of the area. This skunk was not recorded from the La Mota Mountain area.
Borell and Bryant (1942) have reports of the spotted skunk from vari¬ ous localities between the Rio Grande and the highest parts of the Chisos Mountains, but at the time of writing it was apparently rare.
Conepatus mesoleucus mearnsi Merriam. Hog-nosed Skunk.
No specimens of the hog-nosed skunk were collected in the La Mota Mountain area. Two skulls were found in the mesquite-mountain ash-cotton¬ wood association. One was found a short distance south of the ranch head¬ quarters. The other was found near the spring at Colmano. A. I. Mills in¬ formed us that "civet-cats” and skunks have been quite common on the ranch in the past. In many places their presence was indicated by small ex¬ cavations near the bases of brushy trees, sotol, and lechuguilla. On the night of June 16, 1952, Milstead and I saw a skunk of this species on the Presidio highway just before entering the ranch road.
One hog-nosed skunk was collected by Dr. Blair on July 10, 1951, at the crossing of Javalina Creek northeast of our camp site in the Black Gap area. Fred Moore informed us that on occasional hog-nosed skunk is seen at night near the headquarters of the area.
Borell and Bryant (1942) found the diggings of hog-nosed skunks in grassy areas and along the banks of the Rio Grande in the Chisos Moun¬ tains area.
Felis rufiis baileyi (Merriam). Bobcat.
The week before our arrival at La Mota Rancho a bobcat was killed in the ocotillo-catclaw association by one of the ranch hands. A. I. Mills has occasionally killed a bobcat on the ranch in the last few years. The mountain lion ( Felis concolor) and the bobcat have been kept effectively under control by the sheep ranchers of the region. However, on the ad¬ joining ranch, the Rawls Ranch, twelve bobcats had been killed during the first few months of 1952.
At Black Gap occasional signs were seen along creek bottoms. Signs consisted primarily of scats and tracks. None was collected or seen by our field party.
Bailey (1905) had a record of this animal from the head of Onion Creek, Presidio County, Texas. Borell and Bryant (1942) found the bob¬ cat to be fairly common and widely distributed from the Rio Grande up to at least 5,500 feet elevation in the Big Bend Park area.
Felis concolor stanleyana Goldman. Mountain Lion.
Due to control measures, this species at present does not occur on La Mota Rancho. The last record of a mountain lion in the area was one killed on Torneros Creek in 1946 by A. I. Mills. However, from 1941 to 1946, according to Mr. Mills, 14 mountain lions were killed, and seven of those were killed in Panther Canyon, a small canyon four miles west of the ranch headquarters. No specimens of this species were collected.
1954, No. 1 March
Mammals of Trans-Pecos Texas
57
Fred Moore informed us that an occasional transient mountain lion is killed on the Black Gap Wildlife Management Area. Signs were seen in a limestone canyon on June 19, 1951, by members of the field party, and Fred Moore discovered a freshly killed domestic goat at the entrance to the large limestone bat cave.
In spite of control measures, the mountain lion is still present in many Trans-Pecos localities. Borell and Bryant (1942) found mountain lions to be fairly numerous in the higher parts of the Chisos Mountains and to range occasionally through the adjoining hills and onto the inter-mountain flats of the Big Bend Park area. Their continued presence in these areas can be explained by the proximity of the mountainous area of Mexico, where they are still common today.
T ay asm tajacu (Linnaeus). Javelina.
Although this species was not seen at La Mota Rancho, A. I. Mills reported that the javelina is not uncommon. Possibly due to the absence of the coyote, the javelina has extended its range into the La Mota Mountain area in recent years. Ranchers in this area find that if one species is present in an area, the other is absent.
There was ample evidence of the presence of the javelina in the Black Gap area. However, these animals were not easily located. Members of the field trip came upon a group of eight (five sows, two pigs, and one boar) on Maravillas Creek. Fred Moore had two skulls of this species at the man¬ agement headquarters.
