The spotted turtle (Clemmys guttata) is a small freshwater turtle native to Eastern North America. It is named for the bright yellow or yellow-orange spots on its shell, head and limbs. Its Canadian range is restricted to Southern and Central Ontario, where it is found in shallow wetland habitats such as swamps, marshes, fens and bogs. The spotted turtle is endangered, both in Canada and globally.
Female spotted turtles can reach an upper shell (carapace) length of 14.25 cm, while males are slightly smaller, with a maximum upper shell length of 12.2 cm. The smooth, slightly domed upper shell is black with pronounced yellow or yellowish-orange spots. The bottom shell (plastron) is yellow, orange or cream-coloured with large dark blotches, but it can become completely black on older individuals. The head, neck, upper surface of the legs and tail are dark grey to black with scattered yellow or yellowish-orange spots, while the underside of the legs are yellow to pinkish-orange. Males have a tan chin and brown eyes, whereas females are more brightly coloured and have a yellow or orange chin and eyes.
Distribution and Habitat
In Canada, spotted turtles are found only in Southern and Central Ontario. Although there are a few old, unverified reports of the species in Southern Quebec, there are no confirmed sightings of the species in that province. In Ontario, spotted turtles have a patchy distribution in Southwestern and Southeastern Ontario that extends north into Muskoka and along the eastern shore of Georgian Bay. Many populations are small and isolated. In the United States, the spotted turtle’s range extends west from Maine to Northeastern Illinois and south along the Atlantic Coast to Central Florida.
Spotted turtles live in shallow-water habitats that typically have soft, mucky bottoms and vegetation (e.g., cattails, grass, sedge tussocks and shrubs). These habitats include marshes, swamps, fens, bogs, ponds, slow-flowing creeks and shallow bays of lakes. Individuals often move between multiple wetlands throughout the year. Females nest on land, typically within a few hundred metres of the nearest wetland. Nests are laid in sunny habitats where warm temperatures help the eggs develop. Spotted turtles will travel over land when migrating between wetlands or to nesting sites. During the summer, spotted turtles sometimes avoid hot temperatures by moving into terrestrial habitats and becoming dormant, a process called aestivation. Spotted turtles hibernate in the winter below the ice in shallow wetlands (e.g., typically less than 50 cm of water). Some individuals hibernate singly, but others congregate in large groups, with at least 16 individuals observed hibernating together in one Ontario population. Despite their small size, spotted turtles can have relatively large home ranges spanning over 1 km. Spotted turtles show high fidelity to their hibernation and breeding sites, meaning they typically return to the same sites year after year.
Did you know?
Some of Canada’s turtle species, including the spotted turtle, are threatened by poaching and illegal wildlife trafficking. Their ornate appearance and growing rarity, among other characteristics, have created a demand for these species in the illegal wildlife trade. Individuals are illegally collected from the wild and sold through the black market. International criminal organizations often coordinate these activities, and many of these turtles are smuggled across borders and shipped overseas. Since freshwater turtles have long lifespans and slow population growth, poaching can have a significant, often irreversible impact on local populations.
Reproduction and Development
Spotted turtles congregate at breeding sites and mate in the early spring. In Canada, females lay a clutch of 1–7 eggs from late May to late June. Female spotted turtles in Canadian populations typically reproduce every 1–2 years, but some females may go several years without reproducing. Hatchlings emerge from the eggs between early September and late October. The shell length of hatchlings in one Canadian population ranged from 2.44 to 2.94 cm, but hatchlings as large as 3.1 cm have been reported in the U.S. Like many freshwater turtles, spotted turtles have temperature-dependent sex determination, meaning the sex of the offspring is determined by the incubation temperature of the eggs. For spotted turtles, cooler temperatures produce males, while warmer temperatures produce females.
In Canada, spotted turtles do not reach sexual maturity until they are 10–15 years old. Freshwater turtle eggs, hatchlings and juveniles have low survival rates; less than 5 per cent of the eggs will hatch and survive to adulthood. Once individuals reach adult sizes, however, they have very high survival. The maximum lifespan of spotted turtles in one Canadian population was estimated to be 110 years for females and 65 years for males. Small clutch sizes, delayed maturity, and low survival from egg to adult means that spotted turtle populations grow very slowly, making long adult lifespans necessary to maintain stable populations.
Diet and Predation
Spotted turtles are omnivores and eat various plants and small animals, including leaves, seeds, berries, insects, spiders, slugs, worms, snails, crayfish, tadpoles and carrion (dead animals). They primarily forage and eat in the water. The main predators of adult spotted turtles are mammals, including raccoons, foxes, skunks, otters, mink, coyotes and bears. Bald eagles are also known to prey upon adults. Mammals such as raccoons, foxes, skunks and coyotes are also major predators of spotted turtle nests. Nest predation rates can be very high in areas with a high abundance of these mammalian predators. Hatchlings are eaten by a wide range of animals, including various mammals, wading birds, crows, snakes and snapping turtles.
Since spotted turtles have long lifespans and very slow population growth, losing even a small number of adults each year can cause population declines. This makes any activities that result in the death or removal of adults, such as poaching or the death of turtles on roads, a severe threat to spotted turtle populations. Much of this species’ wetland habitat has already been lost throughout southern Ontario, and ongoing habitat loss and fragmentation continues to threaten the remaining populations. The invasive European common reed (Phragmites australis), which invades shallow-water habitats, is spreading rapidly across southern Ontario and degrading the species’ wetlands habitats (see also Invasive Species in Canada: Plants). Other threats include increased abundance of nest predators (e.g., raccoons) in many human-settled areas, agricultural activities, logging and climate change.
Status and Conservation
Globally, the spotted turtle is listed as endangered by the International Union for Conservation of Nature. It is also listed as endangered under the Canadian Species at Risk Act (SARA) and Ontario’s Endangered Species Act (ESA). These federal and provincial laws provide protection for threatened and endangered species and their habitat, including the spotted turtle. Due to the threat of poaching, it is often necessary to keep the locations of spotted turtle populations confidential. However, this can present unique conservation challenges such as making it difficult for the public to contribute to spotted turtle research, stewardship or recovery programs.