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Species Database

Haematopus bachmani - Black Oystercatcher

Black Oystercatcher image

Geographic range:

Aleutian Islands, Alaska to Baja California, Mexico

Key features:

Black body with a long, bright red bill.

Habitat(s):

exposed rocky shore, exposed sandy beaches, protected rocky shore, protected sandy beaches
 

Primary common name:

Black Oystercatcher

General grouping:

Seabirds and shorebirds

ITIS code:

176475
 

Geographic Range

Range Description:

Haematopus bachmani can be found along the Pacific coast from the Aleutian Islands, Alaska to Baja California, Mexico.

Habitats

exposed rocky shore, exposed sandy beaches, protected rocky shore, protected sandy beaches

Habitat notes:

Haematopus bachmani occupies rocky shorelines and islands. It less commonly occupies sandy beaches.

Abundance

Relative abundance:

Haematopus bachmani is common in its coastal range throughout all seasons.

Species Description

General description:

Haematopus bachmani is a large, conspicuous and noisy bird of the Oystercatcher family, family Haemotopodidae, in the Class Aves. They are nonmigratory rocky shorebirds with distinctive specially designed bills that can reach into shellfish and pry them open.

Distinctive features:

The adult Haematopus bachmani is all black with a long, red, chisel-shaped bill. The eyes are yellow with a red eye ring. The legs are sturdy and pinkish. The immature Haematopus bachmani is browner in color and the bill is orange with a black or dusky tip. It should be noted that the plumage of Haematopus bachmani can vary according to location. From Alaska to Oregon, Haematopus bachmani is entirely black, but southward from there, it shows increasing amounts of white feathers and browner abdomens.

A similar species, the American Oystercatcher, Haematopus palliatus, can be distinguished by its brown back, white belly, white rump and large white stripes in its wings.

Size:

Haematopus bachmani can grow to be about 47 cm and weigh about 700 g.

Natural History

General natural history:

Haematopus bachmani is usually seen in pairs or in small to medium-sized flocks, but may aggregate into larger flocks in sheltered areas. The voice of Haematopus bachmani is a piercing kleep that can be heard any time of year above the noise of the pounding surf.

Predator(s):

Mammals, such as rats, and birds of prey, such as ravens, prey on the eggs of Haematopus bachmani.

Prey:

Haematopus bachmani feeds on clinging mollusks such as the Rough Limpet, Lottia digitalis, and shellfish such as mussels. It feeds less commonly on sand invertebrates, such as worms and crabs.

Feeding behavior

Carnivore

Feeding behavior notes:

Haematopus bachmani uses its laterally flattened bill to reach into mollusks, pry their shells open and disable them with a quick jab to their abductor muscle. They can also use their bill to pry limpets from rocks and to probe in the sand for worms and crabs. Once their prey has been dislodged from rock, they use their chisel shaped bill is used to scrape and pull the contents out of shells. They forage mostly during low tide and in the wave zone where mussels that are splashed by waves open more readily. In the winter they may forage in small flocks.

September - May

Migration:

There is no regular migration for Haematopus bachmani since it generally remains in its nesting areas. However some movement is seen in the spring and fall, also some may move farther south in the winter.

May - August

Reproduction:

Haematopus bachmani breeds on non-forested islands with shell or gravel beaches above the high intertidal zone. Birds will defend territory that encompasses both nesting and feeding areas. Apparently, males and females form long term bonds and will return to the same territory year after year. Both partners will help build a nest that consists of a small scrape in the ground that is sparsely lined with pebbles or shell pieces. The female lays one to four eggs and both the male and female incubate the egg for about three and a half to four weeks. Unlike many other shorebirds, the parents bring food to the young for a prolonged period of time. At the age of about five weeks, the young can fly and begin to forage on their own, yet their parents still provide food.
Click on an image below to view a larger version in the SIMoN Photo Library. You will also be able to view important information on each photo such as photographer, date, caption and more.
Alden, P., F. Heath, R. Keen, A. Leventer, and W. Zomlefer. 2002. National Audubon Society Field Guide to California. A.A. Knopf, New York, NY.
Dunn, J.L. 1999. Birds of North America. National Geographic, Washington, D.C. 464 p.
Langstroth, L. and L. Langstroth. 2000. A Living Bay: The Underwater World of Monterey Bay. University of California Press, Berkeley and Los Angeles, CA. 287 p.
WWW
Cornell Lab of Ornithology
All About Birds
http://www.allaboutbirds.org/guide/search
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WWW
Seattle Audubon Society.
http://www.seattleaudubon.org/birdweb/
Accessed 01/30/2009 for Pelagic Cormorant
Accessed 02/28/2009 for Marbled Godwit
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Accessed 03/15/2009 for Whimbrel
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