Ontogenetic differences in habitat selection and foraging mode in Chamaeleo chamaekon

Intraspecific competition between individuals can cause differences in food choice, foraging pattern, and habitat selection. We examined whether there are ontogenetic differences in habitat selection and foraging mode in the common chameleon (Chamaeleo chamaeleon). In addition, we checked whether adult presence influenced those factors among juveniles. Habitat selection was monitored by perch height, perch diameter, and plant species on which the chameleons stay overnight. Field observations and experiments reflected significant ontogenetic differences in habitat selection. Adults preferred higher perches and wider stems than juveniles. Significant ontogenetic difference was also found in foraging mode. Juveniles foraged more actively than adults. Adult presence significantly affected foraging mode in juveniles, affecting the intensity of activity and causing changes in behavior. A case of cannibalism in which an adult killed and ate a juvenile was observed during the experiment. Ontogenetic differences in habitat selection and foraging mode between adults and juveniles may reduce both intraspecific competition for food and predation risk of juveniles by adults.