Plymouth Red-bellied Turtle

Pseudemys rubriventris bangsii

Description

At maturity, the Plymouth red-bellied turtle, Pseudemys rubriventris bangsii, achieves a carapace (upper shell) length of up to 12 in (31 cm). The carapace is typically black to deep mahogany with reddish vertical bars, but color and patterning vary widely. The male undershell (plastron) is pale pink, overlaid with a dark mottling. The female under-shell is a brilliant coral red. The upper jaw is notched and displays distinct cusps.

Behavior

This turtle is primarily aquatic, preferring small ponds but is occasionally found on land near the water. It is most active from late March to October. In the winter it rests on the pond bottom beneath the ice in an inactive state similar to hibernation, known as brumation. It feeds on aquatic vegetation, crayfish, and other small pond fauna. In late spring and early summer, the female selects a nesting site in sandy soil close to the pond. After scooping a hole, she deposits 10-17 eggs, which incubate between 73 and 80 days. Hatchlings are only about 1 in (2.5 cm) long. Hatchlings may emerge from nests to enter ponds in late summer, or overwinter in the nest chamber and emerge the following spring. Females reach sexual maturity in 8-15 years; males may mature earlier.

Habitat

The Plymouth red-bellied turtle prefers deep, permanent ponds with nearby sandy areas for nesting, and surrounding vegetation of pine barrens or mixed deciduous forest.

Distribution

Archaeological evidence suggests that this species occurred in a fairly restricted area of eastern Massachusetts defined by Ipswich, Concord, and Martha's Vineyard. A closely related subspecies, the red-bellied turtle (Pseudemys rubriventris rubriventris ), ranges from North Carolina to southern New Jersey.

The Plymouth red-bellied turtle is thought to be limited to about 17 ponds and one river site in Plymouth County, Massachusetts. The total number of breeding individuals is believed to be about 300.

Threats

The greatest threat to this turtle is its limited distribution. Many of the habitat ponds are within an area of only 1,500 acres (607 hectares). In the early 1980s, Plymouth County experienced a development boom. Pondshore land, in particular, was considered prime for residential development. The Massachusetts Wetlands Protection Act provided some protection against alteration of turtle pond habitats. But even when ponds were left intact by construction, houses and roads eliminated nesting and basking sites.

Other negative impacts on this turtle include incidental mortality from highway traffic, occasional shooting, and use as pets. Another threat could arise in the future if pond levels were subject to extensive draw downs as might occur if the Plymouth aquifer were tapped as a water source for metropolitan areas. Such draw downs could affect the turtle's food supply as well as cover.

Predation by raccoons, skunks, and widemouth bass is also considered a serious threat to the turtle population. Raccoons and skunks dig out nests and eat the eggs, while bass snatch turtle hatchlings from the water before the shells have a chance to harden. To counter this threat, researchers under the direction of the Massachusetts Natural Heritage and Endangered Species Program began locating turtle nests and fencing sites to exclude predators. At the time of fencing, several eggs are removed from each nest, then hatched and raised in a collaborative captive breeding program.

Hatchlings are held over the winter, during which time they develop at a rate five times faster than those remaining in the wild. By spring, these young turtles are able to resist predation and are released into the turtle ponds.

Conservation and Recovery

To counter habitat loss, The Nature Conservancy included several turtle ponds in its land registry program in Massachusetts. Under this system, landowners voluntarily agreed to avoid activities on their lands that would harm the turtle. This voluntary program provided the nucleus for the establishment of a permanent federal wildlife refuge in 1986. The refuge includes all turtle ponds known to be inhabited and others that were once inhabited.

While an active head start program has introduced turtles to several new ponds and the river site, and has significantly increased the number of turtles in other ponds, the turtles take years to reach breeding status. It is therefore premature to evaluate the ultimate success of this effort.

The primary management objective for this turtle is to restore and maintain self-sustaining populations. Reclassification to threatened status could occur if the species increases to at least 15 self-sustaining populations with 600 breeding-age individuals. Delisting will be considered when numbers increase to 1,000 breeding-age turtles in 20 or more self-sustaining populations (in ponds, lakes and possibly rivers). In addition to the population targets, maintenance of sufficient habitat to allow long-term survival of the population and an understanding of the turtle's life history and habitat requirements sufficient for management purposes, will be required to meet the full recovery objective.

The potential for recovery is reasonable if nest predation can be prevented and if head starting of young is done on a larger scale than in the past. Due to the limited range of this species, delisting may not be possible. Reclassification may be possible by the year 2000, if ongoing recovery efforts continue to be successful.

Contact

U.S. Fish and Wildlife Service
Division of Endangered Species
300 Westgate Center Drive
Hadley, Massachusetts 01035
http://northeast.fws.gov/

References

Graham, T. E. 1984. "Pseudemys rubriventris Predation." Herpetology Review 15: 19-20.

U. S. Fish and Wildlife Service. 1985. "Plymouth Red-Bellied Turtle Recovery Plan." U.S. Fish and Wildlife Service, Newton Corner, Massachusetts.

U. S. Fish and Wildlife Service. 1994. "Plymouth Red-Bellied Turtle Recovery Plan, Second Revision." U.S. Fish and Wildlife Service, Newton Corner, Massachusetts.