Knowing what venomous snakes eat is relevant both to their conservation and to understanding the functional diversity of their venom proteins. We used fecal samples to quantify the diet of Eastern Massasauga Rattlesnakes (Sistrurus catenatus catenatus) in Ontario and Ohio. Small mammals comprised almost the entire diet of both populations, collectively comprising 13 species, five of which were common to both populations. Consistent with their habitat use, Ontario snakes ate both forest and field mammals. The unexpected occurrence of Eastern Chipmunks (Tamias striatus) in the Ohio samples suggested that those snakes either moved out of the fields in which they were caught to feed, or encountered chipmunks dispersing along fencerows. Large snakes did not drop small prey species from their diets and the occurrence of large prey species in diets indicates that juvenile small mammals are important prey. Limited effects of snake size on diet composition suggest that ontogenetic shifts in venom composition are unlikely to occur in the Eastern Massasauga. The similarity of diets between populations makes it unlikely that populations differ in venom composition because of local adaptation of venom proteins to different suites of prey.
ASJC Scopus subject areas
- Animal Science and Zoology
- Ecology, Evolution, Behavior and Systematics