Influence of Social Behaviour on Prey-catching in Barn Owls

Young Barn Owls showed no response to prey in the presence of the feeding male; and an Owl reared in isolation showed no response in the presence of the human nurse. Rather, their behaviour consisted of intensive begging and attempts to obtain prey from other Owls. The young delayed independent foraging until the parents stopped feeding them. The role of parents and juveniles in the disbandment of family is discussed. Adult and young Barn Owls protected their prey but also stole prey from other Owls. The Owls mainly defended their prey by Mantling (covering the prey with the wings) or ritualized Mantling (spreading their wings while keeping prey in the beak), mostly combined with feather ruffling. Food competition was more frequent under suboptimal food conditions. Fights for prey were rare within the family, but increased when food was scarce, especially after removal of the adult male. Large prey was defended more frequently than small prey. Under optimal food conditions, the adult male hunted alone and provided the female and the young with food. Under suboptimal conditions, the adult female also hunted for herself and the male fed her a smaller amount. The young got more food per individual than the parents under either condition.