Montana Field Guide

Painted Turtle - Chrysemys picta

The upper shell is olive to black, with the edges of shields (plates making up the shell) bordered with yellow. The head, neck, and legs are marked with yellow lines, and a red spot appears behind the eye. The lower shell is brightly colored with red and yellow. Females may reach 9 inches in upper shell length, but males seldom reach 7 inches. Males have much longer front claws than females, and the vent is situated farther from the edge of the shell.

Montana Range

Painted turtles are found in lakes, ponds, reservoirs, and sloughs that contain some shallow water areas and a soft bottom; also river backwaters and oxbows with little current. They often use logs and rocks for basking. Painted turtles hibernate in bottom mud from early October to mid- or late April. They reproduce at 4 to 8 years of age, depending on climate (later in northern latitudes). Six to 20 leathery eggs are laid in nests excavated in gravel or sand. Food items include aquatic vegetation, frogs, tadpoles, small fish, and a variety of invertebrates (FWP). Found in wide variety of waterbodies, incl. glacial lakes (Franz 1971); but not found in oligotropic mtn lakes above 3363 ft. in Mission Mtns (Brunson and Demaree 1951). Nest on S facing grassy slopes in S Canada (MacCracken et al. 1983).

Ease of capture and size are major influences on what prey is taken. In S Saskatchewan, turtles preferred animal food (>87% by vol.) over abundant vegetation. Decapoda greatly preferred, then amphipod, gastropod, insect larvae. Plant material was a significant food item (21-61%) in some turtles that had stopped growing. Food quality (animal vs. plant) and quantity may influence reproductive potential (MacCracken et al. 1983).

In SW Canada: density 11.1/ha. Hatchling survival 19.7 (0- 52%). A 1995 mortality study (Fowle 1996) reported most DOR turtles occurring from late May to mid July and consisting of 43% adult males, 26% adult females, and 31% of unknown sex, including juveniles. Densities of adult turtles were positively correlated with pond distance from the highway, and proportionally more juveniles and fewer adults were found at ponds closest to the highway, implying that roadkill mortality may be killing proportionally more adults (Fowle 1996).

A 1995 Mission Valley, MT, study (Fowle 1996) reported gravid females ranging from 7 to 17 in age, with smallest gravid female plastron lengths/widths of 166 and 82 mm for 11- and 9-year olds, respectively. The youngest males with secondary sex characteristics were 2 years old, with minimum plastron lengths/widths of 33 and 49 mm for 4- and 3-year olds, respectively (Fowle 1996). Males sexually mature at plastron length 100 mm (4-5 years); females at 140-150 mm (5-6 years). Clutch size is 20 (in southern Canada) to 10 (in Wisconsin & Minnesota) (Christiansen and Moll 1973). In Wisconsin, 50% of females laid two clutches and nested from June to mid-July. Eggs may overwinter (Ernst 1972).