Systematics of the Colubrid Snake Lamproneltis triangulum Lacepede A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Zoology by Kenneth L. Williams B.S., University of Illinois, 1959 M.S., University of Illinois, 1961 August, 1970 ACKNOWLEDGEMENTS I wish to thank Dr. Douglas A. Rossman, my major professor, for his aid and encouragement during this study. I also wish to thaiik the other members of my advisory committee, Drs. Nell B. Causey, William G. Haag, Walter J. Harman, George H. Lowery, Jr., and J. P. Woodring. This study would have been completely impossible without the aid of the following individuals who loaned me specimens and/or provided me with other information: Walter Auffenberg, Ralph W. Axtell, Joseph R. Bailey, Roger W. Barbour, George T. Baxter, th Albert P. Blair, Richard A. Blake, Richard M. Blaney, Charles M. Bogert, James E. Bohlke, Herbert T. Boschung, Ronald A. Brandon, Donald R. Brothers, Bryce C. Brown, Richard C. Bruce, Janalee P. Caldwell, Charles C. Carpenter, Robert F. Clarke, Joseph T. Collins, Roger Conant, Francis R. Cook, Joseph F. Copp, Bill J. Davis, William G. Degenhardt, John Dickerson, W. E. Dickinson, James R. Dixon, Charles L. Douglas, Neil H. Douglas, William E. Duellman, Mike Duever, Harold A, Dundee, D. G. Dunlap, J. Eiselt, Carl H. Ernest, Denzel E. Ferguson, George W. Foley, Thomas Fritts, Charles M. Fugler, Bryan P. Glass, Stanley W. Gorham, Kenneth L. Gosner, A. G. C. Grandison, Jean Guibe, Harvey L. Gunderson, Donald E. Hahn, Dale Hein, Willard L. Henning, Donald F. Hoffmeister, J. Alan Holman, James E. Huheey, Robert F. Inger, J. Knox Jones, Edmond D. Keiser, Chesley A. Ketchersid, James D. Lazell, John M. Legler, Alan E. Leviton, Ernest A. Liner, James C. List, John D. lynch, Clarency J. McCoy, William N. McFarland, Clark R. Mahrdt, Edmond V. Malnate, Robert F. Martin, Hymen Marx, Sam P. Marynick, T. Paul Maslin, Robert Mertens, John R. Meyer, Sherman A. Minton, Robert H. Mount, Max A. Nickerson, R. Earl Olson, Michael M. Ovchynnyk, William W. Palmer, James A. Peters, Douglas A. Rossman, Gerald G. Schaefer, Jay M. Savage, Norman J. Scott, Henri C. Seibert, Allan J. Sloan, Dorthy Smith, Hobart M. Smith, Philip W. Smith, A. F. Stimson, David H. Snyder, Wilmer W. Tanner, Hariy Taylor, Donald W. Tinkle, Frank Toby, Menico Torchio, Keith D. Uhl, Thomas Uzzell, James M. Walker, Harland D. Walley, Robert G. Webb, Ernest E. Williams, Gaiy M. Williamson, Larry D. Wilson, Gaston-Francois de Witte, John W. Wright, Harry C. Yeatman, and Richard G- Zweifel, During my tenure at Northwestern State University I have been aided constantly by Tommy Hardaway, and during certain semesters by Mike Parry, Bill Elisey, Clyde Fisher, Carol Scarpinato, Hilbert Hall, Crittie Mae Roberson, and Mary Margaret Bailes. Mike Fistoreus has aided with the numerous photographic aspects of this study. Dianne Fisher aided in several French translations. Earle A. Cross, Bobby R. Waldron, and Thomas A. Burns aided at various times by providing me with information on statistics or by advising me on the use of the computer. Dr. Bums has also read portions of the text, and offered numerous helpful suggestions. William G. Erwin has been especially understanding and helpful during the period that I have worked in his Department. I am grateful to Philip W. Smith for providing me with data on a number of Illinois specimens. Lariy D. Wilson supplied data on the John Dickerson collection (Honduras), as well as color notes and a number of specimens; he also prepared two of the illustrations. In addition he spent many hours discussing with me the numerous problems encountered in this study, and in reading the first draft of the dissertation, for which I owe him a great deal of thanks. My wife, Viola, has aided in the preparation of most of the illustrations. Special thanks are due Hobart M. Smith for his constant aid in finding Mexican localities and in providing me with literature otherwise unavailable. Richard G. Zweifel and Charles M. Eogert kindly granted me permission to use the outlines of the head illustrations of Lampropeltis triangulum presented in Bogert and.Oliver (1945). I wish to acknowledge a Sigma Xi Research Grant awarded to me in June, 19^6, which has supported a portion of this research. I will not attempt to express in words my thanks to my wife, but instead note that this volume is dedicated to her, and to our daughters, Michele, Christine, and Kimberly. To anyone who has been overlooked in this list of acknowl­ edgements, I apologize. The conclusions and interpretations presented in this study are not necessarily those of the individuals acknowledged. ABSTRACT The taxonomy and distribution of lampropeltis triangulum