Tuesday, March 24, 2009

At the coast... Black Oystercatcher

Black OystercatcherBlack Oystercatcher, Seal Rock, Oregon on 25 March 2007 by Greg Gillson.


These crow-sized shorebirds are rarely found away from rocky shores. Here, they expertly use their long, knife-like bills to pry limpets, mussels, and other marine mollusks from the rocks where they are quickly gobbled up. Paul A. Johnsgard (The Plovers, Sandpipers, and Snipes of the World, 1981) says, "The birds immobilize open mussels (Mytilus) by a stab through the posterior adductor muscles and spread them apart by inserting the closed bill and forcing the valves open. Closed mussels are struck with the bill until a hole is made and the muscles are cut."

Black Oystercatchers are easily identified by their blackish-brown plumage, thick pink legs, long orange-red bill, and orange eye. They have loud piercing calls, easily heard above the roaring surf.

The range of these birds is from the Aleutian Islands south to mid Baja California. They retract a bit from the Aleutians in winter down to southern Alaska, but are residents in most of their range, including the Pacific Northwest coast.

The next time you are at the coast, look for these striking birds at low tide on mussel beds or on basalt headlands, cobble beaches, and jetties.