Natural History of the Ornate Box Turtle, Terrapene ornata ornata Agassiz

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Terrapene ornata ornata Agassiz, by John M. Legler

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Title: Natural History of the Ornate Box Turtle, Terrapene ornata ornata Agassiz

Author: John M. Legler

Release Date: September 29, 2011 [EBook #37566]

Language: English

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University of Kansas Publications

Museum of Natural History

Volume 11, No. 10, pp. 527-669, 16 pls., 29 figs.

  March 7, 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 pls., 29 figs.

Published March 7, 1960

University of Kansas

Lawrence, Kansas

PRINTED IN

THE STATE PRINTING PLANT

TOPEKA, KANSAS

1960

28-773

Natural History of the Ornate Box Turtle, Terrapene ornata ornata Agassiz

BY

John M. Legler

CONTENTS

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 phenomena difficult to observe in the field, or to clarify or substantiate field observations. Certain phases of the work (for example, studies of populations and movements) were based almost entirely on field observation whereas other phases (for example, growth and gametogenic cycles) were carried out almost entirely within the laboratory 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 thus acquired with corresponding information on other emyid and testudinid chelonians, and especially with that on other species and subspecies of Terrapene; 3) to determine what factors limit 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 histological 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 facilities 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 the discussion of ectoparasites; Mr. Irwin Ungar for identification of plants; and, Mr. William 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 Professor A. B. Leonard (mollusks, crustaceans), Dr. George W. Byers (arthropods), 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 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 grateful also to the Kansas Academy of Science for three research grants (totaling $175.00) that supported part of the work. The brief discussion 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 comprising chiefly aquatic and semiaquatic species. Terrapene, nevertheless, is adapted for terrestrial existence and differs 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 between 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, Emys, and Notochelys) possess terrestrial adaptations 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 (Yucatan peninsula) although closely related, differ from each other in a number of characters. Similarly, Terrapene klauberi (southern Sonora) and T. nelsoni (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 Ciénegas 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 southern 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 ornata 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 southeastern 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 the genus that occurs in both Mexico and the United States. The northeasternmost populations of T. ornata, 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. ornata and T. carolina overlap in the broad belt of prairie-forest ecotone in the central United States. Interspecific matings under laboratory conditions 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 claws 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 phalangeal formula, lightened, relatively loosely articulated shell, reduced plastron, and lightly 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.

Fig. 1.

Geographic distribution of Terrapene ornata. Solid symbols indicate the known range of T. o. ornata and hollow symbols the known range of T. o. luteola. Half-circles show the approximate range of intergradation between the two subspecies. Triangles indicate localities recorded in literature; specimens were examined from all other localities shown. Only peripheral localities are shown on the map.

Two subspecies of T. ornata an recognized. Terrapene o. luteola, Smith and Ramsey (1952), ranges from northern Sonora (Guaymas) and southern Arizona (southern Pima County) eastward to southeastern New Mexico and Trans-Pecos, Texas, where it intergrades with T. o. ornata; the latter subspecies is not yet known from Mexico but almost surely occurs in the northeastern part of that country. The subspecies luteola differs from ornata in being slightly larger and in having more pale radiations on the shell (11 to 14 radiations on the second lateral lamina in luteola, five to eight in ornata). In individuals of luteola the markings of the shell become less distinct with advancing age and eventually are lost; shells of most old individuals are uniform straw color or pale greenish-brown; this change in coloration does not occur in T. o. ornata.

Fig. 2.

Dorsal and lateral views of skull of T. o. ornata (a and b) (KU 1172, male, from 6 ml. S. Garnett, Anderson Co., Kansas) and of T. carolina (c and d) (KU 39742, from northern Florida). Note the relatively higher brain-case and the incomplete zygomatic arch in T. o. ornata. All figures natural size.

Fossils

Of the several species of fossil Terrapene described (Hay, 1908b:359-367, Auffenberg, 1958), most are clearly allied to Recent T. carolina. One species, Terrapene longinsulae Hay, (1908a:166-168, Pl. 26) from … the Upper Miocene or Lower Pliocene…. of Phillips County, Kansas, however, is closely related to T. ornata (if not identical). I have examined the type specimen of T. longinsulae. Stock and Bode (1936:234, Pl. 8) reported T. ornata from sub-Recent deposits near Clovis, Curry County, New Mexico.

Economic Importance

Ornate box turtles, referred to as land terrapins or land tortoises over most of the range of the species, are regarded by most persons whom I have queried as innocuous. These turtles occasionally damage garden crops and have been known to eat the eggs of upland game birds. Terrapene ornata is seldom used for food. A. B. Leonard told me the species was eaten occasionally by Arapaho Indians in Dewey County, Oklahoma. Several specimens in the University of Kansas Archeological Collections were found in Indian middens in Rice County, Kansas, from a culture dated approximately 1500 to 1600

A. D.

The flesh of T. ornata occasionally may be toxic if the turtle has eaten toxic fungi as has been recorded for T. carolina (Carr, 1952:147).