Lacepede are discussed. The variation exhibited by the various characters studied is summarized and analyzed for possible sexual, ontogenetic, geographic, and individual significance. A discussion of head and body pattern is included in each subspecies account. Available information on distribution, natural history, and habitat preference are discussed for each subspecies. Nineteen subspecies were recognized prior to this study. Two of these subspecies are not retained: schmidti is placed in the synonymy of nelsoni. and temporalis is considered to be an intergrade population between triangulum and elapsoides. Six addition subspecies are described as new: smithi. conanti, sinaloae, hondurensis. stuarti, and andesiana. The fossil history is summarized. The intraspecific relation­ ships are discussed. TABLE OF CONTENTS PAGE INTRODUCTION........................................... 1 MATERIAIS AND METHODS........................... .. 2 HISTORICAL REVIEW................................ 7 DESCRIPTION OF THE SPECIES. ......................... 16 DISTRIBUTION........................ 17 VARIATION.............................................. 23 HEAD SCUTELLATION.................................. 23 BODY SCUTELLATION.................................. 39 SIZE AND PROPORTIONS............................... 60 PATTERN........................................... 68 HEMIPENIS...... 80 DENTITION.......................................... 80 CRITERIA FOR SUBSPECIES IDENTIFICATION.................. 87 KEY TO THE SUBSPECIES OF LAMPROPELTIS TRIANGULUM .... 92 SUBSPECIES ACCOUNTS.................... 98 LAMPROPEIUS TRIANGULUM TRIANGULUM................. 98 LAMPROPELTIS TRIANGULUM ELAPSOIDES................. 119 LAMPROPELTIS TRIANGULUM SYSPILA.................... 144 LAMPROPELTIS TRIANGULUM GENTILIS................... 159 LAMPROPELTIS TRIANGULUM MULTISTRATA................ 168 LAMPROPELTIS TRIANGULUM TAYLORI.................... 177 LAMPROPELTIS TRIANGULUM CELAENOPS.................. 185 LAMPROPELTIS TRIANGULUM AMAURA..................... 193 Y PAGE LAMPROPELTIS TRIANGULUM AM U LATA................... 206 LAMPROPELTIS TRIANGULUM POLYZONA................... 215 LAMPROPELTIS TRIANGULUM SMITHI subsp. nov........... 224 LAMPROPELTIS TRIANGUIUM SINALOAE subsp. nov......... 235 LAMPROPELTIS TRIANGULUM NELSONI.................... 243 LAMPROPELTIS TRIANGULUM AROIEERA................... 254 LAMPROPELTIS TRIANGULUM CONANTI subsp. nov.......... 268 LAMPROPELTIS TRIANGULUM OILGOZONA.................. 277 LAMPROPELTIS TRIANGULUM BLANCHARDI................. 285 LAMPROPELTIS TRIANGUIUM ABNORMA.................... 292 LAMPROPELTIS TRIANGUIUM HONDURENSIS subsp. nov...... 301 LAMPROPELTIS TRIANGULUM STUARTI subsp. nov.......... 308 LAMPROPELTIS TRIANGUIUM GAIGEAE.................... 316 LAMPROPELTIS TRIANGULUM MICROPHOLIS............. 323 LAMPROPELTIS TRIANGUIUM ANDESIANA subsp. nov........ 330 FOSSIL HISTORY.......................................... 340 CONCLUSIONS............................................ 342 LITERATURE CITED........................................ 348 VITA....... 370 vi LIST OF TABLES Number Page 1. Variation in number of supralabials in Lampropeltis triangulum......................................... 24 _2. -Variation in number of infralabials in Lampropeltis triangulum......................................... 26 3* Variation in number of preoculars in Lampropeltis triangulum. ....................................... 30 4. Variation in number of postoculars in Lampropeltis triangulum......................................... 32 5. Variation in number of loreals in Lampropeltis triangulum......................................... 35 6. Variation in number of temporals in Lampropeltis triangulum......................................... 37 7. Sexual dimorphism in ventral number of Lampropeltis triangulum......................................... 41 S. Sexual dimorphism in subcaudal number of Lampropeltis triangulum............................. 48 9. Individual, sexual, and geographic variation in numbers of dorsal scale rows in Tampropeltis triangulum......................................... 58 10. Sexual variation in number of dorsal scale rows just anterior to vent in Lampropeltis triangulum.......... 59 11. Variation in total length of Lampropeltis triangulum.. 62 12. Sexual dimorphism in relative tail length of Lampropeltis triangulum............ 66 1 3 . Head pattern types in Lampropeltis triangulum........ 71 1 4. Variation in red body rings or blotches of lampropeltis triangulum......................... 81 15. Food records for lampropeltis triangulum triangulum... 107 16. Reproductive data for Tamnroneltis triangulum triangulum........................................