Factors influencing the behavioural development of juvenile New Zealand Falcons (Falco novaeseelandiae)

Abstract

Adult raptors are thought to train their progeny in flight and hunting techniques during the period of dependence after fledging. Parental teaching is poorly understood but its effects may impinge on the success of reintroduction projects where juveniles are released into areas without adults, as is commonly done with raptors. We compared behavioural development over the first 4 weeks after fledging in wild-reared juvenile New Zealand Falcons (Falco novaeseelandiae) with that of juvenile Falcons recently hack-released as part of a conservation initiative. Juveniles with parents spent nearly half as much time perching, spent twice as much time playing, and chased conspecifics five-times more often than juveniles without parents. Juveniles with siblings chased conspecifics 60 times more often, and engaged in twice as much play behaviour compared with juveniles without siblings. We suggest that, provided juvenile New Zealand Falcons are hack-released in groups, reintroduction of this threatened species without adults does not have a major effect on the behavioural development of individuals, although ongoing monitoring to corroborate these results with a larger sample size is recommended.