Habitat Use by Wood Turtles in Central Pennsylvania

Abstract

-The behavior of a population of wood turtles was observed visually and by radio-tracking from 1984-1989. Their activity was centered around a creek that flowed through a mosaic of hemlock forest, hemlock swamp, deciduous forest, alder thickets, open grassy areas, and a cornfield. From November through March, the turtles hibernated in the creek. In April and October, when air temperatures were usually below 10 C at night and 20 C during the day, they usually remained in the creek. During other months they spent more time on land, mostly in the alder thickets, open areas, and cornfield. Males spent significantly more time in the creek and less time in open areas than did females. Within each sex there was considerable variation in the use of the different plant associations. The turtles spent each night in the creek or in shallow forms on land. Turtles on land, especially males, often returned to the creek at night, probably because of dehydration, cool temperatures, or social attraction. Some agricultural operations may locally benefit wood turtles by providing a mixture of different food and cover types near wooded creeks. tic data in population genetics and WRIGHT, S. 1965. The interpreta ion of po ulation i . . ered. 72:281-283. structure by F-statistics with special regard to sy , . L., ND J. D. NISWANDER. 1970. Poptems of mating. Evolution 19:395-420. Wood turtles, Clemmys insculpta, are found from Virginia north to Nova Scotia and west to Minnesota (Ernst and Barbour, 1972). Except for the box turtles (Terrapene spp.), they are the most terrestrial of the North American emydids. In some areas they range several hundred meters from the woodland creeks to which they retreat during cold weather (Carroll and Ehrenfeld, 1978; Barzilay, 1980; Quinn and Tate, 1991). This mobility is matched by a high degree of omnivory, suggesting a flexible and opportunistic use of the available habitats. Wood turtles eat fish, tadpoles, aquatic and terrestrial insects, spiders, earthworms, snails, slugs, bird and mammal carrion, algae, leaves, berries, and mushrooms (Surface, 1908; Babcock, 1919; Lagler, 1943; Barzilay, 1980; Strang, 1983). While it is generally known that wood turtles inhabit a variety of lotic and terrestrial habitats, there is a lack of published quantitative data on which to make detailed seasonal and geographical comparisons. As their populations decline and disappear, due largely to habitat loss, it is important to define habitat use by wood turtles so that effective recommendations can be made for their preservation. Much of the wood turtles' remaining habitat has been altered by agod turtles, Clem ys insculpta, are found Virginia north to Nova Scotia and west to i esota (Ernst and Barbour, 1972). Except for box turtles (Terrapen spp.), they are th most estrial of the North American emydids. In e areas they range sev ral hundre meters the wo dland creeks to whic t ey retrea ing cold weather (Carroll and Ehrenf ld, 8; Barzilay, 1980; Quinn and Tate, 199 ). This ility is matched by a high degr e of omory, sug esting a flexible and opp rtunistic ricultural practices. They now often roam through a mosaic of forest, streamside thickets, old ields, pastures, and cropland. As Harding and Bloomer (1979) noted, habitat preferences n this species can vary greatly, both seasonally and geographically. Further studies are needed in other parts of the species' extensive range. While studying the social behavior of wood turtle (Kaufmann, 1992), I collected data on habitat use that suggest the benefits and costs of a mixture of natural and agricultural envi-