Buller’s shearwater  (Puffinus bulleri)

Buller’s shearwater was previously caught in drift-nets in the north Pacific, with an estimated 4,000 birds killed annually, and may still be at risk from set-nets (6) (8). Longline fishing, trawling operations, and hand-and-reel lines may also pose a threat, although little documented evidence of this exists (6) (8). Furthermore, this bird’s very limited breeding range renders it extremely vulnerable to the effects of accidentally introduced predators, disease, storms and other catastrophes (6) (8). Indeed, the dense colonies nesting on the Poor Knights Islands were once devastated by introduced pigs. Thankfully, after the eradication of the pigs the shearwaters recovered spectacularly and now have a healthy, growing population, but the potential risk to a bird with such a small breeding range nevertheless remains (4).

There was a massive increase in the population after the eradication of feral pigs from Aorangi in 1936, with recolonising populations probably coming from the nearby predator-free island, Tawhiti Rahi (6). The large population is thought to be continuing to grow on the Poor Knights Islands, a protected, now predator-free nature reserve, and if it succeeds in expanding its range, this species may be downlisted to Near Threatened on the IUCN Red List (6) (7).