Foraging Behavior and Spacing Patterns of the Lizard Oligosoma grande

Abstract

The grand skink, Oligosoma grande, is a diurnal rock-dwelling lizard from the tussock grass- lands of Central Otago, New Zealand. Foraging behavior, diet, and spacing patterns were examined for two populations of individually marked adults. Adults of both sexes search for arthropod prey using pause- move (=saltatory) searching. Males and females spent the same amount of time moving across outcrops but differed in the characteristics of their searching behavior. Females made more frequent but shorter moves than males. The two sexes also differed in diet Males directed most of their pursuit effort towards large flying insects, but occasionally consumed smaller, easy to capture prey and visited fruiting plants. By con- trast, females fed primarily on the small prey types and plant material. Males and females had home ranges (HR) and core areas (CA) of comparable size and with comparable levels of total neighbor overlap However, the patterns of HR overlap differed between the sexes. Both males and females tended to have greater average HR overlap with male neighbors. Core area overlap was less extensive than HR overlap and some animals concentrated their activity in CAs that were exclusive from those of other lizards. Females appeared to be dominant to males; the most common conspecific interaction was adult females chasing adult males.