Ecological Correlates of Population and Individual Variation in Antipredator Behavior of Two Species of Desert Lizards

Abstract

Antipredator behavior was measured in four populations of zebra-tailed lizards (Callisaurus draconoides) and two populations of greater earless lizards (Cophosaurus texanus). Lizards were approached in the field, and five measures of wariness were recorded. Callisaurus had significantly greater approach distance and greater final distance than did Cophosaurus. Among populations of Callisaurus, lizards were wariest at the site with the least plant cover. Within populations, air temperature, the directness of the observer's approach, and the lizard's distance to nearest cover when first sighted had significant direct effects on flight behavior based on path analysis. Windiness and time of day had significant direct effects and indirect effects through their relationships with air temperature and distance to cover. Path analysis indicated no one variable with great overall influence on antipredator behavior in these lizards but rather a combined influence of several environmental factors.

Influence of predation pressure on the escape behaviour of Podarcis muralis lizards

“…Some studies have suggested that vegetation coverage level could influence the escape behaviour of lizards, as specimens which were in very well-covered places showed a closer flight initiation distance than those which were in more open sites (Bulova, 1994;Martín and López, 1995;Snell et al, 1988). However, our results differed from these suggestions.…”

“…The distance to a safe refuge can be used as a measure of the risk that lizards take, because the risk of capture is higher for prey that are farther from the refuge (Bulova, 1994;Blázquez et al, 1997;Cooper, 1997b). Lizards from the two populations showed similar distances to the nearest potential refuge, but lizards from the low elevation population were more wary than the high elevation ones.…”

“…Our results indicate that lizards on Valnera Mountains had longer flight initiation distances when the ambient temperatures were higher. Perhaps, costs of refuge use can also affect escape decisions, and lizards may be considering the loss of heating opportunities in deciding when to escape (Bulova, 1994;Cooper, 2000;Martín and López, 2000). On the contrary, in the low altitude population located in Cieza Mountains, ambient temperatures were not significantly correlated with flight initiation distances.…”

“…I observed two types of escape tactics: (1) some lizards made a short flight to a hiding place, and (2) other animals made a short flight without hiding in any refuge. I gathered quantitative data on two components of the lizard's escape behaviour: (1) flight initiation distance, the distance from the lizard that the lizard allowed the observer to approach before fleeing, and (2) distance fled, the total distance fled in one continuous movement from the lizard's initial position until hiding or stopping at a safety distance (Bulova, 1994;Cooper, 1997b).…”

“…In lizards, predator-prey interactions can be influenced by habitat selection (Bulova, 1994;Martín and López, 1995;Downes and Shine, 1998). However, as Smith and Ballinger (2001) suggested, few studies have actually estimated predation risk or differences in predation risk in different habitats (but see Brown and Ruby, 1977;Parker, 1994;Smith, 1996).…”