Population Dynamics and Activity Cycles of Chrysemys picta in Southeastern Pennsylvania

Abstract

The daily and annual activity cycles, reproductive potential, population dynamics, and social relationships of the painted turtle, Chrysemys picta, in southeastern Pennsylvania are presented and comparisons with other population studies on this species and other turtles are made. Chrysemys picta was active only during the daylight hours, foraging for food during the late morning and late afternoon hours and basking at other times. The turtles were active as long as the water temperature remained above 10 C. Most were dormant from late October through March, but always some were active. Mating occurred from late April to mid-June, and nesting occurred during June and July. The mean number of eggs per clutch was 4.73 and the realized reproductive potential was 2.6 young per clutch. The density of turtles was estimated at 239 per acre. The adult sex ration was 1:1 and the juvenile to adult ratio 1:4. The rate of turnover in the population was estimated to be approximately 51 per cent with most mortality occurring in the smaller size-