Bailey (1905) did not find this species in Presidio County. Herrmann (1950) reported that two specimens were collected with steel traps on the Stockton Plateau of Terrell County. Blair and Miller (1949) reported that individuals were seen in the Sierra Vieja region. Borell and Bryant (1942) found the javalina confined to a comparatively small portion of the Big Bend Park area, mainly the flats and slopes surrounding the northern end of the Chisos Mountains.
Odocoileus hemionus crooki (Mearns). Mule Deer.
Mule deer are not uncommon at La Mota Rancho. On June 3, 1952, two mule deer were seen on the southwest slope of La Mota Mountain in the sotol-yucca-beargrass association. They were also seen in the ocotillo- catclaw, creosote bush-ocotillo, and mesquite-mountain ash-cottonwood as¬ sociations. One complete skeleton and parts of skeletons were seen in various associations throughout the ranch. A. I. Mills informed us that the extended drought has resulted in the death of many mule deer. In his study of the mule deer of the Sierra Vieja region, Anderson (1949) states that surface or free water apparently is not required by mule deer. However, on June 5, 1952, a young mule deer was seen drinking with several sheep at a small spring southeast of the ranch headquarters, and Mrs. A. I. Mills said that it is not uncommon in the winter months to see several deer come for water in the late afternoon at the small spring back of the ranch house.
Mule deer are native to the Black Gap area, but their numbers had so declined due to hunting and overgrazing by sheep, goats, and cattle, that the Texas Game and Fish Commission had recently released over 600 ani¬ mals in the area. Two were found dead, and singles and groups of as many as five were seen by members of the field party. Mule deer were seen in five of the seven associations of the area.
58
The Texas Journal of Science
1954, No. 1 March
Bailey (1905) found the mule deer to be more or less common in the barren foothills and out-lying desert ranges at long distances from any known source of water in the Trans-Pecos Texas area. Borell and Bryant (1942) found the main population of the mule deer in the lower foothills of the Chisos Mountains. This is the most important game animal in Trans- Pecos Texas.
FAUNAL RELATIONSHIPS OF THE TWO AREAS INVESTIGATED
The Black Gap Wildlife Management Area and the La Mota Moun¬ tain area lie in the southern part of the Chihuahuan biotic province of Texas, and the mammalian fauna encountered indicates that these two areas are typical of this biotic province. Blair (1950) stated that 83 species of mammals have been recorded in recent times from the Chihuahuan biotic province. Thirty-two species were recorded from the two areas under con¬ sideration. The 18 species characteristic of the Chihuahuan biotic province that are recorded from the Black Gap and La Mota areas comprise 56.3 per cent of the total number of species.
The mammalian faunas of the Black Gap area and of the La Mota Mountain area are not unlike the faunas of other Trans-Pecos areas that have been studied. Although both areas are geographically close to the Big Bend Park area, the variety of habitats, the differences in vegetation, and the heavier rainfall allow for a greater diversity in the fauna of the Park area. Of the 5 5 species recorded from that area, 30 (54.5 per cent) were found in the Black Gap and La Mota areas. Only three species, Mephitis macroura, Vulpes macrotis, and Citellus mexicanus , were not recorded from the Park by Borell and Bryant (1942) that were recorded from the two areas under consideration.
Thirty-one (66.1 per cent) of the species recorded from the Black Gap and La Mota areas were ones that had been reported from the Rough- land and Plains Life Belts of the Sierra Vieja region by Blair and Miller (1949). Two species, Citellus spilosoma and Citellus mexicanus , which have not been reported from that area, were found in the Black Gap and La Mota areas.
Twenty-eight (50.9 per cent) of the 55 species recorded in the Davis Mountains by Blair (1940) were present at Black Gap and La Mota. Plecotus rafinesqui, Vulpes macrotis , and Tayassu tajacu were not recorded from the Davis Mountains.
