Variation in Escape Behavior among Individuals of the Striped Plateau Lizard Sceloporus virgatus May Reflect Differences in Boldness

Abstract

Individual differences may affect risk taking (boldness) in antipredatory behavior. I examined individual differences of the lizard Sceloporus virgatus in flight initiation distance (predator-prey distance when escape begins), distance fled, and hiding time (refuge entry until emergence). Positive correlations between repeated measures of flight initiation distance and distance fled showed that individuals differed reliably in each variable, demonstrating individual differences in boldness over intervals of a few minutes to a day or longer, but correlations of hiding times between trials were context-specific. Hiding times were correlated for different speeds and directnesses of approach and predator proximity but not for identical approaches or trials differing in presence of food outside refuge. Independence of repeated hiding times might indicate that assessed risk varied between trials because of uncontrolled differences in approaches that elicited immergence or costs of hiding. Independence of hiding times with food present or absent suggests that differences in nutritional state affected hiding differently when food was present or that boldness is context-specific. Contrary to previous findings for S. virgatus, distance fled and flight initiation distance were unrelated, presumably because the relationship is weak, and possibly because sample sizes were small and uncontrolled distance to refuge and direction fled obscured a relationship.