Fruit Feeding Behavior of a Chameleon Furcifer oustaleti: Comparison with Insect Foraging Tactics

Abstract

Because they possess a highly unique long and projective tongue, chameleons have been viewed as strictly insectivorous and considered to use a specific tongue projection method in every feeding event. I report behavioral observations on fruit feeding by Furcifer oustaleti in the field as the first evidence of spontaneous feeding attempts on plant material by wild chameleons. Also, I present results of a feeding experiment to examine differences in feeding on fruits and insects. When chameleons fed on small fruits, most individuals directly picked up them with the mouth at short range, whereas chameleons almost always used tongue projection from a distance to capture small aerial insects. Such alternative feeding tactics occurred within individuals exposed to both foods over a short interval. These results suggest that chameleons discriminate food types to perform the appropriate feeding tactic to efficiently consume different types of food. When chameleons used the direct pickup tactic for fruit in the experiment, the tongue contacted the food item before the jaws did, suggesting that the chameleons have retained lingual prehension, the typical motor pattern of other iguanian lizards.