Female Reproductive Ecology of Western Rattlesnakes (Crotalus oreganus) in Southern British Columbia
Eye, Dana M.
Environmental Science Program
Thompson Rivers University
Kamloops, British Columbia, Canada
danaeye03@gmail.com
Skurikhina, Anna
Department of Natural Resource Science
Thompson Rivers University
Kamloops, British Columbia, Canada
Bishop, Christine
Environment and Climate Change Canada
Delta, British Columbia, Canada
Larsen, Karl W.
Department of Natural Resource Sciences
Thompson Rivers University
Kamloops, British Columbia, Canada
klarsen@tru.ca
Female reproductive success, habitat selection and behaviour are all important elements in rattlesnake ecology. In Canada, a large portion of research on the Western Rattlesnake (Crotalus oreganus) has focused heavily on male behaviour (including migration), leaving a large knowledge gap and biasing the development of effective recovery plans. Our study in Osoyoos, BC, is focusing on site selection and movement behaviour by female rattlesnakes during parturition. We are using radio telemetry to track gravid female rattlesnakes (n=15 to date) to their ‘rookery sites’, identified by the cessation of long-distance movements and the adoption of sedentary behaviour. These sites are being compared to random habitat plots using a matched case-control study design. Vegetation cover, temperature data, and additional features are being assessed at three different spatial scales (1 m, 3 m, & 10 m radius plots). To date, we have identified 14 rookery sites and 7 communal rookery sites. The average distance traveled by gravid females from their hibernacula to their rookery sites is 84.7 m (range 7.4 m to 233.2 m, n= 15). Additionally, 12/15 females moved down slope, following parturition, in the opposite direction of their hibernacula. This spring, gravid female rattlesnakes will be radio-tracked at three different sites in BC, in addition to provisioning experiments, to investigate the potential drivers of post-partum rattlesnake movement. Information from this ongoing study will shed insight into a critical phase of the life history of female rattlesnakes in this region.