General
Caspian Tern: Largest tern, stocky with pale gray upperparts and white underparts. Cap is black and may appear weakly crested; large bill is coral-red with a black tip. Undersides of primaries are gray. Tail is white, relatively short, and slightly forked; legs are black. Sexes are similar. Winter adult has dark streaked cap and white eye rings. Juvenile resembles winter adult but has gray chevrons on white back, mainly white crown, dark gray legs, tail and primaries are dark gray; has a red-orange bill with a black tip.
Range and Habitat
Caspian Tern: Breeds in scattered colonies from central Canada, Great Lakes, and Newfoundland south to the Gulf coast and Baja California. Spends winters north to California and North Carolina. Also breeds in Eurasia, Africa, and Australia. Preferred habitats include sandy or pebbly shores of lakes and large rivers and along coasts.
Breeding and Nesting
Caspian Tern: Pairs begin to form nest scrapes soon after they arrive at the breeding grounds. They breed in late May and early June. One to five brown marked pink buff eggs are laid in a shallow depression in sand, often lined with shell fragments and grass. Incubation ranges from 20 to 28 days and is carried out by both parents. The young begin to fly at 37 days after hatching.
Foraging and Feeding
Caspian Tern: These terns primarily eat fish such as mullet and menhaden. They occasionally consume crayfish and insects. They plunge dive or catch fish at the surface while flying above. They also steal food from other birds. Typically they fish along coasts, shorelines, inland lakes, rivers, lagoons, estuaries and sloughs; less commonly they forage on open sea.
Vocalization
Caspian Tern: Call is harsh deep "kaark" or "ka-arr."
Similar Species
Caspian Tern: Royal Tern has orange bill and deeply forked tail.