Painted Turtle. Chrysemys picta

Description: Carapace length 60-250 mm. Carapace low, smooth and unkeeled; oval in outline. Rear of carapace with a smooth border. Hind feet strongly webbed. Carapace generally olive, brown or black, with contrasting olive, yellow or red borders along the front edge of the shields. Yellow lines on the head and limbs. A red bar or blotch behind the eye. Plastron usually marked with red, and having a dark central patch that sends extensions outward between the scutes.

Variation: Plastron red or orange, with well-pronounced dark markings. Males much smaller than females, with very elongate claws on the front feet and a slightly concave plastron. The vent is more distally positioned on the tail in males and lies outside the carapace margin. Hatchlings have a more rounded carapace with a middorsal keel. Hatchling carapace length is about 25 mm. Males mature at about four years of age, females at five.

Natural history: Aquatic and generally diurnal. Usually found in association with ponds, lakes, streams, ditches or marshes with quiet waters, muddy or sandy bottoms and abundant aquatic plants. Younger individuals occupy shallower water. Frequently bask on logs, rocks or banks near water. Under conditions of high density or high temperature Chrysemys may show aggressive behaviour towards conspecifics at basking sites. It hibernates in winter by burrowing into the mud beneath the water. These turtles may supercool, allowing them to survive temperatures well below freezing, but hatchlings can only survive brief periods of freezing of their bodily fluids. In appropriate conditions, with water-binding agents in the soil, painted turtles in nests can supercool to -17°C or more before spontaneously freezing. In Alberta, it probably does not emerge from hibernation until April. It eats insects, molluscs, earthworms, fish, frogs, tadpoles, aquatic plants and carrion. It may move extensively on land between bodies of water, or it may be restricted to a single body. The painted turtle is preyed upon by small carnivores at all stages of its life. It may also be parasitized by leeches. Individuals may reach an age of forty years.

Reproduction: Lays one or two clutches of eggs from late May through late summer. Mating occurs in the water. Males may be aggressive at that time. The male strokes the female with its elongate claws. Pre-mating courtship usually lasts five to fifteen minutes. Nesting occurs on land, and this usually begins in June. The female digs a nest in sandy or friable soil, near water. Females may carefully select their site of oviposition in order to manipulate the thermal regime of the nest. This is of special significance because painted turtles have temperature-dependent sex determination. Two to twenty eggs are laid. These may be up to 35 x 18 mm. The female covers the nest. The young may overwinter in the nest after hatching.

Distribution: In Alberta, this species occurs naturally only along the Milk River drainage. Localities in the Cypress Hills, Banff National Park, Edmonton and Hines Creek may be introductions. Extralimitally, it is widespread from Vancouver Island (probably introduced), southwestern coastal B.C. and the Columbia River Valley to the central Gulf coast and the Atlantic coast from North Carolina to Nova Scotia. It is absent from the extreme southeastern United States and much of the west.

Conservation status: Although details of the Milk River population are unknown, the very restricted range of this turtle in Alberta makes it of special conservation concern.

Remarks: Four subspecies are recognized. Chrysemys picta belli is the Alberta subspecies. It occurs as far east as central Ontario, northern Michigan, central Wisconsin, western Illinois and northern Missouri. This turtle has been extensively introduced as it is commonly kept as a pet and often released back into the wild. Probably at least some of the introduced populations are viable. Pattern of the carapace may be obscured in some animals by a growth of algae that peaks in density in the summer.

Significant references: Attaway et al. 1998; Beall and Privatera 1973; Bennett et al. 1970; Bishop and Schmidt 1931; Black 1970b; Breitenbach et al. 1984; Cagle 1954; Clark and Chandler, 1992; Congdon and Tinkle 1982; Congdon et al. 1992; Costanzo et al. 1998; Ernst 1971a, b; Ernst and Barbour 1972; Frazer et al. 1991; Froese and Burghardt 1975; Gibbons 1967a, b, 1968a, b, c, 1969; Hammer 1969; Hartweg 1946; Jackson and Ultsch 1982; Janzen 1994; Jones and Milsom 1979; Knight and Gibbons 1968; Lefevre and Brooks 1995; Legler 1954; Lewin 1963b; Lovich 1988; MacCulloch 1981; Milsom and Chan 1986; Milsom and Jones 1980; Mitchell 1983,1985a, b; Moll 1973; Musacchia 1959; Paukstis and Shuman 1989; Rogers and Jellison 1942; Schueler 1983; Sexton 1958, 1959a, b; Sievert et al. 1988; Taylor and Nol 1989; Tinkle et al. 1981; Ultsch and Jackson 1982; Ward 1984; Wilbur 1975.