Synchronous Breeding: Wedge-tailed Shearwaters Puffinus pacificus in Eastern Australia

Abstract

Synchronous summer breeding on islands in the Indian and Pacific Oceans has been reported for Wedge-tailed Shearwaters Puffinus pacificus in both the northern and southern hemispheres. Observations of early hatching in December 1995 at Raine Island, Great Barrier Reef, indicate that the timing of Wedge-tailed Shearwater breeding between colonies may not be as similar as previously thought. This paper shows that in the southern hemisphere there is a disparity in timing of breeding between colonies so southern hemisphere birds do not fit the generally accepted distinction of November–December laying in the southern hemisphereand June–July laying in the northern hemisphere.