American Oystercatcher

American Oystercatcher

American pied oystercatcher

Kingdom
Phylum
Class
Genus
SPECIES
Haematopus palliatus
Population size
43-110 thou
Life Span
10-17 yrs
WEIGHT
400-700 g
LENGTH
42-52 cm
WINGSPAN
81 cm

The American oystercatcher is a large shorebird that is marked by its black and white body and a long, thick orange beak. Its head and breast are black in color and the back, wings, and tail are greyish-black. The underparts are white, as are feathers on the inner part of the wing which become visible during flight. The irises of this bird are yellow and the eyes have orange orbital rings. The legs are long and pink in color.

Distribution

American oystercatchers are found on the Atlantic coast of North America from New England to northern Florida, where they are also found on the Gulf Coast, and south to Brazil, Uruguay, and Argentina. They are found also in the Pacific coast of California, Mexico, Central America, Peru, and Chile. During the breeding season, these birds are found along the Atlantic and Gulf Coasts and from Massachusetts south to Argentina and Chile. In winter, they are found along the coast from central New Jersey to the Gulf of Mexico. American oystercatchers breed in coastal habitats including sand or shell beaches, dunes, salt marshes, marsh islands, mudflats, and dredge spoil islands made of sand or gravel. During migration and winter, they are common in mud or salt flats that are exposed by the tide. They are also found on shellfish beaches at this time.

American Oystercatcher habitat map

Climate zones

Habits and Lifestyle

American oystercatchers are social birds and prefer to roost on flocks. They are active during the day spending time foraging, preening, resting, and sunbathing. These birds prefer to move by walking or running rather than flying. They are able to swim and dive but will do so only to escape from aerial predators. Oystercatchers are closely tied to coastal habitats where they nest and hunt their prey. In general, they use their large heavy bills to catch shellfish. As they walk across a shellfish bed, they look for a mollusk with a partially opened shell. When they find one, they jab their bill into the shell and sever the muscle that causes the shell to clamp shut. This can be dangerous, however, as they are sometimes drowned when they don't completely severe this muscle, and the shell clamps down on their bill. A strong, tightly rooted mollusk can hold the bird in place until the tide comes in. They also feed by carrying loose shellfish out of the water and hammering at the shell or by probing the sand for soft-shell or razor clams. American oystercatchers are very noisy birds. They communicate with the help of 'wheep' or 'kleep' shrill and also make a loud 'pic pic pics'.

Group name
Seasonal behavior

Diet and Nutrition

American oystercatchers are carnivores (piscivores, vermivores). They feed almost exclusively on shellfish but will also eat marine worms, mussels, clams, limpets, sea urchins, starfish, and crabs.

Mating Habits

MATING BEHAVIOR
REPRODUCTION SEASON
April-July
INCUBATION PERIOD
25-27 days
INDEPENDENT AGE
95 days
BABY NAME
chick
BABY CARRYING
2-4 eggs

American oystercatchers are monogamous and often may for life. They breed between April and July. When courting, the birds will walk together and make a single piping note. This progresses to leaning towards each other, extending and lowering the neck, and running alongside each other while calling. The pair may then burst into flight and fly in a tight formation around their territory. These birds nest on beaches on coastal islands. Their nests are shallow depressions scraped into the sand; the pair will make 5 or more of these scrapes, then choose one to line with shells and/or pebbles. The female lays 2-4 eggs per nest. The eggs are gray in color and speckled with dark brown. Both parents incubate the eggs for about 25-27 days. When born, the chicks are covered in tan down and can run within 2 hours of hatching. They are considered semi-precocial young as they can leave the nest soon after hatching but still rely on their parents for food. Chicks will fledge at about 35 days old. After fledging, they still rely on their parents for food as it takes up to 60 days for the beak to become strong enough to pry open mollusks. During this time, care of the chicks is evenly divided by the parents. Young American oystercatchers will start breeding when they're 3 to 4 years old.

Population

Population threats

Historically, American oystercatchers were hunted to near extinction in the 19th century for plumage and eggs. They have recovered significantly since 1918, however, at present in some states, these birds are listed as a species of concern because of low and declining populations. They are vulnerable to loss of habitat due to development on the coasts and sea level rise. American oystercatchers are also threatened by pollution, disease, and invasive species which can impact food availability.

Population number

According to the What Bird resource the total population size of the American oystercatcher is approximately 110,000 individuals. According to Wikipedia resource, the current population of this species is 43,000 individuals. There are estimated to be 1,500 breeding pairs along the Atlantic and Gulf Coasts of the US. Currently, American oystercatchers are classified as Least Concern (LC) on the IUCN Red List and their numbers today are stable.

Fun Facts for Kids

  • Originally the American oystercatcher was called the "sea pie". It was renamed in 1731 when naturalist Mark Catesby observed this bird eating oysters.
  • When American oystercatcher chicks escape predators, they dive and propel themselves underwater using wings; after a short distance they surface and swim away. When chicks become a little older they are able to dive several meters deep and can swim underwater up to 10 meters. On the surface, they are able to swim 400 meters and even more!
  • American oystercatchers are territorial and both males and females defend the territory, however, males are usually more aggressive. When disturbed these birds start to bob their head.
  • When American oystercatchers defend their nests or perform courtship or territorial displays, they use slow “butterfly flight”.
  • When American oystercatchers sleep they hide their bill under scapulars.

References

1. American Oystercatcher on Wikipedia - https://en.wikipedia.org/wiki/American_oystercatcher
2. American Oystercatcher on The IUCN Red List site - https://www.iucnredlist.org/species/22693644/93416407

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