The effect of perch diameter on escape behaviour of Anolis lizards: Laboratory predictions and field tests

This study investigated whether the escape behaviour of lizard species could be predicted by knowledge of their functional capabilities. In the laboratory, the effect of perch support diameter on sprinting and jumping ability was measured in five species of Anolis lizards. In all species, sprint speed declined with decreasing perch diameter, but decreased perch diameter had little effect on jumping ability. The escape behaviour of a lizard on a particular-sized support in nature was then evaluated as a function of the lizard's sprinting and jumping capabilities. As diameter decreased, lizards in all but one species tended to escape by jumping more frequently because jumping ability is less affected by diameter than is sprinting ability. It was also predicted that species in which running ability declines greatly as diameter decreases should switch to escape by jumping more often than species that experience less of a decline in running ability. This prediction was not confirmed. Consequently, functional capabilities play a role in determining escape behaviour in Anolis lizards, but other factors may be important as well.