UTAH THE I DESERT TORTOISE COUNCIL ARIZONA NEVADA I I I / '~ ' / ry( C F ~ ~$ ~7,­ • ~ gf ( -f fpi i i)xX , = .-. .=:.=-;-,. (= - ' ( (j 1 7 ,))gp / r= / / SVM t & % p wc a 4 CA LIFO R NI A PROCEEDINGS OF 1993 SYMPOSIUM DESERT TORTOISE COUNCIL PROCEEDINGS OF 1993 SYMPOSIUM A compilation of reports and papers presented at the 18th annual symposium Publications of the Desert Tortoise Council, Inc. Proceedings of the 1976 Desert Tortoise Council Symposium $15.00 Proceedings of the 1977 Desert Tortoise Council Symposium $15.00 Proceedings of the 1978 Desert Tortoise Council Symposium $15.00 Proceedings of the 1979 Desert Tortoise Council Symposium $15.00 Proceedings of the 1980 Desert Tortoise Council Symposium $15.00 Proceedings of the 1981 Desert Tortoise Council Symposium $15.00 Proceedings of the 1982 Desert Tortoise Council Symposium $15.00 Proceedings of the 1983 Desert Tortoise Council Symposium $15.00 Proceedings of the 1984 Desert Tortoise Council Symposium $15.00 Proceedings of the 1985 Desert Tortoise Council Symposium $15.00 Proceedings of the 1986 Desert Tortoise Council Symposium $15.00 Proceedings of the 1987-91 Desert Tortoise Council Symposium $15.00 Proceedings of the 1992 Desert Tortoise Council Symposium $15.00 Proceedings of the 1993 Desert Tortoise Council Symposium $15.00 Annotated Bibliography of the Desert Tortoise, Gopherus agassizii $15.00 Note: Please add $1.50 per copy to cover postage and handling. Foreign addresses add $3.50 per copy for surface mail. U. S. Drafts only. Available from: Desert Tortoise Council, Inc. P. O. Box 1738 Palm Desert, CA 92261-1738 These proceedings record the papers presented at the annual symposium of the Desert Tortoise Council. The Council, however, does not necessarily endorses the conclusions reached in the papers, nor can it attest to the validity or accuracy of the data. Copyright © 1996 by the Desert Tortoise Council, Inc. ISSN 0191-3875 All rights reserved. No part of this book may be used or reproduced in any form or by any means, or stored in a database or retrieval system, without prior written permission of the publisher. Making copies of any part of this book for any purpose other than your own personal use is a violation of United States copyright laws. Printed in the United States of America. THE DESERT TORTOISE COUNCIL The Desert Tortoise Council is a private, nonprofit organization made up of hundreds of professionals and lay-persons from all walks of life, from across the United States, and on several continents. The goal of the Desert Tortoise Council is: To assure the perpetual survival of viable populations of the desert tortoise within suitable areas of its historic range. The objectives of the Desert Tortoise Council are: a. To serve in a professional advisory manner, where appropriate, on matters involving management, conservation, and protection of desert tortoises. b. To support such measures as will contribute to ensuring the continued survival of desert tortoises and the maintenance of their habitat in a natural state. c. To stimulate and encourage studies on the ecology, biology, management, and protection of desert tortoises. d. To serve as a clearinghouse of information among all agencies, organizations, and individuals engaged in work on desert tortoises. e. To disseminate current infor mation by publishing proceedings and transactions of meetings and other papers as deemed appropriate. f. To