Data from: Watch out where you sleep: nocturnal sleeping behaviour of Bay Island lizards

Sleeping exposes lizards to predation. Therefore, sleeping strategies must
be directed towards avoiding predation and might vary among syntopic
species. We studied sleeping site characteristics of two syntopic,
congeneric lizards—the Bay Island forest lizard, Coryphophylax
subcristatus and the short-tailed Bay Island lizard, C. brevicaudus and
evaluated inter-specific differences. We measured structural,
microclimatic and potential predator avoidance at the sleeping perches of
386 C. subcristatus and 185 C. brevicaudus. Contrary to our expectation,
we found similar perch use in both species. The lizards appeared to use
narrow girth perch plants and accessed perches by moving both vertically
and horizontally. Most lizards slept on leaves, with their heads directed
towards the potential path of a predator approaching from the plant base.
There was no inter-specific competition in the choices of sleeping
perches. These choices indicate an anti-predator strategy involving both
tactile and visual cues. This study provides insight into a rarely studied
behaviour in reptiles and its adaptive significance.