Vegetation qualities and whitehead stock size

Productivity and group size of communally breeding birds is often considered in terms of the numbers of non-reproductives available to help the breeders. An alternative viewpoint is that group size is largely a consequences of habitat quality. In other words, groups in quality or more diverse habitat can raise and support more young and hence are largest. This study attempts to correlate various measures of habitat with the size of groups of whiteheads on Little Barrier Island. Aspects considered include altitude, canopy height, structural and species diversity as well as indicator species.