New York Status: Endangered
Federal Status: Not Listed
Description
The mud turtle is a small, nondescript reptile, measuring 3-4 inches (7.5-10 cm). The carapace (upper shell) is olive to dark brown to almost black, patternless, smooth and keelless. It has only 11 marginal scutes (plates) rather than the 12 found on most turtles. The plastron (lower shell) is yellow to brown, double-hinged, with 11 plates. Males have a well-developed, blunt spine at the tip of the tail and rough scaly patches on the inside of the hind legs.
Life History
Most of the life history information is based on studies conducted at the southern end of the range. Breeding occurs soon after the turtles leave hibernation, which in New York occurs from late April to May. In June, the female digs a 3-5 inch cavity in vegetative debris or in sandy loam soil, where she deposits 2-6 eggs. In the south, three clutches are typically laid each year, but in New York, one clutch is most likely. The eggs incubate for an average of 76 days, but may overwinter in the nest. Muskrat and beaver lodges are occasionally used as nest sites. Females reportedly reach sexual maturity in 5-8 years; males require only 4-7 years. In New York, though, sexual maturity may take 8-11 years.
Distribution and Habitat
The range of this species covers Long Island, south to southern Florida, west to central Texas, and north up the Mississippi Valley to southern Illinois and southwestern Indiana. An isolated population occurs in northwestern Indiana. In New York, there are only five populations remaining. Within their range, mud turtles are semi-aquatic, though they often wander away from water in mid-summer. They can be found in fresh or brackish water, including marshes, small ponds, wet ditches and fields, and offshore islands. They prefer shallow, soft-bottomed, slow-moving water with abundant vegetation. Individuals can be seen prowling pond bottoms during warmer months. If the habitat dries up, they may move over land to another body of water, or burrow into the mud and aestivate (pass the summer in a state of stupor). In New York, mud turtles hibernate from September to April or May. Of all turtle species in New York, the mud turtle apparently has the shortest activity period. Burrows, 1 to 3 feet deep in mud, sand or dry leaves at marsh or field edges, below the frost line, are used for overwintering. Mud turtles migrate 200-400 meters from their pond to nest.
Status
The mud turtle is the rarest species of turtle in New York. Mud turtles are seen crossing roads, most likely in search of nest sites or water. Turtles killed by passing cars are a very significant loss to populations. Draining wetlands for urban and industrial development has impacted populations, reducing the amount of suitable habitat. Upland nesting and hibernation sites have also been impacted by land clearing, development and fragmentation from road construction. Overcollecting for the illegal pet trade exploits adults necessary for sustaining populations.
Management and Research Needs
Additional effort is needed to survey for mud turtles in potential habitat. Studies to identify upland habitat requirements have begun and need to be continued. At this time, efforts aimed at protecting mud turtles should concentrate on the acquisition and management of habitat where populations are still known to occur. Educating the public regarding the illegal pet trade and enhancing their awareness of statutory protection should be encouraged. Recommended habitat management activities include 1) elimination of barriers that hinder migration between ponds and nest or hibernation sites, 2) placement of "turtle crossing" signs to warn motorists of the turtle's presence in key areas, and 3) maintenance of open areas for nesting.
Additional References
Behler, J. L. and R. W. King. 1979. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, New York.
Conant, R. and J. T. Collins. 1998. A Field Guide to Reptiles and Amphibians of Eastern and Central North America. Third Edition Expanded. Houghton Mifflin Co., Boston.
Ernst, C. H., J. E. Lovich and R. W. Barbour. 1994. Turtles of the United States and Canada Smithsonian Institution Press, Washington and London.
Pritchard, P. C. H. 1979. Encyclopedia of Turtles. T. F. H. Publications, Neptune, New Jersey.
Map adapted from Conant and Collins (1998) and Ernst, Lovich and Barbour (1994)