In comparing the fauna of the two areas studied, six species (18.8 per cent of the total recorded from both areas) found at Black Gap were not found in the La Mota Mountain area. These six species were: Plecotus rafin¬ esqui, T adarida mexicana, Spilogale gracilis, Mephitis macroura , Citellus mexicanus, and Tayassu tajacu. Two (6.3 per cent) of the species collected at La Mota were not obtained in the Black Gap area. These species were Antrozous pallidus and Urocyon cinereorgenteus. In both areas there was an abundance of small mammals and a scarcity of the larger predatory mam¬ mals. Previous to our stay at La Mota, an extended drought had reduced the abundance of food-producing vegetation, and this may explain the scarcity of such species as Perognathus merriami and Perognathus nelsoni, both of which were abundant in the Black Gap area the previous summer. However, as populations of small mammals are subject to abrupt popula¬ tion changes, these two species may have been more abundant in previous
1954, No. 1 March
Mammals of Trans-Pecos Texas
59
years, and likewise the population of these species at Black Gap during the summer of 1952 may have been much less than that recorded in the summer of 1951. Perognathus nelsoni and Neotoma albigula, both saxicolous forms, were abundant in the rocky areas of Black Gap during the summer of 1951; and the scarcity of Neotoma albigula in the La Mota Mountain area, which affords ample rock rabitats and Opuntia in which to nest, might be explained by a decline in the normal population or by the resistance of the animal to trapping methods employed.
Perognathus penicillatus, which was the most abundant mammal in the La Mota Mountain area, was scarce at Black Gap during the summer of 1951. Competition between this species and Perognathus nelsoni may have caused its relative scarcity in the area. However, the number of specimens of Perognathus penicillatus recorded from Black Gap is not an accurate representation of the sampling of the population present, for numerous skins of this species were destroyed during preparation.
Antrozous pallidus , which was found only at La Mota, was not col¬ lected at Black Gap but may have been in that area. Likewise, Plecotus rafinesqui and Tad arid a mexicana were not recorded from La Mota. Large bats were often seen in both areas, and these and other species might have been taken if collecting had been intensified.
In both areas the small rodent population was extremely high, while populations of the predator species, on the other hand, were low. The cause of this unbalanced condition was not determined. At La Mota only signs and remains of the carnivorous mammals indicated their presence. At Black Gap few sight records were obtained for the predator species. Felis rufus was quite abundant in areas proximal to La Mota, but only one record for this species was obtained at Black Gap. T ayassu ta)acu was recorded only from Black Gap, but the period of drought, heavy grazing by livestock, and competition for food with other large mammals may account for its ab¬ sence at La Mota.
The major ecological difference between the Black Gap and La Mota areas and the Davis and Chisos Mountains is in elevation. The maximum elevation in the Davis Mountains is 8,3 82 feet, and the Chisos Mountains have a maximum elevation of 7,83 5 feet. The highest point in the Black Gap area is 5,000 feet, and La Mota Mountain reaches a height of 5,046 feet. Because of the absence of favorable climatic conditions and of several resultant ecological associations, many species of vertebrates found in the higher mountains are not found at Black Gap or La Mota. A comparable situation holds for the Sierra Vieja region, where the highest elevation is 6,467 feet, the rainfall less, and the mountains warmer than those of the higher elevations of the Davis or Chisos Mountains.
SUMMARY
The ecological distribution of the mammals of the Black Gap Wild¬ life Management Area, Brewster County, Texas, was studied from June 7 to July 12, and from December 28 to December 31, 1951. The mammals of the La Mota Mountain area, Presidio County, Texas, were studied from June 3 to July 4, 1952. The mammalian fauna of each of these two areas is characteristic of low or moderate elevations in the Chihuahuan biotic province.
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1954, No. 1 March
In the La Mota Mountain area, eight ecological associations were de¬ scribed. Seven ecological associations were described in the Black Gap Wild¬ life Management Area.
A total of 122 specimens representing 13 species was collected in the La Mota Mountain area, and 612 specimens representing 18 species were collected in the Black Gap area.
Comparison of the mammalian fauna of the Black Gap and La Mota Mountain areas with that of the Davis Mountains, as described by Blair (1940), and the Chisos Mountains, as described by Borell and Bryant (1942), indicate that the mammalian fauna of the areas studied is small because of the absence of species normally restricted to life belts at higher elevations in the mountains of Trans-Pecos Texas.
