American Oystercatcher

(Haematopus palliatus) (AMOY)

Photographic Identification Guide

American Oystercatchers (Haematopus palliatus) (AMOY), are large, showy and noisy shorebirds of the Atlantic and Gulf of Mexico seashores. They are restricted to marine environments because they feed primarily on saltwater mollusks and crustaceans. Their numbers in New England, though greatly reduced due to hunting in the 19th century, have increased dramatically over the past few decades; they are now among the most conspicuous breeding birds along southern New England shores.

There are four other recognized subspecies of American Oystercatcher scattered along both coasts of the Americas. Nearly all are short-distance migrants and, as a consequence, do not often turn up in unlikely places, unlike more long-distance migratory shorebirds.

In this guide, we cover the features, in order of importance, to look for on these birds. When discussing plumages, we use the terms winter, spring, and summer to refer to northern hemisphere seasons. Because some of these birds spend different parts of the year in the northern and southern hemispheres, the correct technical terms for the plumage stages—basic and alternate—help avoid the confusion of northern temperate seasonal terminology.

visual gallery

species account

2

Fig. 1. American Oystercatcher. Winter (basic) plumage. Note yellow tip to bill. Fort Desoto Park, Pinellas, FL. 11 December 2022.
1

Fig. 2. American Oystercatcher. Winter (basic) plumage. South Padre Island, Cameron, TX. 14 February 2014.
1

Fig. 3. American Oystercatchers. Adult (alternate plumage) pair. Boston Harbor, MA. 25 May 2022.
1

Fig. 4. American Oystercatcher in flight. Summer (alternate) plumage. Snake Island, Winthrop, MA. 1982.
0

Fig. 5. American Oystercatchers. Piping display or territorial dispute. Winthrop Five Sisters, Winthrop, MA. 30 May 2017.
0

Fig. 6. American Oystercatchers courtship display. Boston Harbor, MA. 11 June 2024.
1

Fig. 7. American Oystercatchers. Adult with newly hatched chick. Nickerson Beach, Nassau, NY. 19 June 2024.
0

Fig. 8. American Oystercatcher. Half-grown chick. Nickerson Beach, Nassau, NY. 27 July 2024.
1

Fig. 9. American Oystercatcher. Juvenile plumage closely resembles adult. Monomoy National Wildlife Refuge, Chatham, MA. 30 May 2017.
0

Fig 10. American Oystercatchers. Adult and juvenile. Note shorter bill of juvenile. Monomoy National Wildlife Refuge, Chatham, MA. 10 August 2022.
0

Fig. 11. American Oystercatchers. Adult and juvenile. Note dark eye and dusky-tipped bill of juvenile. Winthrop Beach, Winthrop, MA. 18 September 2016.

The photos in this species account are arranged in this order:

Basic: very dark gray (nearly black) head and neck, brown back, white underparts.

American Oystercatcher molts to winter (basic) plumage in September and usually completes the molt by the end of the calendar year; see Fig. 1, Fig. 2.

Alternate: first spring and summer after hatch year or adult breeding plumage, mid-February to October.

See Fig. 3. In adults, there is little difference between basic and alternate plumage.

Chick: newly hatched baby is downy and short billed.

See Fig. 7.

Juvenile: young fledged birds, May to November.

The juvenile is similar to the adult, but for a short while, it has the characteristic scalloped back pattern of many juvenile shorebirds; see Fig. 9.

Size and weight

Females are slightly larger and have longer bills.

Body length:

16–17.5 in. (40.6–44.4 cm)

Wingspan:

29.25–32.5 in. (74.3–82.6 cm)

Bill length:

3–4 in. (75–100 mm)

Weight:

14.1–24.7 oz. (400–700 g)

Calls

American Oystercatcher social life is generally noisy; it gets particularly rowdy during courtship and its attendant group displays. A characteristic display, which starts between a mated pair, consists of each bird whistling loudly while gesticulating with head and neck. This behavior, called piping, may lead to other oystercatchers in the vicinity joining in, calling and gesticulating. At times, a group of three to six or more birds begins to fly about, back and forth over the nesting territory, all birds calling loudly. This display maybe repeated three or more times during a typical day.

Examples of piping display may be found on YouTube channel. Examples:

Plumage and other characteristics

With its chunky body, nearly black head and neck, brown back, white underparts, pink legs, bright red bill and conspicuous yellow eye with a red orbital ring, an adult American Oystercatcher is unmistakable in any season; see Fig. 1, Fig. 2.

The long red bill has a bright yellow tip, particularly conspicuous during breeding season, April to July; see Fig. 3.

In flight, the broad brownish wings are bisected by wide white stripes. The tail is white at the base, blackish at the outer end; see Fig. 4, Fig. 5.

Newly hatched chicks are fully covered in brown and beige down. They run about shortly after emerging from eggs; see Fig. 7.

As the chick grows, the down is replaced by a soft layer of feathers with gray-brown centers and brown and rusty subterminal margins; see Fig. 8. Throughout this stage of growth, unlike most shorebirds, oystercatcher parents feed their young and teach them how to forage for their specialized food; opening tightly shut shellfish requires skills which are passed on from parents to youngsters.

After a month or more, young oystercatchers molt into a plumage that closely resembles the adults. The main difference is that juveniles have upper wing coverts with the pale scalloped margins characteristic of many juvenile shorebird species. Other features are a somewhat shorter bill with a red base and a dusky tip, dark eyes and dusky legs; see Fig. 9, Fig. 10.

After an American Oystercatcher molts into its first winter (basic) plumage, visually it appears roughly the same throughout the rest of its life. There is little difference between winter (basic) and spring or summer (alternate) plumage. However, first-year and sometimes even second-year birds may be slightly paler on the head and back than adult (2- to 3-year- old) birds.

↹

Breeding range, migration, wintering range, habitat

American Oystercatcher in North America is a coastal nesting species, rarely found farther than 10 miles from the Atlantic Ocean or the Gulf of Mexico.

During the breeding season, its center of abundance ranges from New Jersey to South Carolina. The New England and New York nesting populations are healthy and growing, particularly in the south of the region. Nesting birds can be found, rarely, as far north as Nova Scotia.

Nesting locales for these birds vary from sandy beaches to coastal gravel bars and rocky outcrops.

Birds in Virginia and the Carolinas— the central part of the range—are considered sedentary; migration, if any, amounts to short-distance flights to point slightly south of their nesting areas.

In winter, New England birds migrate longer distances, hopscotching over the mid-Atlantic birds and often ending up in Florida or the Caribbean. Another center of abundance for wintering birds is the southern Texas coast and the northeast coast of Mexico.

The oystercatcher’s primary food is marine invertebrates: crustaceans, bivalves, mollusks and sea worms. Its specialized, flattened bill allows it to feed on clams and mussels, which it opens by cutting through the adductor muscle that keeps the two halves of the shell shut tight.