Sand-diving as an escape tactic in the lizard Meroles anchietae

Abstract

Risk assessment and behavioral responses to predation can depend on demographic and environmental factors. We studied the escape behavior of the sand-diving lizard Meroles anchietae in the Namib Desert, using simulated predator approaches and measuring latency to burying in sand. Lizards showed a clear preference for burying on a slipface. Flight initiation distance was largely influenced by the starting distance separating the lizard and pursuer, and whether the animal was initially sighted on or off a slipface. In general, longer starting distances were associated with longer flight initiation distances. The total flight distance covered by lizards before burying was inversely related to body size, and positively related to initial distance from a slipface crest. Distance from a slipface crest was associated with increased total flight distance, most dramatically for those initially sighted on a dune slipface. Even when shelter is ubiquitous, sand-dive patterns depend on location on a dune and body condition.