FOOD SUPPLEMENTATION INDUCES PROVISIONING OF YOUNG IN COOPERATIVELY BREEDING WHITE-WINGED CHOUGHS

Cooperatively breeding White-winged Choughs have an extremely long per iod of post fledgling care, they will provision young for up to eight months. During winter, however, provisioning ceases despite evidence t hat young continue to have difficulty finding food themselves. A provi sioning experiment was designed to determine whether food availability played a role in the termination of care. Groups of White-winged Chou ghs were observed before, during, and after food was supplied in both small and large amounts. The supply of large amounts of food switched on provisioning behaviour in both breeders and helpers, and begging be haviour in juveniles. Helping behaviour is therefore influenced by the costs of supplying food.