Rattlesnakes on the Edge: The Effect of Long- and Short-Distance Translocation on the Movement Patte

Corbit, Aaron G.

Hayes, William K.

Department of Earth and Biological Sciences

Loma Linda University

Loma Linda, CA, 92350 USA

Mitigation of human-rattlesnake conflict generally involves euthanizing or translocating the offending rattlesnake. Of these, translocation is generally considered more humane, especially by the general public. However, it may significantly impact the individual snake that is translocated. We studied the effect of short-distance translocation (SDT) and long-distance translocation (LDT) on Red Diamond Rattlesnakes (Crotalus ruber) located near residential development in Southern California. Depending on measure (minimum convex polygon, local convex hull, range length), activity ranges of LDT snakes were 38.6–67.1% larger than those of SDT snakes, which, in turn, had activity ranges that were 77.0–152.9% larger than those of non-translocated (NT) snakes. Snakes moved closer to human modified areas during the summer, and were translocated most often during that season at the behest of property owners. Analysis using Cox regression revealed that both SDT and LDT snakes were more likely to move into human-modified areas subsequent to translocation than NT snakes. For translocated snakes, every 1 m increase in distance moved resulted in a 1.2% decreased risk of moving into a human-modified area, and a 1.5% decreased risk of returning to the site of capture. We found no differences in the survival rate between translocated snakes (LDT an1d SDT) and NT snakes. Our findings suggest that LDT of nuisance snakes may be a viable option for at least some rattlesnake species. To reduce confusion arising from different meanings of the terms SDT and LDT among different studies, we propose standardizing the terms for distance of movement as alpha- (within the individual's home range), beta- (within the local deme), gamma- (beyond the local deme), and delta-translocation (to regions unoccupied by the species, including inter-continental).