Providing evidence to improve practice

Individual study: Cross fostering Newell's shearwaters Puffinus newelli into wedge-tailed shearwater nests P. pacificus is successful on the island of Kaua'I, Hawaii, USA

Published source details

Byrd G.V., Sincock J.L., Telfer T.C., Moriarty D.I. & Brady B.G. (1984) A cross-fostering experiment with Newell's race of Manx shearwater. The Journal of Wildlife Management, 48, 163-168


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Foster eggs or chicks of petrels and shearwaters with wild non-conspecifics (cross-fostering) Bird Conservation

A replicated partially controlled study at two sites on Kaua’i, Hawaii, USA, in 1978-80 (Byrd et al. 1984) found that Newell’s shearwater Puffinus newelli (formerly P. puffinus newelli) eggs transferred to wedge-tailed shearwater P. pacificus had high hatching and fledging rates, with an average of 74% of 90 fostered eggs producing a fledgling. This is similar to the highest recorded rates for Manx shearwaters P. puffinus and slightly higher than those of wedge-tailed shearwaters. The main cause of mortality was egg predation by introduced common mynas Acridotheres tristis, with only one chick being evicted by foster parents. Fostered chicks were slightly heavier and larger than Newell’s shearwaters raised by their natural parents. Data was not available on the return rates or breeding success of fostered chicks.