American Oystercatcher. Photograph by Lauren Miller-Donnelly.

Introduction

The American Oystercatcher (Haematopus palliatus palliatus) is a regular summer presence on a number of beaches, marshes, and islands along the coast where it nests and forages. It is a charmingly clownish shorebird with bright plumage and a relatively large size atypical of most shorebirds. Its large, emphatically orange bill is a trademark of the species. Often seen in pairs or small groups, it has a loud, heralding call and exaggerated courtship behaviors. When disturbed during incubation, it readily concedes the nest site and vanishes to a distant location to quietly wait out the threat.

American Oystercatchers are long-lived, migratory shorebirds. The Atlantic Coast subspecies breeds from Maine to Florida and winters from New Jersey south to Florida (Working Group et al. 2020). American Oystercatcher is one of only a few shorebird species that nest in temperate latitudes in the eastern United States and are thus, as ground nesters, vulnerable to human disturbance and predators along the heavily developed Atlantic coastline. The state population has been recovering over the past five decades and is currently stable, although not numerous. The opportunity to spot oystercatchers and observe their antics is a special summertime treat.

Information about American Oystercatchers in Massachusetts is available due to the dedicated and concerted efforts of many shorebird conservationists who monitor and protect nesting sites and provide data annually to MassWildlife’s Natural Heritage & Endangered Species Program (see below). The purpose of this paper is to summarize information on the status, ecology, and conservation of American Oystercatchers in the state.

Figure 1. Abundance of nesting American Oystercatcher in Massachusetts, 1969-2020 (bars) and percentage of population nesting in Boston Harbor (●; MADFW 2016-2020; 2012-2020 data are preliminary).