Post-fledging dependence period and development of flight and hunting behaviour in the Red Kite Milvus milvus

Abstract

he post fledging dependence period of 37 Red Kites was studied in the Doñ¸ana Biological Reserve (Spain). The juveniles fledged at a mean age of 55.1 days and remained near the nest, depending on their parents for food, for on average a further 25.6 days. Flight behaviour of the fledglings showed both a gradual increase in time spent flying and a transition from flapping to gliding and soaring flights. Hunting behaviour and manipulative play with objects were very rare during 511 hours spent observing juveniles during the post fledging dependence period. It seems that juveniles do not start searching for food until they are independent. On average young kites were captured in baited traps for the first time 31.5 days after fledging. Some juveniles dispersed from the natal area as they became independent but most remained in the natal area for a variable period of up to 42 days before dispersal. Mortality during the postfledging period was 13.5%.