Western Pond Turtle


ORDER: Testudinidae

FAMILY: Emydidae

GENUS: Actinemys

SPECIES: marmorata

DESCRIPTION:
Western pond turtle's carapaces are olive, dark brown or blackish in color, the plastrons are yellow blotched with black. The shell color and markings can vary greatly, markings prevalent in young typically obscure as they age. There are occurrences of old individuals with irregular whitish patches on shells, necks, and heads. Adults measure 4 to 7 inches in length, with smooth edges on the shell.

GEOGRAPHICAL RANGE AND HABITAT:
The northwestern subspecies ranges from southern British Columbia south to central California, while the southwestern subspecies tends to be coastal, and ranges northward from northern Mexico to the San Francisco Peninsula. The two subspecies intergrade in the Central Valley, from north of Sacramento to Kern County going south. Western pond turtles prefer clam waters, like ponds, streams or pools, especially with vegetated banks.

DIET:
Western pond turtles are omnivorous feeders. Their main diet consists of crustaceans, midges, dragonflies, beetles, stoneflies, and caddisflies. Pond turtles are opportunistic and occasionally scavenge on mammal, bird, reptile, amphibian and fish carrion. Some sources say that males tend to eat more insects and vertebrates and females eat more algae and other plant material.

LIFE CYCLE/SOCIAL STRUCTURE:
The life span can be 40 to 80 years in the wild. Sexual maturity is reached at about 8-14 years. Mating takes place from May through August. Most females will lay eggs in alternating years, and both subspecies can lay twice a year during May through July. After a three month gestation hatchlings will often over winter in the nest, and emerge in the spring.

SPECIAL ADAPTATIONS:
This species exhibits sexual dimorphism, females are larger, and the shell is more raised than the male. Also males tend to have yellow throats and thicker tails bases.

INTERPRETIVE INFORMATION:
This aquatic turtle will spend a significant amount of time on land for overwintering purposes, and can move up to 4 times during the winter.

OUR ANIMALS:
Off exhibit in the BioDiversity Center

STATUS IN WILD:
Species is listed as vulnerable; adults face predation by a number of carnivores including racoons, otters, ospreys and coyotes. Hatchling turtles, being small with soft shells, are easily preyed upon by raptors, ravens, weasels, bullfrogs and large fish. Learn more in the conservation section of our website.

BIBLIOGRAPHY:

  1. Buskirk, J. (2002) The western pond turtle, Emys marmorata. Radiata: Journal of DGHT-AG Schildkroten, English Edition, 11: 3-30.
  2. Stanford University
  3. www.iucnredlist.org

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