Chrysemys picta

Shell hard, somewhat flattened; bright yellow lines on head and limbs; lower shell orange or reddish, with conspicuous dark markings in juveniles; upper shell often with narrow yellow lines (reduced in larger individuals), less often with dark reticulation; upper jaw notched at tip; maximum upper shell length of female about 25 cm, rarely more than 21 cm (males are much smaller). Mature male: vent located beyond rear edge of upper shell with tail extended; fingernails very long; lower shell not concave. Mature female: vent at or inside rear edge of upper shell with tail extended; fingernails not especially long. Juvenile: as in adult female, with a deep crease across abdominal shields of lower shell. Hatchling: upper shell keeled; lower shell vivid orange/red, with a central dark figure having a sinuous outer edge; upper shell length 19-28 mm (average 23-24 mm). Eggs: elliptical, whitish, smooth surface with small pores; shell initially flexible, then becomes more rigid, 21-36 mm x 15-21 mm (mostly about 29-33 x 18-19 mm). Source: Hammerson (1999).

This species lives in slow-moving, shallow waters with soft bottoms such as rivers, streams, marshes, swamps, ponds, lakes, and reservoirs (Ernst and Lovich 2009). Aquatic vegetation and abundant basking sites are important habitat components (Ernst and Lovich 2009). They may colonize seasonally flooded areas near permanent water (Ernst and Lovich 2009). Nesting occurs in soft soil up to several hundred meters from water (Christens and Bider 1987, Congdon and Gatten 1989, Ernst and Lovich 2009). Some hatchlings remain in the nest in winter and emerge in spring (Packard and Packard 1995, Ernst and Lovich 2009). Adults estivate in water (Ernst and Lovich 2009).

Home ranges vary drastically. Lakes, ponds, and marsh populations generally have the smallest home ranges and the largest home ranges generally occur in river or creek systems (Ernst and Lovich 2009). Population densities vary widely with the greatest densities, up to several hundred individuals per hectare, occurring in lakes, ponds, and marshes, while river or creek systems generally have the lowest population densities (Ernst and Lovich 2009). Survivorship of eggs and hatchlings is generally below 20% (Christens and Bider 1987, Lindeman 1991, Ernst and Lovich 2009). Survivorship rates increase with age, with adults generally having survivorship rates above 50% and many reports are above 90% (Mitchell 1988, Frazer et al. 1991, Iverson and Smith 1993, Ernst and Lovich 2009). See Iverson (1991) for a compilation of survivorship data on eggs and juveniles. In Nebraska, some females apparently survived beyond 30 years (Iverson and Smith 1993).

Most nesting occurs between late May and early July, perhaps earlier in the south (Ernst and Lovich 2009). Females dig nests in soft soil in open areas up to several hundred meters from water (Christens and Bider 1987, Congdon and Gatten 1989, Ernst and Lovich 2009). Individual females can produce up to five clutches per season (Ernst and Lovich 2009). Clutch size ranges from 1-23 eggs, with the largest subspecies, C. p. bellii, producing the largest clutch sizes and the smallest, C. p. picta, producing the smallest clutch sizes (Ernst and Lovich 2009). Females reach sexual maturity in as little as 5 years in southern parts of its range and as much as 10 years in northern parts of its range (Ernst and Lovich 2009). Males mature at younger ages (Frazzer et al. 1993, Ernst and Lovich 2009). Hatchlings usually remain in the nest in winter, tolerating freezing temperatures, and emerge in spring (Ernst and Lovich 2009).