Natural La Jolla: Clever oystercatchers forage along rocky shores

NATURAL LA JOLLA:

The black oystercatcher (Haematopus bachmani) is a conspicuous shorebird that may be found along the west coast from Alaska down to Baja California. It is seen less often in Southern California, because the birds prefer rocky shorelines.

Oystercatchers are entirely black except for their bright red bill, dull pink legs, and a yellow eye ringed with red. The American oystercatcher is a similar species but has different coloring and lives on the east coast of the United States. They forage among rocky tidepools, looking for mussels, limpets, and other shellfish that they pry off the rocks with their strong beak.

These birds nest near their foraging areas and both sexes defend the nest site and the nearby food sources. Pairs form long-term bonds and stay together over multiple nesting seasons. Nests are made on grassy or gravelly areas and two or three eggs are laid. Both parents care for and defend the eggs and then also the chicks once they hatch.

Food is brought to the chicks at first but they are soon able to follow their parents to the rocky areas to forage for themselves. These birds prefer to walk, rather than run or fly, although they will fly up if startled, making a loud call as they go.

In La Jolla, I often see them on the outside of the seawall at Children's Pool, on the rocks that are exposed at low tide.

— Kelly Stewart is a marine biologist with The Ocean Foundation who writes about the flora and fauna of La Jolla. She may be reached by e-mail: naturallajolla@gmail.com

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