Monitoring California’s Black Oystercatchers

Jun 25, 2016

Audubon California naturalist Anna Weinstein spots a Black Oystercatcher on a rocky outcropping off Bodega Head.
Credit Bruce Robinson, KRCB

  Black Oystercatchers are distinctive, but not numerous. So these hardy shorebirds are being monitored by naturalists and citizen scientists to see how they are affected by sea level rise and other environmental factors.

Because their food supply lies in the rocky shoreline along the coast, Oystercatchers are rarely seen very far inland. But in their narrow habitat, says Audubon California naturalist Anna Weinstein, they are easy to identify.

The Black Oystercatcher's nesting site, and even the eggs in it, blend naturally into their rocky habitat.

  Oystercatchers are notoriously territorial, and will aggressively defend their area against interlopers as well as predators. Yet there are places off the Sea Ranch bluffs where birdwatcher Diane Hitchwa reports that some nesting pairs that are close together have apparently developed an understanding about who hunts where.