Abstract

Eleven Varanus caudolineatus, a small Western Australian varanid, were tracked for up to 18 days by means of a radioactive tracer (22*Na). The lizards foraged extensively on the ground and used trees as a safe refuge when resting. They were found most frequently in hollows of dead, standing trees, but they were also found in live trees, and in dead trees and stumps lying on the ground. Upon release after capture the lizards moved up to 159m, remaining in one tree for 1-15 days (mean 2.93 days) before moving a mean distance of 33.9m to another tree or a pit-trap. Most of the foraging activity occurred in late morning or early afternoon, when the ambient temperatures were near their peak. The movement of lizards from 'resident' trees was significantly positively correlated with daily maximum temperatures (30-45.5 degrees C).