Female Reproductive Cycle and Life History Attributes in a Virginia Population of Painted Turtles, Chrysemys picta

Abstract

ABSTRAcr. -Female reproductive cycles and life history attributes were studied over a two-year period in a population of Chrysemys picta picta in central Virginia, U.S.A. Ovarian cycles were phenologically similar between years despite differences in temperature and rainfall. Vitellogenesis began in August and continued, except during brumation, into the following May. Clutches averaging 4.2 eggs were laid mid-May to July and did not differ between years. Females matured at six years of age and plastron lengths of >105 mm. Several females each year produced two clutches, and although second clutches were not significantly different from first clutches, they averaged slightly larger. Clutch size and egg width were positively correlated with female body size. A multiple regression model explained over 89% of clutch size variation with the independent variables plastron length, egg mass, and month. Between-year differences in egg measurements were insignificant. Several recent generalizations about aspects of freshwater turtle life histories are supported by results of this study.