Burrow Collapse as a Potential Stressor on the Gopher Tortoise (Gopherus polyphenus)

The gopher tortoise is a species of concern throughout the Southeast, and is a keystone species throughout its range. It is federally listed as Threatened in part of its range and has been proposed for listing elsewhere. During forest thinning and harvesting, and during military training exercises, tortoise burrows are often accidentally run over. No formal studies of the potential for tortoise injury resulting from burrow collapse had been conducted in the natural environment, however. This research was designed to determine the potential for tortoise injury from the direct crushing of the burrows or loss of life through inability to escape from a collapsed burrow. Forty intentional burrow collapses by heavy equipment were studied. Data were acquired on pre- and post-collapse movement patterns and several general health and physiological measures. No tortoises appeared to have any life-threatening injury, and tortoises normally self-excavated, with excavation intervals ranging from an hour to 85 days. All tortoises remained within a normal home range of their collapsed burrow, resulting in little change in movement patterns after burrow collapse. Changes in home range, number of burrows used, daily movement patterns, or the mean distance moved by the tortoises do not appear significant.