A global assessment of the conservation status of the Black Oystercatcher Haematopus bachmani David F. Tessle r1, James A. Johnso n2, Brad A. Andres 3, Sue Thoma s4 & Richard B. Lancto t2 1Alaska Department of Fish and Game, Division of Wildlife Conservation, Wildlife Diversity Program, 333 Raspberry Road, Anchorage, Alaska 99518 USA.
[email protected] 2United States Fish and Wildlife Service, Division of Migratory Bird Management, 1011 East Tudor Road, MS 201, Anchorage, Alaska 99503 USA 3United States Fish and Wildlife Service, Division of Migratory Bird Management, 755 Parfet Street, Suite 235, Lakewood, Colorado 80215 USA 4United States Fish and Wildlife Service, Washington Maritime National Wildlife Refuge Complex, 715 Holgerson Road, Sequim, Washington 98382 USA Tessler, D.F., J.A. Johnson, B.A. Andres, S. Thomas, & R.B. Lanctot. 2014. A global assessment of the conser - vation status of the Black Oystercatcher Haematopus bachmani . International Wader Studies 20: 83 –96. The Black Oystercatcher Haematopus bachmani , a monotypic species, is one of the less studied members of the genus. The global population of roughly 10,000 individuals is scattered unevenly along the North American Pacific Ocean coast from the Aleutian Islands to Baja California, with the vast majority (about 80%) in Alaska and British Columbia. Favouring rocky shorelines in areas of high tidal variation, they forage exclusively on intertidal macroinvertebrates (e.g. limpets and mussels). Because they are completely dependent on marine shorelines, the Black Oystercatcher is considered a sensitive indicator of the health of the rocky intertidal community. Breeding oystercatchers are highly territorial, and nesting densities are generally low; however, during the winter months they tend to aggregate in groups of tens to hundreds.