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Canadian Herpetological Society Société d'Herpétologie du Canada |
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Spotted Turtle
Clemmys guttata
Family: Emydidae
COSEWIC status:- Endangered
- Endangered
- Endangered
Description
The Spotted Turtle has a smooth, black carapace (upper shell) with distinct yellow spots on it. The head, limbs and tail are black with vibrant yellow and orange markings. The plastron (lower shell) is orange with large black markings on each scute (enlarged scales on the shell). Females have orange eyes and light chins, whereas males have brown eyes and dark chins. This is one of Canada’s smallest turtles, with maximum carapace length of about 14 cm. Hatchlings have a carapace length of 2.6–3.1 cm and resemble the adults, but they may lack pronounced yellow spots on the carapace.
Similar Species
Spotted Turtles are easily distinguished from all other Canadian Turtles by the distinct yellow spots on their otherwise black carapace. Blanding’s Turtles can have pronounced yellow flecking on their carapace, but they lack large yellow spots. Blanding’s Turtle adults also have a higher, domed carapace, but the carapace of juveniles is less domed.
Distribution
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In Canada, the Spotted Turtle is limited to southern Ontario. There are historic populations in southwestern Quebec, but no recent records. In the United States, this species occurs around the Great Lakes from northeastern Illinois east to New York state, and along the Atlantic seaboard from southern Maine south to southern Florida.
Habitat
Spotted Turtles live in shallow water bodies with soft bottoms and emergent vegetation, such as bogs, coastal wetlands, fens, marshes, ponds and swamps. Individuals overwinter, often communally, underwater in shallow wetlands such as swamps and fens. Females dig nests in sand, soil or moss in open-canopy areas with high sun exposure, such as in forest clearings, meadows, shorelines, and rock outcrops. Females may move short distances overland to lay their eggs, but the nests are typically quite close to their aquatic habitats.
Biology
In Canada, Spotted Turtles are dormant during the winter and are typically active from April until early October. Breeding is most common early in the spring while individuals remain congregated at overwintering sites, but it may occur any time during the active season. Females lay 3–7 eggs in June, and the eggs hatch in September or early October. The sex of Spotted Turtles is determined by incubation temperature of the eggs; cooler temperatures produce males and warmer temperatures produce females. In Canada, female Spotted Turtles mature at 12–15 years of age and males mature slightly younger, at 11–13 years of age. Females at northern latitudes may reproduce every year, but often skip years. Spotted Turtles have exceptionally high adult survivorship and are likely capable of living over 100 years. This species is active early in the spring, but may become relatively inactive during the warmer summer months. Spotted Turtles forage in aquatic habitats for a variety of invertebrates such as insects and small crustaceans, as well as fish, tadpoles, carrion and vegetation.
Threats
The extensive drainage and conversion of wetlands into agricultural and urban areas has resulted in the decline and extirpation of Spotted Turtles throughout much of their range in southwestern Ontario, and ongoing habitat loss continues to threaten this species throughout its Canadian range. The rapid spread of the highly invasive European Common Reed (Phragmites australis australis) is also causing the widespread conversion of this species’ habitat into unsuitable areas. Since Spotted Turtles are very long-lived and reproductive potential is low, even low rates of mortality on roads 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. Incidental removal from the wild and collection for the illegal pet trade is also a significant threat to Spotted Turtle populations. Climate change poses a potentially serious future threat to Canadian Turtles. Most remaining populations are now small and isolated from each other, increasing extinction potential by limiting genetic exchange.