Meeting Abstract
Adult animals can influence the behavior of juveniles in many different ways (e.g., through parental care, competition, risk of cannibalism). Although research has suggested some juvenile behaviors are influenced by competition between age classes, few are experimental, and thus, cannot unambiguously identify causal factors that generate variation in juvenile behavior. In addition, whereas competition influences many traits, it is unclear how competition might influence how individuals orient themselves in their environment (i.e., the direction an animal chooses to face), which may be important for prey and predator detection and thermoregulation. To determine if threats invoked by competitors/predators influence orientation of juveniles, we altered the density of adult male Anolis sagrei in mesh enclosures to examine how juveniles position themselves in their environment. We found that juveniles decreased horizontal orientation when an adult male was present, and did so more rapidly, and increased upward orientation, when three adult males were present. Given that adult A. sagrei are competitors with and predators of juveniles, these changes in orientation may reduce juvenile vulnerability and increase their ability to monitor adult behavior. In addition, juveniles increased upward orientation and decreased downward orientation at night compared to daytime observations. Interestingly, juveniles also strongly shifted to face the trunks of trees at night when perched on branches. These findings provide novel insight into the factors that influence how animals position themselves within their environment.
