Sex-specific antipredator response to auditory cues in the black spiny-tailed iguana

摘要

The selective pressures exerted by predation can have considerable influence on the behavior of prey species across a wide range of taxa. Within a species, this force may differ between the sexes, leading to sex-specific behavioral responses to predators. We tested whether the black spiny-tailed iguana Ctenosaura similis is able to use auditory cues to detect an avian predator and whether antipredator responses differ in a sex-dependent fashion. We conducted behavioral assays in which a food item was used as bait while iguanas were subjected to a recording of a Harris's hawk or white noise as a control. We found that a significantly greater percentage of individuals of either sex responded to the hawk call than to the white noise. We also found that a significantly greater percentage of females than males responded to either sound. These results suggest that not only do black spiny-tailed iguanas incorporate auditory cues into predator detection, but that antipredator behavioral responses differ between the sexes as well. Such sex-specific behaviors can be attributed to morphological and endocrine differences between male and female iguanas. These findings may also lend insight into how behavior can influence the evolution of sexual dimorphism within a species.