Midway, Necker, Nihoa, Ogasawara. Where exactly does Bryan’s Shearwater breed in the North Pacific?

Peter Pyle (The Institute for Bird Populations, Point Reyes Station, California, USA) and colleagues write in the open-access journal Marine Ornithology on the little-known Bryan’s Shearwater Puffinus bryani.

The paper’s summary follows:

“Little is known about the conservation requirements of Bryan’s Shearwater Puffinus bryani, first described in 2011 based on a specimen collected in February 1963 near an area containing concrete rubble at Midway Atoll.  Here we document a second Bryan’s Shearwater observed on Midway during the winters of 1990/91 and 1991/92.  It was vocalizing from a 0.5–0.7 m crevice within an accumulation of artificial concrete and coral rubble.  Recent winter specimens of Bryan’s Shearwaters from the Bonin (Ogasawara) Islands, Japan, were also collected in areas with rocky crevices, possibly burrows they co-utilize with summer-breeding Bulwer’s Petrels Bulweria bulwerii.  This habitat is not found naturally on low-lying atolls in the Northwestern Hawaiian Islands; however, it does occur on Nihoa and Necker Islands, where Bulwer’s Petrels breed abundantly.  Digitized video and vocalization recordings from 1991 on Midway, detailed here and available at http://www.birdpop.net/index.php/en/brys, are currently being used to locate breeding Bryan’s Shearwaters in the Bonin Islands.  Similar monitoring should be considered for Nihoa and Necker Islands.  None of five at-sea records of small shearwaters in the central and eastern North Pacific Ocean can be confirmed as Bryan’s Shearwater; thus, nothing is currently know of its life history or requirements at-sea.”

The Midway Bryan's Shearwater, photograph by Reginald David

Click here to access three previous ACAP Latest News postings on Bryan's Shearwater.

Reference:

Pyle, P., David, R., Eilerts, B.D., Amerson, A.B., Borker, A. & Mckown, M. 2014.  Second record of Bryan’s Shearwater Puffinus bryani from Midway Atoll, with notes on habitat selection, vocalizations and at-sea distribution.  Marine Ornithology 42: 5-8.

John Cooper, ACAP Information Officer, 18 May 2014