ACKNOWLEDGEMENTS
This study was undertaken at the suggestion of Dr. W. Frank Blair, to whom I am particularly grateful. I wish to thank Dr. B. Warnock of Sul Ross State College for his identification of the plants collected at La Mota Rancho and Dr. B. C. Tharp for reading the manuscript and for his helpful suggestions during its preparation. To Mr. and Mrs. A. I. Mills, owners of La Mota Rancho, I wish to express my appreciation for their hospitality, friendship, and interest in our work during our stay there. To Fred Moore, manager of the Black Gap Wildlife Management Area, I am grateful for his assistance to our field party during our stay in the area. I am deeply indebted to W. W. Milstead for his great help in collecting the mammal specimens and for his companionship during our stay at La Mota. W. L. Thompson supplied invaluable data from his own work in the Black Gap area, and R. W. Axtell furnished the map of the Big Bend area.
LITERATURE CITED
Al-Uthman, H. S. — 1952 — Geographic variation in the Merriam pocket mouse ( Perognathus merriam ) in three biotic provinces in Texas. Unpubl. M. A. thesis, Univ. Texas.
ANDERSON, W. A. — 1949 — Early summer foods and movements of the mule deer ( Odocoileus hemionus) in the Sierra Vieja Range of southwestern Texas. Tex. Jour. Sci. 1(4) : 45-50.
AXTELL, R. W. — Amphibians and reptiles of the Black Gap Wildlife Management Area, Brewster County, Texas. Unpublished.
BAILEY, Vernon — 1905 — Biological survey of Texas. North Amer. Fauna 25:1-222.
Blair, W. Frank — 1940 — A contribution to the ecology and faunal relationships of the mammals of the Davis Mountains region, southwestern Texas. Misc. Publ. Univ. Mich. Mus. Zool. 45: 1-39
- 1941 — A simple and effective live trap for small mammals. Jour. Wildlife
Management 5 : 1 9 1 - 1 9 3 -
- 1949 — Shade of pelage color in two populations of kangaroo rats and remarks
on the status of Dipodomys merriami ambiguus Merriam. Jour. Mammalogy 30 (4) : 388-390.
- 1950 — The biotic provinces of Texas. Tex. Jour. Sci. 2(1): 93-117.
- and C. E. Miller — 1949 — The mammals of the Sierra Vieja region, south¬ western Texas, with remarks on the biogeographic position of the region. Tex. Jour. Sci. 1 (1) : 67-92.
Borell, A. E. and M. D. Bryant — 1942 — Mammals of the Big Bend area of Texas. Univ. Calif. Publ. Zool. 48: 1-62.
1954, No. 1 March
Mammals of Trans-Pecos Texas
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DAVIS, W. B. — 1940 — Mammals of the Guadalupe Mountains of western Texas. Occas. Pap. Mus. Zoo/. La. State Univ. 7 : 69-84.
- and J. L. Robinson, Jr.— 1944 — The mammals of Culberson County, Texas.
Jour. Mammalogy 25 * 254-273.
DICE, L. R. — 1943 — The biotic provinces of North America. Univ. Mich. Press, Ann Arbor.
ERICKSON, Ralph L. — 1951 — Stratigraphy and petrology of the Tascotal Mesa Quad- range, Texas. Unpub. Ph. D. thesis, Univ. Minn.
HERRMANN, J. A. — 1950 — The mammals of the Stockton Plateau of northeastern Terrell County, Texas. Tex. Jour. Sci. 2 (3) : 368-393.
MILLER, G. S., Jr. — 1924 — List of North American recent mammals. U. S. Nat. Mus. Bull. 128: 1-673.
MlLSTEAD, W. W. — Ecological distribution of the lizards of the La Mota Mountain region of Trans-Pecos Texas. Tex. Jour. Sci. (in press).
SIMPSON, G. G. — 1945 — The principles of classification and a classification of mam¬ mals. Bull. Am. Mus. Nat. Hist. 85: 1-350.
