A Test of Philopatry by Common Musk Turtles

We tested philopatry by common musk turtles Sternotherus odoratus in a Virginia lake for 9 wk during summer 2003. Using unbaited crab pots, 10 trapping sites were established in the littoral zone around the lake perimeter and pots were sampled daily, yielding 560 turtle captures. Musk turtles trapped at the two sites separated by the greatest distance (1.1 km) were marked and released at the opposite site; turtles captured at the eight sites in-between were marked and released at the capture site. Of 287 captures of turtles released at their capture site, 57 were recaptured and 43 of these were at the original capture site. Of 140 captures of turtles displaced 1.1 km, 76 were recaptured and 15 of these were turtles that returned to their site of original capture. Turtles moved significantly more once they had been displaced, and males moved more frequently, but not over longer distances than females. These data indicate that S. odoratus is capable of homing and that site fidelity is exhibited by both male and female turtles. In a lake where the ratio of male:female turtles is approximately 1:1, the occurrence of philopatry is consistent with turtles having discrete home ranges.