Pointing gesture in a bird- merely instrumental or a cognitively complex behavior?

Abstract

Gestures, particularly pointing, are regarded as important pre-speech acts. Intentional and referential pointing has been shown previously in humans and apes but not in songbirds, although some avian species show cognitive abilities rivaling those of apes, and their brain structures and functions show putative preconditions for referential gestural signaling (i.e. mirror neurons, links of vocal learning nuclei to discrete brain areas active during limb and body movements). The results reported are based on trials testing predator detection and responses to a taxidermic model of a wedge-tailed eagle by Australian magpies 'Gymnorhina tibicen'. Magpies were subjected to three conditions of finding this model in their territory (open, sheltered and hidden). In the sheltered and hidden conditions, the discoverer simultaneously engaged in alarm calls and beak pointing, a behavior that has not been described previously. Other group members at once assembled and, after watching the first bird, adopted the same posture by pointing to the location of the intruder. The question is whether beak and body movements orienting towards important stimuli or events are instances of arousal, imitation or intentional communication. The latter presupposes that onlookers interpret the signal and respond by altering their own behavior appropriate to the original stimulus and not merely by imitating the first signaler. Evidence presented here indicates that the act of pointing may well be a complex cognitive behavior, i.e., an intentional and referential signal, showing that pointing is not limited to having hands and arms.