WatchList Species Account for Newell’s Shearwater (Puffinus newelli)

Qualifies for the list as a Red List Species

Photo: Jack Jeffrey

Sometimes treated as one of the eight races of the P. puffinus complex or as a well-marked race of P. auricularis, the Newell’s Shearwater breeds only in a few colonies on the Hawaiian Islands, principally in the mountains of mongoose-free Kauai, where there has recently been a significant decline of some 60% from 1993 to 1999. Overall the species is thought to have declined by 50% in the last 47 years, primarily due to loss of nesting habitat. It breeds in colonies from 160 to 1,200 m in burrows by a densely-matted native fern, on steep slopes; apparently prior to the introduction of predators, its nesting habitat was not restricted by gradient. Only about 20 colonies are known. Some of the colonies are far inland, as much as 14 km on Kauai.

Though little is known about food items taken, squid appears to be an important part of the bird’s diet. An important mortality factor is collisions with power lines on Kauai, which accounts for the deaths of 70 adults and 280 subadults each summer, and 340 fledglings each autumn. Hurricanes devastated the forests of Kauai in 1982 and 1992, and since then, numbers of the bird on Kauai have been declining. Habitat degradation and predation by cats, rats, dogs, pigs and the introduced Barn Owl further threaten the species. During the nonbreeding season, Newell’s Shearwater is highly pelagic, and is found in tropical and subtropical waters overlying depths over 2,000 m, to the east and south of the Hawaiian Archipelago.

The overall population has been estimated at 84,000 individuals, but surveys in colonies will never be adequate to estimate numbers since the terrain in these colonies is too difficult to allow such work to be done. The species is listed as federally threatened under the Endangered Species Act and BirdLife International classifies it as endangered.