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Canadian Herpetological Society Société d'Herpétologie du Canada |
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Western Painted Turtle
Chrysemys picta bellii
Family: Emydidae
The Western Painted Turtle is a sub-species of the Painted Turtle (Chrysemys picta).
COSEWIC status:- Special Concern (Intermountain - Rocky Mountain population)
- Threatened (Pacific Coast population)
- Not at Risk (Prairie / Western Boreal - Canadian Shield population)
- Special Concern (Intermountain - Rocky Mountain population)
- Threatened (Pacific Coast population)
- No Status (Prairie / Western Boreal - Canadian Shield population)
- Least Concern
Description
Western Painted Turtles have a smooth, gently rounded carapace (upper shell) that is dark green to black in colour with red markings on the sides. The plastron (lower shell) is usually bright orange or red with a large, irregular-shaped dark blotch in the centre. The head and the limbs are black to dark green with yellow stripes. Individuals can reach a maximum carapace length of 25.5 cm, but most are smaller than this. Hatchlings have an average carapace length of 2.5 cm and resemble adults in colour and pattern, but with a keeled carapace and proportionately larger head, legs and tail.
Similar Species
Western Painted Turtles can easily be distinguished from the similar Midland Painted Turtle and Eastern Painted Turtle based on distribution, although there is a zone of overlap with the Midland Painted Turtle in northwestern Ontario. Western Painted Turtles have more of an orange or red colouration to the plastron with a large, irregular-shaped dark blotch in the centre and they lack red stripes on the neck. They can be distinguished from the Western Pond Turtle (extirpated in Canada) by the bright yellow stripes on the neck and legs. The exotic Red-eared Slider usually has a pronounced red marking behind the eye and the rear margin of the shell is lightly serrated.
Distribution
Click for larger image
Painted Turtles have the widest range of any freshwater turtle in Canada, occurring from British Columbia to Nova Scotia. The Western Painted Turtle occurs throughout the southern portion of western and central Canada from British Columbia to northwestern Ontario. In the United States, the Western Painted Turtle subspecies also occurs from Wisconsin south to Missouri and northern Oklahoma west to Washington and northern Oregon, as well as in isolated populations in several southwestern states.
Habitat
Painted Turtles inhabit shallow aquatic habitats with slow-moving water, soft bottoms, aquatic vegetation, and abundant basking sites. They occur in a diversity of habitat types, including swamps, marshes, permanent or temporary ponds, creeks, rivers and lakes. In the prairies, the Western Painted Turtle tends to be associated with rivers and is uncommon in wetlands and prairie potholes. Females nest in sandy or gravelly soils in open-canopy habitats with high sun exposure, such as in forest clearings, meadows, shorelines, fields, and the shoulders of roads. The nest sites are typically within 200 m of a water body. Painted Turtles overwinter at the bottom of water bodies or under submerged undercut banks.
Biology
In Canada, Western Painted Turtles are dormant during the winter and are typically from April until late September or October. Painted Turtles nest from late May to early July. The female excavates a nest cavity and lays 4–23 (average 12) elliptical eggs. The number of eggs laid varies with age and size of the individual and the number of clutches produced (females usually reproduce every year, but may lay more than one clutch). The eggs hatch in the fall, approximately 2.5 months after they were laid, but some individuals overwinter in the nest before emerging the following the spring. Painted Turtle hatchlings are capable of supercooling and are freeze-tolerant, allowing them to survive sub-zero temperatures as low as −10°C in the nests. The sex of the offspring depends on incubation temperature; warmer incubation temperatures produce females and cooler temperatures produce males. In Canada, female Painted Turtles reach sexual maturity at 12–15 years of age, and males mature between 7–10 years of age. Painted Turtles can live for over 50 years in the wild, and possibly much longer. Painted Turtles are omnivorous and forage primarily during the day for invertebrates, small vertebrates like fish or frogs, carrion, and a variety of plant material. Painted Turtles bask regularly throughout the active season, especially on sunny days. Individuals may make use of multiple wetlands over the course of the year, and home ranges can be several kilometres in length.
Threats
Extensive wetland loss in coastal B.C. has caused significant declines of the Pacific Coast Population, and ongoing habitat loss continues to threaten this species throughout its Canadian range. Painted Turtles are especially susceptible to mortality on roads, particularly during the nesting period when females are making overland movements. Since Painted Turtles are relatively long-lived, even low rates of road mortality can result in population decline. Nest predation by subsidized predators (e.g. Raccoon, Skunk) can be a serious threat in areas where these nest predators are hyper-abundant. Other threats include illegal collection for food or as pets, introduction of exotic or invasive species, mortality and injury from fishing by-catch (including drowning in commercial fishing traps), and chemical contamination of aquatic habitats. Climate change poses a potentially serious future threat to Canadian turtles.