Te. Graham et al., Dispersal from and fidelity to a hibernaculum in a northern Vermont population of Common Map Turtles, Graptemys geographica, CAN FIELD-N, 114(3), 2000, pp. 405-408
Adult female Common Map Turtles, Graptemys geographica, ranging in carapace
length from 160-260 mm were tracked with sonic equipment from November 199
7 to November 1998. Seven of the 15 turtles tagged initially in 1997 return
ed to the same river hibernaculum in 1998. SCUBA observation demonstrated t
hat hibernating females clustered together shell to shell in small and larg
e groups often piled upon one another. They wintered fully exposed (unburie
d) but frequently positioned themselves against bottom debris (rocks, ledge
outcrops, submerged logs). Ice covered the river from December through Mar
ch. Zn April, when the ice had thawed, the animals emigrated to their summe
r home ranges. Range length for 6 females was 1.5 - 8.0 km along the river
course. Total movements outside the hibernaculum ranged from 3.1 - 15.4 km.
Some individuals moved downstream to Lake Champlain (2.7 km) and along the
lakeshore as much as 2.2 km from the river's mouth. One individual moved 5
.8 km upstream, then headed 9.5 km downstream to the lake before returning
to the hibernaculum.