University of Kansas Publications Museum of Natural History Volume 11, No. 10, pp. 527-669, 16 pis., 29 figs. March?, 1960 Natural History of the Ornate Box Turtle, Terrapene ornata ornata Agassiz BY JOHN M. LEGLER University of Kansas Lawrence 1960 University of Kansas Publications, Museum of Natural History Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Robert W. Wilson Volume 11, No. 10, pp. 527-669, 16 pis., 29 figs. Published March 7, 1960 University of Kansas Lawrence, Kansas MUS. CQMP. ZOOL LIBRARY MAR 2 4 1960 PRINTED IN THE STATE PRJNTING PLANT TOPEKA. KANSAS IS60 28-773 Natural History of the Ornate Box Turtle, Terrapene ornata ornata Agassiz BY John M. Legler CONTENTS PAGE Introduction 531 Acknowledgments 531 Systematic Relationships and Distribution 532 Fossils 534 Economic Importance 534 Study Areas 535 Materials and Methods 537 Terminology 539 Habitat and Limiting Factors 539 Habitat in Kansas 542 Reproduction 543 Mating 543 Insemination 545 Sexual Cycle of Males 545 Sexual Cycle of Females 549 Nesting 554 Eggs 558 Embryonic Development 560 Fertility and Prenatal Mortahty 564 Reproductive Potential 565 Number of Reproductive Years 565 Growth and Development 565 Initiation of Growth 565 Size and Appearance at Hatching 566 Growtli of Epidermal Laminae 568 Growth of Juveniles 575 Growth in Later Life 578 Annual Period of Growth 580 Environmental Factors Influencing Growth 580 Number of Growing Years 584 Longevity 585 Weight 586 (529) 530 University of Kansas Publs., Mus. Nat. Hist. PACE Bony Shell 586 Color and Markings 593 Wear 595 Sexual Dimorphism 596 Temperature Relationships 598 Optimum Temperature 599 Basking 600 Toleration of Thermal Maxima and Minima 601 Hibernation 611 Diet 617 Populations 623 Movements 626 Locomotion 627 Daily Cycle of Activity 629 Seasonal Cycle of Activity 630 Home Range 632 Homing Behavior 636 Social Relationships 637 Injuries 638 Repair of Injuries to the Shell 641 Ectoparasites 643 Predators 646 Defence 648 Discussion of Adaptations 650 Summary 656 Literature cited 663 Natural History of the Ornate Box Turtle 531. INTRODUCTION The ornate box turtle, Terrapene o. ornata Agassiz, was studied more or less continuously from September, 1953, until July, 1957. Intensive field studies were made of free-living, marked populations in two small areas of Douglas County, Kansas, in the period 1954 to 1956. Laboratory studies were made, whenever possible, of phe- nomena diflBcult to observe in the field, or to clarify or substantiate field observations. Certain of the phases work ( for example, studies of and populations movements ) were based almost entirely on field observation whereas other phases (for example, growth and game- togenic cycles) were carried out almost entirely within the labora- tory on specimens obtained from eastern Kansas and other localities. A taxonomic revision of the genus Terrapene was begun in 1956 as an outgrowth of the present study. The systematic status of T. ornata and other species is here discussed only briefly. Objectives of the study here reported on were: 1) to learn as much as possible concerning the habits, adaptations, and life history of T. o. ornata; 2) to compare the information tlius acquired with corresponding information on other emyid and testudinid chelo- nians, and especially with that on other species and subspecies of Terrapene; 3) to determine what factors hmit the geographic distribution of ornate box turtles; and, 4) to determine the role of ornate box turtles in an ecological community. Acknowledgments The aid given by a number of persons has contributed substantially to the present study. I am grateful to my wife. Avis J. Legler, who, more than any single person, has unselfishly contributed her time to this project; in addition to making all the liistological preparations and typing the entire manuscript, she has assisted and encouraged me in every phase of the study. Dr. Henry S. Fitch has been most helpful in offering counsel and encouragement. Thanks are due Professor E. Raymond Hall for critically reading the manuscript. Special thanks are due also to the following persons: Professor A. B. Leonard for helpful suggestions dealing with photography and for advice on several parts of the manuscript; Professor William C. Young for the use of facihties at the Endocrine Laboratory, University of Kansas; Professor Edward H. Taylor for permission to study specimens in his care; Dr. Richard B. Loomis for identifying chigger mites and offering helpful suggestions on tlie discussion of ectoparasites; Mr. Irwin Ungar for identification of plants; and, Mr. Wilham R. Brecheisen for allowing me to examine his field notes and for assistance with field work. Identifications of animal remains in stomachs were made by Pro- fessor A. B. Leonard (moUusks, crustaceans), Dr. George W. Byers (arthro- pods), and Dr. Sydney Anderson (mammals). Miss Sophia Damm generously permitted the use of her property as a study area and Mr. Walter W. Wulfkuhle made available two saddle horses that 532 University of Kansas Publs., Mus. Nat. Hist. greatly facilitated field