Description: Western pond turtles are generally yellowish with dark blotches in the center of the plastron. There is marbled patterning throughout the body. The dorsal area is generally dark brown to olive. The shell tends to be low, wide, and smooth. Adult males have a larger head, pointier snout, thicker tail base, and a wider neck characterized by white and yellow on the chin and throat. Adult females tend to have a blunt snout, thinner tail base, and darker markings on the chin and throat. Western pond turtles have webbed feet. Hatchlings tend to have a longer tail, soft shell, and be a lighter brown; darkening as they age. They weigh approximately 0.15 ounces at hatching and measure around 1.1 inches in shell length. The southern subspecies tends to grown only to 4.5 inches in shell length, northern subspecies reach 8.25 inches in shell length.

The dorsal color of A. marmorata is usually dark brown or dull olive, with or without darker reticulations or streaking. The plastron is yellowish, sometimes with dark blotches in the centers of the scutes. The straight carapace length is 4.5 to 8.5 inches. The carapace is low and broad, usually widest behind the middle, and in adults is smooth, lacking a keel or serrations. Adult western pond turtles are sexually dimorphic, with males having a light or pale yellow throat.

Habitat: Western pond turtles use both aquatic and terrestrial habitats. They are found in rivers, lakes, streams, ponds, wetlands, vernal pools, ephemeral creeks, reservoirs, agricultural ditches, estuaries, and brackish waters. Western pond turtles prefer areas that provide cover from predators, such as vegetation and algae, as well as basking sites for thermoregulation. Such cover also provides shelter when wintering. Western pond turtles are observed in aquatic habitats ranging from 33.8 to 104℉. Juveniles are found primarily in areas between 53.5 and 91.4℉, whereas adults are found between 10 and 62.6℉. Adults tend to favor deeper, slow moving water, whereas hatchlings search for slow and shallow water that is slightly warmer. Terrestrial habitats are used for wintering and consist usually of burrows in leaves and soil. Western pond turtles also lay their eggs in terrestrial habitats.They are rarely found at altitudes above 5000 feet.

Range: Range extends from Washington or British Columbia to central California; distribution and abundance have declined as a result commercial exploitation for the pet trade, habitat loss and degradation, introduced species, and (locally) disease.

Found in these States: CA | OR | WA

Diet: The western pond turtle is omnivorous and most of its animal diet includes insects, crayfish, and other aquatic invertebrates. Fish, tadpoles, and frogs are eaten occasionally, and carrion is eaten when available. Plant foods include filamentous algae, lily pads, tule and cattail roots. Juveniles are primarily carnivorous, and eat insects and carrion. At about age three they begin to eat plant matter.

Reproduction: Sexually mature females of the western pond turtle produce 5 to 13 eggs per clutch. They deposit eggs either once or twice a year. They may travel some distance from water for egg laying, moving as much as 1/2 mile away from and up to 300 feet above the nearest source of water, but most nests are within 300 feet of water. The female usually leaves the water in the evening and may wander far before selecting a nest site, often in an open area of sand or hardpan that is facing southwards. The nest is flask shaped with an opening of about 2 inches. Females spend considerable time covering up the nest with soil and adjacent low vegetation, making it difficult for a person to find unless it has been disturbed by a predator.

The vast majority of western pond turtle hatchlings overwinter in the nest, and this phenomenon seems prevalent in most parts of the range, especially northern areas. This might explain the difficulty researchers have had in trying to locate hatchlings in the fall months. Winter rains may be necessary to loosen the hardpan soil where some nests are deposited. It may be that the nest is the safest place for hatchlings to shelter while they await the return of warm weather. Whether it is hatchlings or eggs that overwinter, young first appear in the spring following the year of egg deposition. Individuals grow slowly in the wild, and their age at their first reproduction may be 10 to 12 years in the northern part of the range. The western pond turtle may survive more than 50 years in the wild.

Status: urrent threats to western pond turtles are numerous and include fire, flooding, drought, upper respiratory disease, habitat destruction, and lack of genetic variation. The lack of variation is due to the isolation of individual populations over ranges to large to be covered by migration. Habitat destruction is the result of intense urbanization. Additionally humans pose a great threat via off-road vehicles, chemical spills, and incidental catch by fishermen. Lack of research has prevented western pond turtles from being added to the federal endangered species list.

Subspecies: Two found in the United States:
   Northern Pacific Pond Turtle (Actinemys marmorata marmorata)
   Southern Pacific Pond Turtle (Actinemys marmorata pallida)

Taxonomy: