Hibernation of the Box Turtle

Abstract

THE early issues of COPEIA contain a number of notes on the habits of box turtles in relation to hibernation and aestivation. Thus Nichols (3, 1914) remarks about a box turtle active in December in New Jersey; Culver (22, 1915) discusses one swimming a creek; Overton (26, 1916) calls attention to the fact that T. c. carolina takes to water in hot weather; Engelhardt (31, 1916) reports aestivation in a burrow of mud near water; Babcock (49, 1917 )shows that young box turtles take to water in captivity; and Wetmore (77, 1920) describes the hibernation in dirt. Some recent observations by the writer may be of interest in regard to the hibernation of Terrapene carolina carolina. When I left Urbana, Illinois, in June, 1931, I turned 17 specimens of Terrapene ornata and 24 specimens of T. carolina carolina, all native Illinois specimens, loose in an outdoor pen. This pen has a natural dirt surface, with numerous shrubs, herbs and grasses growing in it. At one end a water pipe runs a constant stream to form a little puddle about a yard square and some 6 inches deep. The females were with eggs, as dissection of some specimens of both species showed, and it was hoped that they would eventually present me with young turtles for study. A count of noses on my return in September showed all turtles present and accounted for, but there were no young. However, on October 2, I suddenly found 5 young of T. carolina carolina crawling about and headed for the pond at the opposite end of the pen; one was already in the water. All 6 babies eventually congregated in the water, where I collected them. This brood of 6 accounts for the activities of one adult female, and that is all the young I have found. Incidentally it may be noted that this aquatic tendency of young box turtles may well explain why small specimens of the species are so seldom found in the field; half buried in the muck and leaves at the bottom of a pond they are very hard to locate. With the approach of cooler weather in late October, every specimen of T. ornata dug in and disappeared while all of the T. carolina carolina remained out and active. On November 2 these began to dig in, and 7 of 24 went into hibernation. A week later 5 more began to dig in, but these, as well as the preceding 7, came out again during the day, repeating the performance of digging in in the late afternoon and coming out again in the morning, for five days and nights. Then for three more days 7 other specimens joined in the temporary nocturnal hibernation. At the end of this time all 19 went in for good. While this large group was deciding whether or not to hibernate, it was noted that the remaining 5 turtles had entered the pond and were lying entirely quiescent in the water, head and legs drawn in. They were in such a position in relation to the bank that they could get their nostrils out of water without moving the body. And there they remained all winter, moving hardly at all during the period from December to March, with few exceptions. On January 28 one was out on the shore, but it returned to the water early in the afternoon and did not