TERRAIN USE AND MOVEMENT OF A RELOCATED DESERT TORTOISES: FEASIBILITY OF RELOCATING TORTOISES AS A MITIGATION TOOL

Patrick Ross and Edward Mullen, Science Applications International Corporation, Santa Barbara, CA.

Seventy-two desert tortoises were removed from a section (1-square mile) of habitat in Cantil, California, on the western edge of the Mojave Desert in 1989. Tortoises were relocated to a diagonally adjacent section of fenced habitat in the Desert Tortoise Natural Area. The relocated tortoises and a similar population of coexisting unrelocated tortoises (residents) were monitored over the next three years to assess the effects of relocation on tortoise behavior, health, and survival. The locations of tortoises recorded during monthly visits were used to assess the effect of relocation on terrain use and movement. In general, all tortoises were found in areas near the fenced perimeter more often than would be expected by chance. In addition, relocated tortoises were found in areas of the study plot near the site of their original capture more often than would be expected by chance. Year-to-year and sexual differences in the these results will also be discussed.