New York Status: Endangered
Federal Status: Threatened
The bog turtle is New York's smallest turtle, reaching a maximum length of 4.5 inches. A bright yellow or orange blotch on each side of its head and neck are a distinctive feature of this species. The body color is dark with an orange-red wash on the inside of the legs of some individuals. The carapace (upper shell) is domed and somewhat rectangular, often with prominent rings on the shell plates (scutes). Older individuals may have smooth or polished shells, likely a result of burrowing into coarse soils. Generally dark brown, the carapace is sometimes highlighted by a chestnut sunburst pattern in each scute. The plastron (lower shell) is not hinged and patterned with black blotches. As with most turtles, the plastron of the male is slightly concave while in females it is flat.
Bog turtles emerge from overwintering sites by mid-April. Overwintering sites are typically found in densely vegetated areas often in association with tree roots and other submerged structures along streams or near underground springs. Abandoned muskrat lodges and a variety of wetland burrows may also be used. These overwintering sites can become communal in nature, housing many bog turtles and spotted turtles (Clemmys guttata). Turtles emerge when the air and water temperature exceed 50 degrees (F). This is necessary for the turtles to become active.
Mating generally occurs in the spring but autumn mating events are documented. This may be focused in or near their winter shelters. Nesting sites are typically located inside the upper part of an unshaded tussock (a tall, thick bunch of grass). A clutch of two to four eggs are deposited in early to mid-June, hatching around mid-September. It's been occasionally documented that some hatchings in southern populations overwinter in the nest, emerging the following spring. Bog turtles return to their overwintering sites in later October. Sexual maturity may be reached as early as eight years of age or as late as eleven. They may even live for more than 30 years.
This species is secretive in nature. The bog turtle can be seen basking in the open when the conditions are favorable for such behaviors, especially in the early spring. It is an opportunistic feeder, eating what it can get. It prefers invertebrates such as slugs, worms, and insects though seeds, plant leaves, and carrion are also included in its diet.
Distribution and Habitat
The bog turtle is found in scattered, separate colonies in the eastern United States from New York and eastern Massachusetts, south to eastern Tennessee and northwestern Georgia. This is a semi-aquatic species, preferring habitat with cool, shallow, slow-moving water with deep muck soils, and tussock-forming vegetation.
In New York, the bog turtle is generally found in open, early-successional types of habitats such as wet meadows or open calcareous boggy areas generally dominated by sedges (Carex spp.) or sphagnum moss. Like other cold-blooded or ectothermic species, it requires habitats with a good deal of sunlight for basking and nesting. Plants such as purple loosestrife (Lythrum salicaria) and reed (Phragmites australis) can quickly invade such areas resulting in the loss of basking and nesting habitat.
Of the more than 180 known bog turtle sites that occur in New York, a little more than half (61%) are known to support surviving populations. Due to the decreasing numbers found in these sites and difficulty in finding bog turtles, some sites are thought to no longer contain bog turtles; however, they may still contain a few individuals.
More than half of the 74 historic bog turtle locations in New York still contain what appears to be suitable habitat. About half of all bog turtle populations in the state have shown evidence of reproduction, such as finding juveniles, verified nests, or egg shells from hatched nests. Most of these populations have shown declines over time. Less than 15% of bog turtle populations in the state are ranked as having good to excellent survival rates. This means that long term persistence of many populations is thought to be rather low.
Pesticide contamination from agricultural run-off and industrial discharge may negatively affect the bog turtle and its habitat. Contaminants may also accumulate in invertebrates that turtles eat.
The primary threats to this species are loss/degradation of habitat and illegal collecting. In New York, development and natural succession (vegetation growing in over time) are the major threats to bog turtle populations. As sites deteriorate-are taken over by shady plants or invasive species-bog turtles normally move out of their old sites to new areas where fire, beavers, agriculture, or other events have created an open wet meadow-type habitat. However, residential and commercial development-especially roadway and reservoir construction-prevents their ability to move to new, potential habitat. So, new populations cannot be created as old sites deteriorate.
Collection of the bog turtle without a permit is prohibited in all states where it occurs. It was listed as threatened in 1997 by the U. S. Fish and Wildlife Service (USFWS), and has been listed in CITES Appendix I, (Convention of International Trade in Endangered Species) since 1975. Unfortunately, illegal collection still continues to threatening this long-lived, slow reproducing turtle.
Management and Research Needs
DEC has been conducting field surveys of historic, known surviving, and potential bog turtle sites in accordance with USFWS recommendations. Staff use these surveys to determine trends in population size, habitat suitability, and knowledge of their distribution. Some currently inhabited bog turtle sites and some historic sites are under the ownership of DEC or other conservation organizations.
Many of the best remaining sites remain in private ownership and efforts have been made to restore and maintain habitat through programs such as the former Landowner Incentive Program. The success of this program was twofold. The restoration work expanded available habitat for a healthy population of bog turtles. Additionally, it served as a means for other interested landowners to develop relationships and enter agreements with federal agencies, such as the Natural Resources Conservation Service, to restore habitat and prevent further declines.
Researchers are also studying reproductive potential, daily and seasonal movements, and habitat use, as well as identifying hibernation areas by tracking animals fitted with radio transmitters. Since the bog turtle is sensitive to habitat changes that are the result of natural succession, they are also studying how bog turtle populations respond to these changes.