maintain an active public information and conservation education program. g. To commend outstanding action and dedication by individuals and organizations promoting the objectives of the Council. DESERT TORTOISE COUNCIL BOARD OF DiRECTORS Offic~ Senior Co-Chairperson: Mare Graff, M.D. Co-Chairperson: Tom Dodson Co-Chairperson-elect: Bob Turner Recording Secretary: Ed LaRue Secretary: Terrie Correll Treasurer: Mike Coffeen Boar M mbers Kristin Berry, Ph.D. Jay Slack Ted Cordery Glenn Stewart, Ph.D. Mare Sazaki Editorial C mmittee Editor: Kirstine M. Thorne Cover Design: Suzanne Allan TABLE OF CONTENTS (Program abstracts included for papers published elsewhere or manuscripts not submitted by Proceedings deadline. Ed.) ANNUAL AWARD NUTRITION AND FORAGING ECOLOGY Interactions of Range Cattle and Desert Tortoises at Ivanpah Valley, California: 1993 Field Observations Harold W. Avery and Alexander G. Neibergs Nutritional Ecology of the Desert Tortoise Consuming Native Versus Exotic Desert Plants Harold W. Avery A Comparison of the Plant and Rodent Communities Inside toThose Outside the Desert Tortoise Natural Area, Kern County, California Matthew L. Brooks Foraging and Diet Selection in Desert Tortoises: Annual Update on Research in the Northeast Mojave Desert of Arizona and Utah T. C. Esque, L. A. DeFalco, and C. R. Tracy Foraging Ecology of the Desert Tortoise (Gopherus agassizii) in the 14 Western Mojave Desert, California W. Bryan Jennings Nutritional Constraints Associated with Desert Plants in the Eastern Mojave 15 O. T. Oftedal, P. S. Barboza, D. E. Ullrey, M. E. Allen, J. C. Keene, and D. L. Freitas Foraging Ecology of Sonoran Desert Tortoises, 1992 Annual Report 16 John R. Snider Preliminary Study of Desert Tortoise (Xerobates agassizii) Diet in the 17 Northeastern Sonoran Desert Thomas R. Van Devende, Howard E. Lawler, and Elizabeth Wirt Sapium biloculare (Mexican Jumping Bean) as a Probable Cause of 18 Mortality for Gopherus agassizii (Desert Tortoise) in the Maricopa Mountains, Maricopa Co., Arizona Elizabeth B. Wirt SOCIAL INTERACTIONS, POPULATION TRENDS, AND REPRODUCTION Winter Sheltersite Use in a Sonoran Desert Tortoise Population 21 Scott J. Bailey, Cecil R. Schwalbe, and Charles H. Lowe The Goffs Population Model Revisited: New Data and New Models 22 Kristin Berry, Michael Weinstein, Fred Turner, David Randall, and Gary White Burrow Use by Desert Tortoises, (Gopherus agassizii): Social Factors 23 Susan Bulova Social Interactions of Desert Tortoises at Two Sites in the Northeast 26 Mojave Desert L. A. DeFalco and T. C. Esque Demographis of Three Desert Tortoise Populations in the 27 Sonoran Desert Scott Hart A Summary of Sonoran Desert Tortoise Population Monitoring in Arizona 37 J. M. Howland and A. P. Woodman A 25-year Study of Three-toed Box Turtle Population Dynamics 38 Ross Kiester Status and Exploitation of the Pancake Tortoise (Malococherus tornieri) in Tanzania Michael W. Klemens Statistical Validity and Desert Tortoise Density Estimates: The Problems of 41 100% Sampling and Statistical Power Anthony J. Krzysik Methods for Monitoring Sonoran Populations of the Desert Tortoise 42 Roy C. Murray and Cecil R. Schwalbe Role of Male-Male Interaction and Female Choice in the Mating System of 43 the Desert Tortoise Hope A. Niblick, David Rostal, and Thomas Classen The Desert Tortoise: Adapted Xerophile or Tenuous Relic Charles C. Peterson Seasonal Reproductive