Research on pied babblers has provided the first evidence of teaching behaviour in an avian species. Pied babblers teach their young by giving a specific purr call each time they deliver food. Young learn to associate this call with food and reach out of the nest each time they hear it. Adults exploit this association to encourage young to fledge by giving the purr call at a distance from the nest, enticing young to follow them. Post-fledging, adults continue to use the call to encourage young to move between foraging areas or away from predators. This call is also used to recruit independent fledglings to a rich foraging site, and may thus provide young with information on where to forage to locate rich food sources.