University of Massachusetts Amherst

Massachusetts North American Amphibian Program

Northern Red-bellied Cooter

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Herp Atlas 1992-1998 Survey

  • The map below shows the distribution of the Northern Red-bellied Cooter in Massachusetts based on the original intensive volunteer survey that took place from 1992-1998.
  • Download pdf of map

Updated Distribution Map

Pseudemys rubriventris (10-12”)
Federal Status: “Threatened”; MA Status: "Endangered." Illegal to harass, kill, collect or possess.

The Red-bellied Cooter is a large 10 -12 inch basking turtle that can weigh up to 10 pounds. The carapace (upper shell) of an adult Red-bellied Cooter is black to mahogany colored with light chestnut or red markings. The tip of the upper jaw is notched, and a yellow arrow-shaped stripe runs along the neck to atop the head. The plastron (bottom shell) of the males is pale pink overlaid with dark mottling, while females have red plastrons with borders of grey along the seams of the shell plates. The color of the head, neck, limbs, and tail is black, with yellow or ivory lines. Both sexes usually become progressively melanistic (blacken) with age. Males are smaller, have longer tails and longer front claws than females.

Hatchlings are about 1 inch long and are more circular in shape than adults. They have a slightly keeled olive green carapace marked with greenish-yellow hieroglyphics. Like adults, juveniles have yellow stripes on the head, neck, and limbs.

The Northern Red-bellied Cooter in is an isolated disjunct population in Massachusetts and is currently confined to ponds within Plymouth County. This population of turtles was formerly described as a distinct subspecies, P. rubriventris bangsi (Plymouth Redbelly Turtle). The primary range of the Red-bellied Cooter is from the coastal plain of New Jersey south to North Carolina and inland to West Virginia. Archaeological evidence from Indian encampments suggests that before European settlement, this turtle occurred in one continuous population throughout coastal Massachusetts and south to North Carolina.

In Massachusetts, the Red-bellied Cooter primarily inhabits freshwater ponds of varying sizes that have abundant aquatic vegetation, although there have been a few observations along riverways. For nesting, the Red-bellied Cooter requires sandy soil on land surrounding the pond.

Red-bellied Cooters overwinter at the bottom of ponds and most likely in streams. During the active season they are almost exclusively in water. Females will come out to nest and occasionally individuals will migrate from one water body to another. Red-bellied Cooters bask on logs and woody debris throughout the active season. The Red-bellied Cooter feeds primarily on aquatic vegetation, particularly milfoil (Myriophyllum spp.). Especially when young, it may occasionally eat crayfish and invertebrates.

Mating occurs in shallow water in the spring. In late June or early July, the female begins nesting activity. Females typically nest within 100 yards from the water’s edge. In Massachusetts, females typically lay 10-20 eggs and incubation lasts approximately 73 to 80 days. Red-bellied Cooters exhibit temperature dependant sex determination; warmer nest site temperatures produce females and cooler sites produce males. Hatchlings emerge from late August through October. Some hatchlings may overwinter in the nest if the late summer weather is unseasonably cool. Once out of the nest chamber, hatchlings head for the pond.

Adapted from the MA Natural Heritage and Endangered Species Program’s Northern Red-bellied Cooter fact sheet. 2008



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