S. Downes et R. Shine, HEAT, SAFETY OR SOLITUDE - USING HABITAT SELECTION EXPERIMENTS TO IDENTIFY A LIZARDS PRIORITIES, Animal behaviour, 55, 1998, pp. 1387-1396
Laboratory experiments with a rock-dwelling nocturnal gecko, Oedura le
suerii, showed that retreat-site selection (and other behaviours) are
affected by the interplay between thermal benefits, social advantages
and avoidance of predators. Velvet geckos were highly selective in hab
itat choice: they preferred artificial retreat-sites that mimic the th
ermal properties of natural rocks in full sun rather than those that m
imic rocks in full shade. mature male geckos rarely shared retreat-sit
es with other adult males: and these lizards strongly avoided retreat-
sites covered with the scent of a natural predator (the broadheaded sn
ake, Hoplocephalus bungaroides), After documenting these preferences?
we carried out additional trials in which two or more of these factors
co-occurred, as is often the case in nature. Social dominance interac
ted with thermal benefits in determining retreat-site selection, with
smaller (subordinate) males forced to use cooler retreat-sites when la
rger (dominant) males were present. Avoidance of predators was a highe
r priority than thermoregulation: the lizards would forego a warmer re
treat-site with predator scent in favour of a cooler, unscented one. T
here was also an interplay between social dominance and predator scent
: smaller males were forced to use either predator-scented retreat-sit
es or no retreat-site when larger males were present. General activity
levels, and the frequencies of specific behavioural acts, also shifte
d in response to social and predator-scent cues. Our study emphasizes
the complexity of habitat-selection behaviour in these lizards, and cl
arifies the criteria used in retreat-site selection when (as is common
ly the case) the animal must choose between conflicting priorities. (C
) 1998 The Association for the Study of Animal Behaviour.