Effects of disturbance on the Northern Pacific Rattlesnake (Crotalus Oreganus Oreganus) in British Columbia

The indirect effects of anthropogenic disturbances on wildlife are relatively difficult to detect, much less study, yet understanding these more subtle influences are particularly critical for the conservation of species-at-risk. In this study, I used radio-telemetry and mark-recapture methods to investigate the indirect effects of human disturbance and habitat development on the body characteristics, behaviour, and spatial ecology of a population of rattlesnakes (a threatened species) in Osoyoos, British Columbia. I collected data in 2010 and 2011 to augment a data set spanning 2002 to 2012. Individuals in highly disturbed landscapes had lower body condition than snakes in other areas, and lost body weight over the foraging season. Strong trends in spatial ecology parameters across disturbance gradients were not apparent, although snakes in disturbed sites tended to have smaller core areas, shorter range lengths, and took a greater number of days to travel a given distance than snakes in less-disturbed habitat. No major differences were observed in snake behaviour, exposure risk, or other spatial ecology parameters among habitats under different disturbance pressures. Wildlife managers can apply the results of this study to put recovery goals into action for the Northern Pacific Rattlesnake. The findings also contribute to our understanding of how wildlife may be impacted in discrete ways within disturbed habitat, and highlight the importance of using multiple indicators to assess stability of animal populations.