Chemosensory recognition by males of the Desert Pocket Mouse, Chaetodipus pencillatus to odors of various species of snakes

Abstract

Studies were conducted to assess responses of the Desert Pocket Mouse Chaetodipus pencillatus, to chemosensory cues (treatment odors) associated with three naturally-occurring sympatric snake predators (Crotalus atrox, Pituophis melanoleucas, Elaphe guttata), and a snake that does not feed on mammals (Hypsiglena torquata), as well as an odorless control (water) and pungency control (cologne). Pocket mice were tested in a chamber where they were exposed to various treatments and their locomotor activity and defecation rate were recorded. Locomotor activity and defecation rates were significantly greater for mice exposed to odors associated with snake predators as compared to H. torquata or controls. There was no significant difference in responses of pocket mice to water or cologne treatments. Results suggest that because all test subjects had no prior experience with any of the snake species, their ability to detect and respond to odors associated with these predators must be innate.