Cycle of the Desert Tortoise (Gopherus agassizii) 45 in the Eastern Mojave Desert David C. Rostal, Valentine A. Lance, Janice S. Grumbles, and Allison C. Alberts Non-lethal Sexing Techniques for Hatchling and Immature Desert Tortoises 46 (Gopherus agassizii) David C. Rostal, Janice S. Grumbles, Valentine A. Lance, and James R. Spotila A Behavioral Inventory of the Desert Tortoise: Development of an Ethogram 47 Douglas E.Ruby and Hope A. Niblick Effects of Incubation Conditions on Sex Determination, Hatching Success, and 48 Growth of Hatchling Desert Tortoises (Gopherus agassizii) James R. Spotila, L. C. Zimmerman, Christopher A. Binkley, David C. Rostal, Albert List jr., Janice Grumbles, Eva C. Beyer, Kelly M. Phillips, and Stanley J. Kemp Comparisons of Size Class Structures, Growth Rates, and Recruitment of 49 Sonoran and Mojave Desert Tortoises A. P. Woodman and J. M. Howland UPPER RESPIRATORY TRACT DISEASE AND HEALTH PROFILES Niycoplasma agassizii Causes Upper Respiratory Tract Disease in the 50 Desert Tortoise, A Threatened Species Mary B. Brown, Isabella M. Schumacher, Paul A. Klein, Terrie Correll, and Elliott R. Jacobson Laboratory Health Profiles of Free-Ranging Desert Tortoises in 51 California: Evaluation of Physiologic and Pathologic Alterations M. M. Christopher, K. A. Nagy, I. R. Wallis, B. T. Henen, C. C. Peterson, J. K. Klaassen, and K. H. Berry Evaluation of Bone Marrow from Desert Tortoises(Gopherus agassizii) 53 Michael Garner, Bruce Homer, Elliott Jacobson, Rose Raskin, Betty J. Hall, and Wayne A. Weis Variations in Upper Respiratory Tract Disease at the Desert Tortoise 55 Conservation Center, Las Vegas, Nevada: Occurrence, Hematologic and Biochemical Parameters Janice S. Grumbles, Linda C. Zimmerman, David C. Rostal, Robert H. George, and Michael O' Connor Transmission Studies with Upper Respiratory Tract Disease of the 56 Desert Tortoise: Setting Up the Experimental Challenge Groups Elliott R. Jacobson, Terrie Correll, Virginia Skinner, Jean Voshall, Mary B. Brown, Paul A. Kline, Isabella Schumacher, and Bobby R. Collins Hematological and Biochemical Indicators of Stress in Free-ranging 57 Desert Tortoises and Captive Tortoises Exposed to a Hydric Stress Gradient Michael P. O' Connor, Janice Grumbles, Robert H. George, Linda C. Zimmerman, and James R. Spotila Mycoplasma agassizii - Specific Antibodies in Desert Tortoises from 58 Desert Tortoise Natural Area, Goffs, and Ivanpah Isabella Schumacher, Mary B. Brown, Elliott R. Jacobson, Kristin Berry, Brian Henen, Kenneth Nagy, lan Wallls, and Paul A. Klein Health, Physiology and Mortality in Desert Tortoises in California 59 from 1989 to 1991 I. R. Wallis, K. A. Nagy, B. S. Wilson, B. T. Henen, C. C. Peterson, C. Meienberger, and I. A. Girard Mortality Rates and Health of Sonoran Desert Tortoises 60 A. P. Woodman and J. M. Howland Thermoregulation by Desert Tortoises in the Eastern Mojave Desert: 61 Seasonal Patterns of Operative and Body Temperatures, and Microhabitat Utilization L. C. Zimmerman, M. P. O' Connor, S, Bulova, J. R. Spotila, S. Kemp, and G. Salice CONSERVATION AND MANAGEMENT Desert Tortoise Abundance and Quantitative Measures of Human Use in 62 the Rand Mountains, Freemont Valley, and Spangler Hills Kristin Berry, Michael Weinstein, Gilbert Goodlett, Glenn Goodlett, and A. Peter Woodman Tortoise Behavior: Highways, Fences, and Preserve Design 64 William I. Boarman, Mare Sazaki, Gilbert C.