Cross-Fostering New Zealand's Black Stilt

Abstract

To increase fledging success and recruitment of young birds into the breeding population of endangered black stilts (Himantopus novaezelandiae) in New Zealand from 1981 to 1987, we protected nest-sites from predators and manipulated egg production through multiple clutching and cross-fostering to pied stilts (H. himantopus). Pairs producing multiple clutches fledged more young (P < 0.01) than did unmanipulated pairs and more young fostered to black pairs were resighted than those fostered to hybrid (black × pied, pied × hybrid, and hybrid × hybrid) pairs, juveniles cross-fostered to pied or hybrid stilt pairs migrated with foster parents but did not return to breed. More emphasis has been placed on increasing the success of chicks reared under black stilt parents since 1988