TAYLOR, W. P. and W. B. Davis — 1947 — The mammals of Texas. Game, Fish and Oyster Comm. Bull. 27: 1-79.
Tharp, B. C. — 1939 — The vegetation of Texas. Tex. Acad. Sci. Publ. Nat. Hist., Non¬ tech. Ser. 1 : 1-74.
THOMPSON, W. L. — 1953 — The ecological distribution of the birds of the Black Gap area, Brewster County, Texas. Tex. Jour. Sci. 5 (2) : 158-177.
THORNTHWAITE, C. W. — 1948 — An approach toward a rational classification of climate. Georgr. Rev. 38: 55-94.
Weaver, J. E. and F. E. Clements — 1948 — Plant ecology, 2nd ed. McGraw Hill.
WILSON, Duncan C. — 1951 — Stratigraphy of the Black Gap area, Brewster County, Texas. Unpubl. M. A. thesis, Univ. Texas.
Yearbook of Agriculture — 1941 — Climate and man. U. S. Dept. Agriculture, Washington, D. C.
COMPARATIVE NOTES ON SOUTHWESTERN INDIAN MEDICAL PRACTICES*
CHARLES H. LANGE The University of Texas
In his paper, "On the Collecting of Data Concerning Primitive Medi¬ cine,” Ackerknecht (1945: 427-430) reviewed the fluctuations of anthro¬ pological interests in the study of primitive medicine. In brief, he noted that observations of the sixteenth and seventeenth centuries were devoted to learning the "tricks” of these non-Europeans. Since the treatments in¬ volved overt magico-religious elements and included such common pro¬ cedures as bloodletting, purges, emetics, and plant or animal drugs, there was no reason to notice, let alone emphasize, any basic differences between their own practices and principles and those of the primitives. He further noted that late in the nineteenth century, with the development of chemi¬ cals and later synthetic drugs, Western medicine reevaluated the medical practices of primitives as quackery. This belief was perhaps strengthened, Ackerknecht indicated, by the fact that anthropological leaders of that period had, in several instances (A. Bastian, P. Ehrenreich, W. Matthews, et al.) , experienced medical training themselves.
In conjunction with the overall improvement of ethnographic tech¬ niques during the last twenty-five years, Ackerknecht noted a similar im¬ provement in the study of primitive medicine. His observations, comparing not only primitive medicine but aspects of our own practices as well, will not be recapitulated at any greater length here. Certain of his remarks have been taken as a base from which to briefly survey various aspects of medi¬ cal practices among the Indian tribes of the American Southwest.
In examining the literature on these tribes, it is readily apparent that medicine men, shamans, or "witch doctors,” whatever their popular desig¬ nation may be, generally occupy positions of honor and high prestige within their own cultures. Occasionally they are regarded with equally high esteem and/or awe among people of neighboring cultures (see White, 1942: 320). An attempt will be made to indicate how warranted the prestige accorded these medicine men and the faith placed in their knowledge and abilities actually are.
Among the Southwestern tribes, shamans of the Yuman and Uto- Aztecan speaking desert tribes perform as individuals (Bennett and Zingg, 193 5: 252-267; Joseph, Spicer, and Chesky, 1949: 72-80; Spier, 1933: 280- 290). The same pattern is typical of the Upland Yumans (Gifford, 1936: 307-317; McKennan, 193 5: 185-188; Spier, 1928: 275-285) and of the Apache (Bourke, 1892; Opler, 1941: 216-315) and Navaho (Wyman, 193 6). While several practitioners may occasionally combine their knowl¬ edge and skill in a particular case, there are no organized medicine societies such as those found in the various Pueblo tribes (Cushing, 1920: 133;
* Excerpts from this paper were presented at the 1933 annual meeting of the Texas Academy of Science, Galveston, Texas, December 3-5, 1953.
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Southwestern Medical Practices
63
Parsons, 1925; Parsons, 1939; Stevenson, 1890, 1904; White, 1942; and others). Of the Pueblo societies, those of the Keresans are