The Herpetological Journal

pp.151-155

Authors: Christopher H. Shewchuk And James D. Austin

Abstract: Dietary habits of the racer, Coluber constrictor mormon, were studied based on stomach and faecal contents from 26 road killed specimens and 297 live animals collected in the field during 1992-1994 in southern British Columbia, Canada. Thirty percent of the specimens examined contained gut contents. Coluber constrictor mormon feeds mainly on insects (91% of prey; Acnd1dae > Gryllidae > Tettigoniidae > Gryllacrididae) and occasionally rodents (7.5% of prey), as well as frogs and snakes (both < I %). There were proportionally more vertebrates in the diets during the early part of the season (April - May). Diet was related to individual attributes, such as size or sex of the snake. Thus, larger individuals - primarily females - were more. likely to . feed on vertebrates, although insects were not absent from the diet of larger individuals. Diet composition (mammals vs. insects only) did not depend upon the method of sampling snakes. This study adds to the growing number of dietary studies on Coluber constrictor that continue to provide insights into the evolutionary ecology of this widespread but poorly-known species.

Keywords: Coluber constrictor, feeding ecology, British Columbia, Canada, diet, food habits