Avian drop-catch play: a review

摘要

Repeated dropping and catching of non-food objects by birds in flight has been recorded in over 25 species, of which raptors, gulls and corvids are the most well-represented groups. Drop-catching of prey objects has also been recorded. Anecdotal reports and quantitative studies are reviewed here. The evidence suggests that, for most species and in most situations, the behaviour is play. It may also serve the adaptive functions of physical training and practice of motor skills, among others. A few reports indicate that drop-catching might sometimes be used in courtship display, but more evidence is needed. In hirundines, the behaviour may differ from that in larger species in motivation and function.