Habitat Preferences and Home Range Size in a Colubrid Snake

摘要

Effective wildlife conservation plans should consider both the habitat needs and spatial requirements of the species in question. Studies that focus on the correlation between the habitat preferences and movement patterns of wildlife, particularly snakes, are uncommon. In this study, the authors attempted to determine how habitat preferences or quality influenced movement patterns of snakes. To answer this question, they used habitat preference or avoidance information obtained for Bullsnakes (Pituophis catenifer sayi) from 2003-2005 at a site in the upper-midwestern United States and compared it to minimum convex polygon estimates of home range size derived from data on radio-tracked snakes. They employed Geographical Information Systems to model the amount of preferred (open bluff faces) and avoided (agricultural fields and closed canopy forests) habitats within each estimated home range and compared them via multiple linear regression. They also tested the influence of gender, length and weight on home range size. The results of this study indicated that, among the investigated potential correlates, amount of avoided habitat was the most significant indicator of home range size. More specifically, home range size increased with amount of avoided habitat within the home range. As bullsnakes are large snakes, they are particularly susceptible to road mortality; therefore, fragmentation of suitable habitat forces snakes to wander further in the search for suitable habitat, exposing them to greater risk. In a broader context, this finding supports the hypothesis that habitat quality has an impact on wildlife movement patterns, and the relationship between habitat needs and spatial requirements should be considered when conserving or managing species.