Listing Status
- Federal Status: Not Listed
- FL Status: State-designated Threatened
- FNAI Ranks: G5/S2 (Globally: Demonstrably Secure/State: Imperiled)
- IUCN Status: LC (Least Concern)
Appearance:
The American oystercatcher is a shorebird species that is easily identified by its long, bright reddish-orange bill, yellow eyes, and distinct red eye ring. These features are a contrast to the deep black-colored head, brown and black backside, and white belly. The wings are characterized by a white “V” shape, which can be seen as they are in flight. This large shorebird can reach 18 inches (45.7 centimeters) in length and a wingspan of 32 inches (81.3 centimeters) (National Audubon Society, n.d.).
Since it is one of the largest and heaviest of our shorebirds, the oystercatcher is unmistakable. It is striking in appearance: dark-brown, black, and white, with a bright red bill. When in flight, a diagonal white stripe in each wing forms a V-pattern.
Behavior
The American oystercatcher is one of a few bird species that feed primarily on mollusks, although they will also eat jellyfish, worms, and insects. Because of their preference for mollusks, oystercatchers inhabit coastal areas that support intertidal shellfish. Oystercatcher bills act as strong shucking tools, used to loosen the adductor muscle (the muscle that keeps the shell closed) in the mollusks they eat. Once the muscle is pried loose, the shell is easily opened.
In Florida, American oystercatchers nest in shallow scrapes in the sand or shell, often on open or sparsely vegetated beaches or spoil islands (islands developed from dredged up material). Oystercatchers have also been known to nest on gravel rooftops like another shorebird species, the least tern. Nesting begins in March and can extend through August. Adult males and females take turns incubating the eggs, which generally hatch between 24 and 27 days. Chicks are mobile and leave the nest within hours after hatching, though they remain dependent on adults for food for at least two months. Young become flight capable around 35 days.
Habitat
The American oystercatcher inhabits beaches, sandbars, spoil islands, shell rakes, salt marsh, and oyster reefs. Oystercatchers can be found from the coasts of the northeastern U.S. down to Florida’s Gulf Coast (Nol and Humphrey 1994). Florida is home to both a resident breeding population and a large wintering population of American oystercatchers. Oystercatchers can also be found on the Caribbean coast of Central America. (Nol and Humphrey 1994).
Threats
Many factors threaten the Florida population of American oystercatchers. Coastal development and shoreline armoring have resulted in widespread habitat loss, leaving few suitable breeding sites. Where breeding occurs, nests are vulnerable to disturbance by beachgoers, boaters, pets, predators, and severe weather events. When breeding adults are disturbed, they will fly from their nest, leaving eggs and chicks vulnerable to the elements and waiting predators. American oystercatchers are largely dependent on marine mollusks, which are particularly sensitive to changes in water quality. Oil spills and pollutants can affect distribution and abundance of mollusks, which subsequently affects prey availability for oystercatchers. Global climate change is an impending threat to American oystercatchers as the rise of sea level may further reduce coastal habitat.
Conservation and Management
American oystercatchers are protected by the U.S. Migratory Bird Treaty Act and as a State-designated Threatened by Florida’s Endangered and Threatened Species Rule.
If take of American oystercatchers is unavoidable during otherwise lawful activities, the Florida Fish and Wildlife Conservation Commission may issue an Incidental Take Permit, which must provide a scientific or conservation benefit to the species. Such activities include, but are not limited to, beach construction or development, significant habitat modification, special events with loud noise, or activities occurring on a rooftop during the breeding season For more information on permitting options for Imperiled Beach-nesting Birds, visit the FWC's IBNB Homepage.
In Florida, nests are often protected using symbolic fencing – temporary postings that provide a buffer against disturbance. Documented nests are monitored regularly during the breeding season to determine productivity and assess management techniques. The Florida Shorebird Alliance, a statewide partnership for the conservation of shorebirds, coordinates posting, monitoring, and bird stewardship programs locally.
IBNB Species Conservation Measures and Permitting Guidelines
IBNB Biological Status Review (BSR)
Supplemental Information for the BSR
Species Action Plan
References
Nol, E. and R.C. Humphrey. 1994. American Oystercatcher (Haematopus palliatus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved March 2, 2011 from the Birds of North America Online.