1 December 2016 Diet of Roadkilled Western Rattlesnakes (Crotalus oreganus) and Gophersnakes (Pituophis catenifer) in Southern British Columbia
Jillian M McAllister, Jared R Maida
Author Affiliations +

A critical 1st step in understanding the basic ecology of any predator is to delineate their suite of prey species. In this paper we provide data on the diet of 2 threatened snake species in British Columbia, the Western Rattlesnake (Crotalus oreganus) and the Gophersnake (Pituophis catenifer). By dissecting the gastrointestinal tracts of roadkilled specimens, we identified a total of 11 different prey types. Unlike what has been previously reported elsewhere for the 2 species, we found a strikingly high degree of overlap between the diets, as shown through Morisita's similarity index (Ĉ = 0.98). The Deer Mouse (Peromyscus maniculatus) was the most frequently identified prey type for both species, followed by shrews (Sorex spp.). Other prey species consumed by Western Rattlesnakes were approximately even in abundance and in low numbers. Gophersnakes had a wider range of prey consumed at moderate frequencies, including voles (Microtus spp.) and birds. We also detected prey in a relatively high percentage of our specimens, likely due to our method of analyzing roadkills rather than sampling live, free-ranging animals. These prey data contribute a better understanding of the natural history and conservation issues facing these 2 threatened snake species, providing insight into how they coexist in a habitat increasingly destroyed and fragmented by human development.

Jillian M McAllister and Jared R Maida "Diet of Roadkilled Western Rattlesnakes (Crotalus oreganus) and Gophersnakes (Pituophis catenifer) in Southern British Columbia," Northwestern Naturalist 97(3), 181-189, (1 December 2016). https://doi.org/10.1898/NWN15-25.1
Received: 24 July 2015; Accepted: 1 July 2016; Published: 1 December 2016
British Columbia
Crotalus oreganus
gastrointestinal tract analysis
Okanagan Valley
Pituophis catenifer
Get copyright permission
Back to Top