In the 2012 President's Budget Request, the National Biological Information Infrastructure (NBII) is terminated. As a result, all resources, databases, tools, and applications within this web site will be removed on January 15, 2012. For more information, please refer to the NBII Program Termination page.
The Black Oystercatcher (Haematopus bachmani) has been identified as a focal species due to its low overall population numbers (8,900-11,000 globally), lack of information about important breeding, migratory and wintering sites, unknown population trends, and a growing number of threats to oystercatchers themselves and the habitats on which they rely. Major threats include coastal development and increased human disturbance in the southern part of its range (Washington to Baja California), and nest overwash by boat wakes, human disturbance, and shoreline contamination (oil spills) in the northern part of its range (Alaska and British Columbia). Other factors contributing to low population numbers include low reproductive success, possible adult mortality due to predation by introduced predators, and global climate change with all its resultant effects on habitat and resources.
Date: February 2008
Source: Tessler, D.F., J.A. Johnson, B.A. Andres, S. Thomas, and R.B. Lanctot. 2007. Black Oystercatcher (Haematopus bachmani) Conservation Action Plan. International Black Oystercatcher Working Group, Alaska Department of Fish and Game, Anchorage, Alaska, U.S. Fish and Wildlife Service, Anchorage, Alaska, and Manomet Center for Conservation Sciences, Manomet, Massachusetts. 115 pp.
Species Profile from NatureServe
Black Oystercatcher Haematopus bachmani
Description:A relatively large, all-black shorebird, with a heavy, bright-red bill typical of oystercatchers. Bright yellow iris with orange-red orbital ring in adults; sturdy, pale pink legs. Females have longer, narrower bills and heavier bodies (Andres and Falxa 1995).
Life History:Eggs laid late May-early July (generally early to mid-June) in Alaska, mid-May to late June (generally mid-June) in Washington/Oregon, early May-late June (generally late May) in southern California (L'Hyver and Miller 1991). Clutch size 1-4 (usually 2-3). Incubation 26-27 days, by both sexes. Nestlings precocial but dependent on parental feeding for several weeks (both sexes feed young). Chicks begin to fly at 35+ days. Long-term mate fidelity. See Terres (1980), Groves (1984), Purdy and Miller (1988).
Winter flocks seldom range more than 30 miles from nesting sites (Terres 1980), except in northern populations (Andres and Falxa 1995). Obligate users of intertidal zone year-round. Period from hatching until time of first flight is critical life-history stage (Groves 1984).
Habitat:
Estuarine Habitat(s): Tidal flat/shore
Terrestrial Habitat(s): Bare rock/talus/scree
Breeding: Habitat is exclusively associated with the high tide margin of the inter-tidal zone, and includes mixed sand and gravel beaches, cobble and gravel beaches, exposed rocky headlands, rocky islets, and tidewater glacial moraines. The southern limit of their range coincides with a change of rocky shores to sandy beaches (Jehl 1985). Breeding territories are usually in close proximity to dense mussel beds. Avoids brushy and forested habitats. Breeding density is generally greatest on non-forested islands and islets. Nest is a shallow circular depression on the ground (e.g., scrape on beach of broken shell) or on a rock (Groves 1984). The retreat of glaciers, which expose gravel moraines, and uplift from earthquakes can create new oystercatcher nesting habitat (Lentfer and Maier 1995, Gill et al. 2004).
Non-breeding: In winter, flocks concentrate on protected, ice-free tidal flats with dense mussel beds (Hartwick and Blaylock 1979).
Distribution:
United States: AK, CA, OR, WA
Canada: BC
Status:
NatureServe Status: Global Status: G5
Global Status Last Reviewed: 25Nov1996
Global Status Last Changed: 25Nov1996
Rounded Global Status: G5 - Secure
Other Statuses: IUCN Conservation Status - Least concern (LC)
