Delving

March 8, 2010, 9:12 am • Tags: , ,

icon_32The Black Oystercatcher is a conspicuous black bird found on the shoreline of western North America. It ranges from the Aleutian Islands of Alaska to the coast of the Baja California peninsula. It is a large, noisy bird with a massive long orange or red bill used for smashing or prying open mollusks.

It is restricted in its range, never straying far from shores, in particular favoring rocky shorelines. It has been suggested that this bird is seen mostly on coastal stretches which have some quieter embayments, such as jetty protected areas. It forages in the intertidal zone, feeding on marine invertebrates, particularly mollusks such as mussels, limpets and chitons. It hunts through the intertidal area, searching for food visually, often so close to the water’s edge it has to fly up to avoid crashing surf.

The diet of oystercatchers varies with location. Species occurring inland feed upon earthworms and insect larvae. The diet of coastal oystercatchers is more varied, although dependent upon coast type; on estuaries bivalves, gastropods and polychaet worms are the most important part of the diet, where rocky shore oystercatchers prey upon limpets, mussels, gastropos and chitons. Other prey items include echinoderms, fish, and crabs.

The Black Oystercatcher is a territorial bird during the nesting season, defending a foraging and nesting area in one territory. Some pairs have been recorded staying together for many years. Nests are small bowls or depressions close to the shore in which small pebbles and shell fragments are tossed in with a sideward or backard flick of the bill.