By Peter Vankevich
If there were a betting popularity contest for the birds of Ocracoke, Las Vegas might place the American Oystercatcher as a 4 to 1 most likely to win top of the list.
This handsome shorebird, often seen on the beach, got its name from naturalist Mark Catesby in 1731 when he observed it using its long orange bill to pry open oysters and other bivalves for food.
More than 40 species of shorebirds have been seen on the Outer Banks but only a few, including the oystercatcher, nest in North Carolina.
Many shorebirds are difficult to identify since they closely resemble each other. Not so with the distinctive oystercatcher.
Large for a shorebird, they are 18 inches in height with a 32-inch wingspan. In addition to a long, bright orange bill, they have pinkish legs and a distinctive black and white plumage. The head and breast are black; the back dark brown and the underparts are white. In flight the large white stripe on its wings is clearly visible. The eyes are another striking feature, which are bright yellow and with an orange orbital ring. Males and females are visually indistinguishable.
Not great architects, oystercatcher nests, barely noticeable, are shallow scrapes on sandy areas like the beach. The average clutch is two to four eggs that
are buffy gray and speckled with brown spots. One may encounter one of their eggshells on the beach as the parents remove them from nest after hatching.
In North Carolina nesting begins in early April. If the eggs are lost to predation or overwash, they will lay a new clutch. The average incubation period is slightly less than a month. Both the male and female share family responsibilities, including incubation and later assisting with feeding that lasts for several months.
In Ocracoke in 2021, 14 American Oystercatcher nests produced nine fledglings.
The chicks are precocial, meaning they are mobile within 24 hours of hatching, but it takes up to 60 days for their beaks to become strong enough to pry open bivalves. The young birds may remain with their parents for up to six months. American oystercatchers can live 10 years or longer.
Oystercatchers forage by tactically probing the substrate with their long bills, then using them as a shovel to loosen the sand and push the prey upward.
When feeding on bivalve mollusks, including clams, limpets and mussels, they employ two techniques. One described as “stabbing,” where they quickly insert the knife-like bill into the open valves and sever the adductor muscle that holds the two valves together to get to the soft parts.
The other foraging method is described as “hammering.” The oystercatcher orients the prey item with its bill and begins hammering. Once they have broken through the shell, the soft parts are then consumed.
Oystercatchers will also prey on other marine invertebrates, such as sea urchins, starfish, mole crabs and marine worms.
Population estimates for the Atlantic Coast from Texas to New England along the Gulf Coast and the eastern Atlantic seaboard are more than 11,000 individuals.
Their numbers have increased and expanded in their northern range of eastern North America with nesting in small numbers as far north as Nova Scotia.
Historically, they may have had an even wider distribution as John James Audubon reported seeing one in Labrador in 1835.
Oystercatchers observed on Ocracoke frequently have color-coded bands. If you record the code or even a partial part of it, you can send this information to the website of the American Oystercatcher Working Group. More than 75,000 reports have been sent there relating to the more than 6,000 banded birds. You can also send your report to the Bird Banding Laboratory.
When to see: Year-round, most common in spring and summer, Far fewer in late fall and winter. Two were observed on the Ocracoke Island Christmas Bird Count on Dec. 31. On nearby Portsmouth Island, a large wintering flock can often be seen along the north flats and from the village haulover dock looking out to Casey Island.
Listen: They can be noisy during breeding season. The Macaulay Library at the Cornell Lab of Ornithology has a variety of oystercatcher recordings. Click here.
Where: On the beach, especially South Point, the rocks at Springer’s Point and around the NCCAT building, exposed sand bars and shallow low tide waters of the Pamlico Sound.
The American Oystercatcher (Haematopus palliatus palliatus) is one of the most studied birds in North Carolina covering migration, winter habitats, distribution, abundance and existing and potential threats.
They are listed as a “Species of Special Concern” by the NC Wildlife Resources Commission (NCWRC) and are listed by nearly every Atlantic coast state as threatened, endangered or special concern. In the U.S. Shorebird Conservation Plan, it is listed as a “Species of High Concern.”
A common story of many bird species, during the 18th and 19th centuries, American oystercatchers were hunted for food and their plumage. By 1918, when the Migratory Bird Treaty Act was implemented, they were close to extirpation along the Atlantic Coast. They have rebounded but face a multitude of threats.
There is concern that with rising sea levels, increased overwash will cause nesting failures. Human disturbance, mammalian and avian predators abound in their preferred nesting areas, along with ghost crabs which have been known to eat newly hatched chicks.