work. The drawings (with the exception of Fig. 21) are by Miss Lucy Jean Remple. All photographs are by the author. I am grateftJ also to the Kansas Academy of Science for three research grants (totaUng $175.00) that supported part of the work. The brief dis- cussion of taxonomic relationships and distribution results partly from studies made by means of two research grants (totaling $150.00), from the Graduate School, University of Kansas, for which I thank Dean John H. Nelson. Systematic Relationships and Distribution Turtles of the genus Terrapene belong to the Emyidae, a family com- prising chiefly aquatic and semiaquatic species. Terrapene, nevertheless, is adapted for terrestrial existence and di£Fers from all other North American emyids in having a hinged and movable plastron and a down-turned (although often notched) maxillary beak. Emydoidea blandingi, the only other North American emyid with a hinged plastron, lacks a down-turned beak. The adaptations of box turtles to terrestrial existence (reduction of webbing be- tween toes, reduction in number of phalanges, reduction of zygomatic arch, and heightening of shell) occur in far greater degree in true land tortoises of the family Testudinidae. Four genera of emyid turtles in the eastern hemisphere (Cuora, Cyclemys, Emtjs, and Notochelys) possess terrestrial adap- tations paralleling those of Terrapene but (with the possible exception of Cuora) the adaptations are less pronounced than in Terrapene. A movable plastron has occurred independently in two groups of emyids in the New World and in at least three groups in the Old World. The genus Terrapene, in my view, contains seven species, comprising 11 named kinds. Of these species, five are poorly known and occur only in Mexico. Terrapene mexicana (northeastern Mexico) and T. yucatana (Yu- catan peninsula) although closely related, diflFer from each other in a number of characters. Similarly, Terrapene klauberi (southern Sonora) and T. nehoni (Tepic, Nayarit—known from a single adult male) are closely related but are considered distinct because of their morphological differences and widely separated known ranges. Terrapene coahuila, so far found only in the basin of Cuatro Cienegas in central Coahuila, is the most primitive Terrapene known; it differs from other box turtles in a number of morphological characters and is the only member of the genus that is chiefly aquatic. Two species of Terrapene occur in the United States. Terrapene Carolina, having four recognized subspecies, has a nearly continuous distribution from iouthom Maine, southern Michigan, and southern Wisconsin, southward to Florida and the Gulf coast and westward to southeastern Kansas, eastern Oklahoma and eastern Texas, and characteristically inhabits wooded areas. Terrapene omata is a characteristic inhabitant of the western prairies of the United States, and ranges from western and southern Illinois, Missouri, Oklahoma, and all but the extreme eastern part of Texas, westward to south- eastern Wyoming, eastern Colorado, eastern and southern New Mexico, and southern Arizona, and, from southern South Dakota and southern Wisconsin, southward to northern Mexico (Fig. 1). It is the only species of tlie genus that occurs in both Mexico and the United States. The northeastemmost populations of T. omata, occurring in small areas of prairie in Indiana and Illinois, seem to be isolated from the main range of the species. The ranges of T. omata and T. Carolina overlap in the broad belt of prairie-forest ecotone in the central United States. Interspecific matings under laboratory conditions Natural History of the Ornate Box Turtle 533 are not uncommon and several verbal reports of such matings under natural conditions have reached me. Nevertheless, after examining many specimens of both species and all alleged "hybrids" recorded in the literature, I find no convincing evidence that hybridization occurs under natural conditions. Terrapene ornata differs from T. Carolina in having a low, flattened carapace lacking a middorsal keel (carapace highly arched and distinctly keeled in Carolina), and in having four claw^s on the hind foot (three or four in Carolina), the claw of the first toe of males being widened, thickened, and turned in (first toe not thus modified in Carolina). Terrapene ornata is here considered to be the most specialized member of the genus by virtue of its reduced pha- langeal formula, hghtened, relatively loosely articulated shell, reduced plastron, and hghtly built skull, which completely lacks quadratojugal bones (Fig. 2); most of these specializations seem to be associated with adaptation for terrestrial existence in open habitats. scale of miles Fig. 1. Geographic distribution of Terrapene ornata. Sohd symbols indicate the known range of T. o. ornata and hollow symbols the known range of T. 0. luteola. Half-circles show the approximate range of intergradation be- tween the two subspecies. Triangles indicate locahties recorded in Uterature; specimens were examined from all other localities shown. Only peripheral locahties are shown on the map.