Movements and hibernation sites of overwintering painted turtles in southern Ontario

Selection of hibernation sites and overwintering movements were examined in a small population of painted turtles (Chrysemys picta), in a pond near Lakefield, Ontario. Turtles emerged from overwintering sites where the water depth, sediment depth, and temperature did not differ from the average for the pond, but were less variable. Turtles overwintered in areas with water depths from 0.2 to 0.48 m, sediment depths from 0.5 to 0.95 m, and sediment temperatures from 3 to 6 °C. Contrary to prediction, turtles did not overwinter in the regions of the pond that were the first to melt in the spring. Four turtles tagged with temperature-sensitive transmitters and followed over the winter maintained carapace surface temperatures between 4 and 6 °C during the period of ice cover. Movements of turtles continued after ice cover but virtually ended once the water became anoxic. All turtles were buried in the mud from January to spring emergence in March.