Mendocino Coast Audubon Society logo Mendocino Coast Audubon Society

Black Oystercatchers
The Black Oystercatcher Conservation Project: A Collaborative Multi-Agency Effort

One of four year-round shorebirds, the Black Oystercatcher Haematopus bachmani, spends its entire life cycle along the rocky intertidal zone of the Pacific Ocean where it feeds on mollusks. It can be seen alone, in pairs, or in large groups. Most of all, its piercing call can be heard over the heaviest of surf. From May to September, monogamous pairs defend nesting territory above the high tide line along the headlands and sea stacks.

The oystercatcher is considered vulnerable to decline due to its small global population size (10,000-12,000), low reproductive success and complete dependence on rocky intertidal shorelines. Oystercatchers are associated with healthy, productive marine intertidal habitat, which prescribes them as an indicator species of intertidal marine health. The long term goal of the Black Oystercatcher Conservation Project is to apply additional knowledge to current conservation efforts that will preclude the need for an Environmental Species Act listing. In 2009, the U.S. Fish and Wildlife Service (USFWS) listed the oystercatcher as a "species of focal concern."

In response to these considerations and lack of historical information, Audubon California undertook the first targeted survey in 2011 measuring distribution, abundance, and reproductive success in a subset of suitable intertidal habitats in California.

The Mendocino Coast Audubon Society organized a group of volunteers to help with the population survey along the Mendocino County coastline. Once thought to number around 1000 in California, final results accepted by the Journal of Marine Ornithology in February of 2014 suggest upwards of 5,000 oystercatchers.

The nest success study began on a small scale, covering only a few areas of established high density. The goal is to establish initial data on habitat status and fledgling success trends for at least five years. Over the past three years, studies have been conducted in fifteen California coastal counties.

The Mendocino Coast Audubon Society currently receives a Chapter Grant from Audubon California to coordinate and advise volunteers and agency collaborators on guidelines, protocol, and data collection. Weekly surveys, May to September, are performed at select sites of high species density. A public outreach campaign was initiated by our chapter in 2013 through a Challenge Grant from the Bureau of Land Management's California Coastal National Monument Program. Visit

This project is an ongoing collaborative effort between California Audubon, Mendocino Coast Audubon Society, California State Parks, Bureau of Land Management and Resources Legacy Fund Foundation's (RLFF) Oceans, Coasts, and Fisheries Program.

To volunteer as a citizen scientist for this project, contact Terra Fuller at (707) 937-3689 or Amelia Schall at (707) 937-2645.

2007 Black Oystercatcher Conservation Action Plan for W. US (PDF)
2011 First Population Assessment CA 1.2014 accepted (PDF)
2012 Black Oystercatcher Conservation Report (PDF)
2013 Black Oystercatcher Conservation Report (PDF)
2014 Black Oystercatcher Conservation Report (PDF)
2015 Black Oystercatcher Conservation Report (PDF)
2016 Black Oystercatcher Conservation Report (PDF)
2017 Black Oystercatcher Conservation Report (PDF)
2018 Black Oystercatcher Conservation Report (PDF)

Black Oystercatcher links:
Audubon California's site for the science and conservation of Black Oystercatchers.
Black Oystercatcher Breeding Survey 2007 on the Oregon Coast(PDF)
Black Oystercatcher Conservation Plan (PDF)

Funded by:
2011 MCAS and volunteer citizen science effort
2012 Collaborative Chapter Grant from Audubon California
2013 Audubon California and Bureau of Land Management's CCNM Program
2014 Audubon California Chapter Grant

Black Oystercatcher photo by Bill Delameter
Survey photo by Joleen Ossello
Volunteer photo by Ron LeValley