Black Oystercatcher

Bird of the Month: Black Oystercatcher

By Hugh Jennings

PC: Mick Thompson (Black Oystercatcher)

PC: Mick Thompson (Black Oystercatcher)

Scientific Name: Haematopus bachman

Length 17.5 in

AOU Band code BLOY

The Black Oystercatcher (BLOY) is 17-1/2” long.  Its genus Haematopus (he-MAT-oh-pus) is from the Greek haimatopous for blood foot, brightly colored feet.  The species name, bachmani, was given in 1838 by John James Audubon for his friend the Rev. John Bachman.  Adults are large all-black or all-brownish birds with a bright red bill, pink legs and feet.  Immatures are browner and have a dusky bill, orange, at the base.

They are resident along the Pacific coast where the ocean breaks against rocky shorelines and the birds stalk about on the rocks and nearby flats.  If disturbed, they take flight with loud, ringing whistles like, wheep-wheep, which are easily heard above the sound of the waves.  They are present in all seasons.

The BLOY eats mostly mussels, limpets and other shellfish and forages mostly at low tide, resting at high tide.  When feeding on mussel beds, they usually remove the mussel from its shell and leave the shell in place.  Oystercatchers may mate for life and usually nest on islands.  Pairs typically defend a breeding territory that includes an elevated area for nesting, well above high tide.  The nest is built by both parents and is a slight scrape with 2-3 eggs are laid, sometimes one, which are pale buff to olive, spotted and scrawled with brown and black.  Incubation is by both sexes and takes 24-29 days.  Downy young chicks follow their parents to the feeding areas and are fed by them there.  The young can fly at about 5 weeks and begin to catch some of their own food.  They are mostly permanent residents with no regular migration.