TRANSLOCATION AS A NONLETHAL ALTERNATIVE FOR MANAGING CALIFORNIA GROUND-SQUIRRELS

To evaluate the efficacy of translocation as a nonlethal management al ternative, we determined trapability, post-release survival, site fide lity and homing ability of experimentally translocated California grou nd squirrels (Spermophilus beecheyl). Trapability of squirrels was low (0.04 captures/trap-day.). Most squirrels (71-79%) survived until gre ater than or equal to 18 days after translocation; mortality was highe st shortly after release, and was attributed mostly to predation. Of t hose squirrels that survived but did not return home, 85% established a new home range, but most settled away from the release site. Homing success decreased with translocation distance. Our data do not support the hypothesis that homing results from navigation, but they do suppo rt the hypothesis that homing results from piloting when squirrels are inside their area of familiarity, perhaps extended by visual detectio n of distant landmarks, and random search when outside. Translocation probably is infeasible for control of squirrels over large areas becau se of low trapability, but shows potential for smaller localities. Squ irrels, however, must be translocated far enough (ca. 1,500 m) to prev ent homing, and lack of fidelity to the release site may result in squ irrels settling in undesirable locations.