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Blanding's Turtle (Emydoidea blandingii) Habitat: Blanding's turtles are primarily aquatic, and in Maine they frequent vernal pools, marshes, shrub swamps, slow-moving rivers and streams, and even farm ponds. Shallow, dark, heavily-vegetated waters are preferred (Power et al. 1994). In riverine locations, they select the slow-moving waters characteristic of oxbow marshes. Vernal pools are extremely important feeding areas in the spring and summer. Radio-tagged turtles in Maine used as many as 6 different wetlands during the summer, sometimes traveling up to 2 km (1.2 mi) between wetlands (Joyal 1996).Terrestrial activity was common in Maine and included travel between foraging wetlands, and nesting, estivation and hibernation sites. Nest sites include loam, sand, and even gravelly substrates. Plowed farmlands are favored nesting places in Massachusetts (Graham unpubl. data). In Maine, nest sites include pastures, road edges, yards, and soil-filled cracks in bedrock (Joyal 1996). Although habitat requirements of the young are unclear, it has been reported that they spend a portion of their time in emergent sedge and alder hummocks around the periphery of marshes (Pappas and Brecke 1992). Newly emerged hatchlings may enter wetlands different from those used by adults or instead burrow in dry vernal pools before eventually entering permanent wetlands (Butler and Graham 1995). About half of Maine Blanding's turtles estivate, or remain inactive, from mid-July to September under leaf litter in forested uplands. Turtles move to hibernation sites (vernal pools; shallow, grassy swales; shrub swamps; and ponds) in September. Reproduction: Blanding's turtles probably reach maturity at 12-15 years of age (Graham and Doyle 1977; Congdon et al. 1983). Courtship and mating have been observed in Maine from May to July (Joyal 1996), and Ernst and Barbour (1972) noted that copulation has been seen in every month from March to November (most often from March to May).The female lays a clutch of 5-13 eggs in Maine (Graham and Forsberg 1986; Joyal 1996). Nesting takes place on land during about 2 weeks in mid-June. Hatchling emergence from nests in York County, Maine occurred 68-118 days (August 25-October 10) following egg deposition (Joyal 1996), but may take as much as 126 days (Moriarty and Linck 1995). Apparently not all females produce eggs every year (Congdon et al. 1983). Diet: Blanding's turtles are reported to feed on land as well as in the water. Their aquatic menu includes larval amphibians, crustaceans, insects, molluscs, plants, and fish, while their terrestrial diet contains vegetation, berries, slugs, insect larvae, and earthworms. In Maine, Blanding's turtles have been observed feeding on wood frogs and tadpoles (Joyal 1996) and the scat from one Maine female contained many tiny aquatic snail shells (Graham unpubl. data). In Illinois, Rowe (1992) found that animal foods constitute >86% of this turtle's dietary volume. Interactions with People and Other Animals: Being extremely docile by nature, Blanding's turtles will seldom bite even if poked on the snout. They are very timid and sometimes attempt to flee when approached in the water. They are powerful and swift swimmers, but occasionally, in dark, heavily-vegetated water, or water covered with a carpet of duckweed, they will pull in and sit quietly on the bottom until all sign of danger has passed (Sexton 1995). Although their nests are frequently destroyed by mammalian predators, and some adults are killed annually crossing roadways, a far greater threat to the future of the Blanding's turtle lies in the alarming loss and fragmentation of available nesting and wetland habitat. Marshland manipulation (including both drainage and impoundment) has certainly reduced available habitat. Residential development and associated loss and isolation of small wetlands (especially vernal pools), increased road mortality, and alteration of upland travel corridors are the most serious factors threatening Blanding's turtles in Maine (McCollough 1991). Conserving all wetlands, upland corridors between wetlands, and nesting habitat, together with strict water pollution control, will be vital to the survival and recovery of the Blanding's turtle in Maine. Habitat conservation efforts are being initiated at several large patches of relatively undeveloped habitat, especially in the Mount Agamenticus area in southern Maine. (Terry
E. Graham,Worcester State College, |
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