Site familiarity affects antipredator behavior of the amphisbaenianBlanus cinereus

Abstract

Morphological adaptations of amphisbaenians to fossorial life might affect their antipredator-behavior decisions. Amphisbaenians exposed on the soil surface by a predator can escape by burrowing immediately or by using alternative defensive behaviors on the soil surface, and should decide where to burrow in order to return to their home range. We simulated in the laboratory predatory attacks toward individual amphisbaenians (Blanus cinereus), and examined whether their antipredator and burrowing responses were affected by site familiarity (familiar versus unfamiliar substrate) and their internal state (i.e., body temperature and associated burrowing performance). Amphisbaenians showed significantly longer episodes of alternative antipredator behaviors on the soil surface (coiling and still) when the temperature was low. Before starting to burrow in unfamiliar substrates, individuals emitted numerous tongue flicks and moved for significantly longer periods of time than when on familiar substrates, independently of temperature. In contrast, in their own cages, with familiar substrates, amphisbaenians performed only a few tongue flicks before starting to burrow. Subsequently, the time spent burrowing was significantly longer when the temperature was low or amphisbaenians were on an unfamiliar substrate. These results suggest that amphisbaenians are able to recognize their own home range by chemosensory cues and that they are able to use this information when deciding where to burrow to escape from potential predators.