Cabot's tern is a species of bird in subfamily Sterninae of the family Laridae, the gulls, terns, and skimmers. It is found in the eastern United States and Middle America, the Caribbean, Trinidad and Tobago, and in every mainland South American country except Bolivia and Paraguay, though rare in Chile. It is also a vagrant in eastern Canada and western Europe.
Region
Western Atlantic and Caribbean Basin
Typical Environment
Breeds along the Atlantic and Gulf coasts of the southeastern United States, through the Caribbean and Middle America, and along much of the Atlantic and Caribbean coasts of South America. Uses sandy barrier islands, shell spits, coral cays, and dredge-spoil islands for nesting. Forages mostly over nearshore waters, estuaries, lagoons, and inlets, rarely venturing far offshore. Frequently roosts on beaches and sandbars and shifts locally with prey availability and storms.
Altitude Range
Sea level to 100 m
Climate Zone
Subtropical
Ease of Keeping
Beginner friendly: 1/5
Cabot's tern was long treated as the American form of the Sandwich tern but is now widely recognized as a separate species. It breeds colonially on low, sandy islands and is highly sensitive to disturbance and predation at nesting sites. Identification hinges on its slender black bill with a yellow tip and the dark wedge in the outer primaries. Some tropical populations can be resident, while northern breeders shift south after nesting.
T. a. acuflavidus in non-breeding plumage, Venice Beach, Florida.
T. a. eurygnathus at Cassino, Rio Grande do Sul, Brazil. Note the largely yellow bill.
Breeding colony of T. a. eurygnathus on an islet off Puerto Deseado, Santa Cruz, southern Argentina
Temperament
social and active
Flight Pattern
strong, buoyant flier
Social Behavior
Highly colonial nester, often in mixed-species groups with other terns and gulls. Nests are shallow scrapes on open sand or shell, with both sexes incubating and feeding the chick. Displays include fish-carrying courtship and aerial chases. Post-breeding, adults and juveniles gather in loose flocks along coasts.
Migratory Pattern
Seasonal migrant
Song Description
Calls are loud, harsh, and grating, often rendered as a sharp kirrick or kerrick given in flight and at colonies. Alarm calls are rapid kek-kek series, with softer contact notes when loafing.
Plumage
Pale gray upperparts and white underparts with a deeply forked tail; black cap in breeding with a slight shaggy crest, receding to a mottled crown and white forehead in nonbreeding plumage.
Diet
Primarily small schooling fish such as anchovies, silversides, and sardines, taken by shallow to mid-height plunge-dives. Also consumes small crustaceans and occasional squid when fish are scarce. Often feeds in loose flocks and may associate with predatory fish or marine mammals that drive prey to the surface. Adjusts foraging to wind and tide conditions to maximize strike success.
Preferred Environment
Nearshore marine waters, tidal estuaries, inlets, and lagoons. Common along surf zones and tidal rips where prey concentrates, and around sandbars and reef edges. Rarely ventures far offshore except during dispersal.
