The American Oystercatcher is a large coastal shorebird about the size of a crow that is easily identified. It is hard to miss because of its long oversized reddish orange beak, black head and back that contrast with a white belly. It shows a broad wing stripe in flight and has a penetrating whistling call that announces its presence.
Oystercatchers may use one of two techniques to feed on bivalves like the Ribbed Mussel found at Salter Grove. Either the stout bill is jabbed into a partly opened shell to pull out the soft contents, or it is used to hammer the shell until it breaks. They also feed on other intertidal invertebrates such as jellyfish, sand crabs, and worm.
Readily observed along the Marsh Trail from marker M6 and southward, the nest site on Rock Island is near the northernmost edge of the species's breeding range. Although a single pair was observed to hatch three chicks at Salter Grove in 2019, it is not known if they managed to fledge successfully. Dozens of Common Terns occupied the same nesting area soon after nestlings appeared and no more than two oystercatchers were observed thereafter. On March 31 of 2020, three adults were seen on the nesting rock.