Study Areas

Preliminary studies and collections of specimens were made at a number of localities in northeastern Kansas in 1953 and 1954. Two small areas were finally selected for more intensive study. One of these areas, the University of Kansas Natural History Reservation, five and one-half miles north-northeast of Lawrence in the northeasternmost section of Douglas County, Kansas, is a tract of 590 acres maintained as a natural area for biological investigations. Slightly less than two thirds (338 acres) of the Reservation is wooded; the remainder consists of open areas having vegetation ranging from undisturbed prairie grassland to weedy, partly brushy fields (Fitch, 1952). Although ornate box turtles were not numerous at the Reservation, the area was selected for study because: 1) there was a minimum of interference there from man and none from domestic animals; 2) the vegetation of the Reservation is typical of areas where T. ornata and T. carolina occur sympatrically (actually only one specimen of T. carolina has been seen at the Reservation); and, 3) availability of biological and climatological data there greatly facilitated the present study. Actual field work at the Reservation consisted of studies of hibernation and long-term observations on movements of a few box turtles.

A much larger number of individuals was intensively studied on a tract of land, owned by Sophia Damm, situated 12 miles west and one and one-half miles north of Lawrence in the northwestern quarter of Douglas County, Kansas. The Damm Farm lies on the southern slope of a prominence—extending northwestward from Lawrence to Topeka—that separates the Kansas River Valley from the watershed of the Wakarusa River to the south. The prominence has an elevation of approximately 1100 feet and is dissected on both sides by small valleys draining into the two larger river valleys.

The Damm Farm (see Pl. 15) has a total area of approximately 220 acres. The crest of a hill extends diagonally from the middle of the northern edge approximately two thirds of the distance to the southwestern corner. Another hill is in the extreme northwestern corner of the study area.

The northeastern 22 acres were wooded and had small patches of overgrazed pasture. Trees in the wooded area were Black Walnut (Juglans nigra), Elms (Ulmus americana, U. rubra), Cottonwood (Populus deltoides), and Northern Prickly Ash (Xanthoxylum americanum). The areas used as pasture had thick growths of Buckbush (Symphoricarpos orbiculatus) mixed with short grasses (Bromus japonicus, Muhlenbergia Schreberi, and Poa pratensis). Farm buildings were situated in the wooded area at the end of an entry road. The southeastern 74 acres were cultivated; corn, wheat, and milo were grown here and fallow fields had a sparse growth of weeds.

Most of the western two thirds of the study area, comprising 124 acres, was open rolling prairie (hereafter referred to as pasture) upon which beef-cattle were grazed (Pl. 16, Fig. 1; Pl. 17, Fig. 1; Pl. 18, Fig. 2). Rock fences (Pl. 17, Fig. 2) two to four feet high bordered the northern edge, southern edge, and one half of western edge of the pasture. A wagon track lead from a gate on the entry road, along the crest of the hill, to a gate in the southern fence. Except for the latter gate and for ocassional under-cut places in low areas, there were no openings in the rock fences through which box turtles could pass. A few trees—American Elm, Hackberry (Celtis occidentalis), Red Mulberry (Morus rubra), Osage Orange (Maclura pomifera), Black Cherry (Prunus serotina), Box-Elder (Acer Negundo), and Dogwood (Cornus Drummondi)—were scattered along fences at the borders of the pasture and in ravines. Larger trees in a small wooded creek-bed at the southwestern edge of the pasture were chiefly Cottonwood, American Elm, Red Mulberry, and Black Willow (Salix nigra). The only trees growing on the pasture itself were a few small Osage Orange, none of which bore fruit.

Paths were worn along fences by cattle and in several places near the fence, usually beneath shade trees, there were large bare places where cattle congregated. Vegetation near paths and bare places was weedy and in some places there were tall stands of Smooth Sumac (Rhus glabra).

Rich stands of prairie grasses occurred along the top of the hill in the pasture; bluestems (Andropogon gerardi, A. scoparius) were the dominant species and Switchgrass (Panicum virgatum) and Indian grass (Sorghastrum nutans) were scattered throughout. A number of small areas on top of the hill were moderately overgrazed, as indicated by mixture of native grasses with an association of shorter plants consisting chiefly of Ragweed (Ambrosia artemisiifolia var. elatior), Mugwort (Artemisia ludoviciana), Japanese Chess (Bromus japonicus), and Asters (Aster sp.).

The upper parts of the hillsides were overgrazed moderately to heavily. Limestone rocks of various sizes were partly embedded in soil or lay loose at the surface. Depressions beneath rocks provided shelter for box turtles as well as for other small vertebrates. Native grasses were sparse in this area and gave way to Sideoats Grama (Bouteloua curtipendula), extensive patches of Smooth Sumac, and scattered colonies of Buckbrush.

Tall grasses were dominant on the lower hillsides and small patches of Slough grass (Spartina pectinata) grew in moist areas. Ravines originated at small intermittent springs on the sides of the hill. The banks of ravines were high and steep and more or less bare of vegetation. High, dense stands of Slough grass grew at intermittent springs and along the courses of ravines; sedges (Carex,