American Oystercatcher

The American Oystercatcher is a very new addition to New Hampshire’s list of breeding birds. Although it nests to the north and south of us, it wasn’t until 2022 that a pair settled on the New Hampshire portion of the Isles of Shoals and successfully raised two chicks. As the population out on the islands continues to grow, it’s likely that additional pairs will set up shop in the future. This colonization of the Granite State is at least partially the result of concerted conservation efforts elsewhere in the range. Like many other coastal species, oystercatchers require undisturbed beaches for their nests, and are also vulnerable to predation and sea level rise. In some parts of the mid-Atlantic, oystercatchers are shifting to nest on man-made islands made of dredge material, where they are safer from some of these threats.

The large red bill of the American Oystercatcher is an exceptional tool, combining features of scissors, hammer, shovel, and pliers. The birds feed primarily on bivalves such as oysters and clams and seek out those with their shells partially open. When a suitable prey item is found, the oystercatcher rapidly slides its bill into the gap and severs the muscle holding the two halves of the shell together. It then grabs and swallows the soft animal inside without needing to worry about the shell closing. Oystercatchers will also use their bills to pound holes in shells near the muscle to gain access or dig into mud to get buried clams. They will also prey on burrowing marine worms in the manner of other long-billed shorebirds.