Monitoring Hutton’s shearwater 1986-1989

The distribution of Hutton’s Shearwater (Puffinus huttoni) in the Kaikoura ranges is restricted to the upper Kowhai River and Shearwater Stream catchments. Survey quadrats were established and colony boundaries mapped as baseline data for monitoring. The breeding population was estimated to be at most 134 400 pairs, less an unknown number of non-breeding pairs and unmated birds. Productivity in used burrows in the Kowhai River and Shearwater Stream catchments was estimated at 31% and 16% respectively. Numbers have declined since the 1880s. The species fits the IUCN category of ‘vulnerable’.