Photo: Arthur Morris/Vireo

Caspian Tern

Hydroprogne caspia

The largest of the terns, larger than many gulls. Cosmopolitan, nesting on five continents. In North America, it is common along both coasts and locally inland, mainly around large bodies of water. Noted for its long adolescence, with the young dependent on their parents for many months; even in late winter, many an adult Caspian is trailed by a begging youngster from the previous nesting season.
Conservation status Overall population probably stable, perhaps increasing slightly; range has expanded recently to include southern Alaska.
Family Gulls and Terns
Habitat Large lakes, coastal waters, beaches, bays. Found on both fresh and salt water, favoring protected waters such as bays, lagoons, rivers, lakes, not usually foraging over open sea. Inland, more likely on large lakes than on small ponds. Nests on open ground on islands, coasts.
The largest of the terns, larger than many gulls. Cosmopolitan, nesting on five continents. In North America, it is common along both coasts and locally inland, mainly around large bodies of water. Noted for its long adolescence, with the young dependent on their parents for many months; even in late winter, many an adult Caspian is trailed by a begging youngster from the previous nesting season.
Photo Gallery
  • adult, breeding
  • juvenile
  • adult, nonbreeding
  • adult, breeding
Feeding Behavior

When foraging flies high over water, hovers, then plunges to catch fish below surface. Less often flies low, dips down to catch prey at water's surface. May steal food from other birds.


Eggs

1-3, rarely 4 or 5. Pale buff, spotted with brown or black. Incubation is by both parents (female may do more), 20-22 days. Young: May leave nest a few days after hatching, move to nearby shore. If colony is undisturbed, young may remain at nest until ready to fly. Both parents bring food for young. Age at first flight about 30-35 days; young may remain with parents as long as 8 months.


Young

May leave nest a few days after hatching, move to nearby shore. If colony is undisturbed, young may remain at nest until ready to fly. Both parents bring food for young. Age at first flight about 30-35 days; young may remain with parents as long as 8 months.

Diet

Mostly fish. Often concentrates on a few abundant fish species in a given locale (for example, shiner perch on California coast, alewife on Great Lakes). Also eats insects, sometimes eggs or young of other birds.


Nesting

First breeds at age of 3 years. Nests in colonies, sometimes in isolated pairs. Male may fly low over colony carrying fish; female follows. On ground, courtship feeding (male feeds female). Nest site is on bare ground, among driftwood or debris, perhaps sometimes on floating mats of dead vegetation. Nest (built by both sexes) is shallow depression, sometimes with rim or lining of debris.

Illustration © David Allen Sibley.
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Text © Kenn Kaufman, adapted from
Lives of North American Birds

Migration

Inland breeders move to coast and southward for winter. Some winter south to West Indies, northern South America.

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Migration

Inland breeders move to coast and southward for winter. Some winter south to West Indies, northern South America.

  • All Seasons - Common
  • All Seasons - Uncommon
  • Breeding - Common
  • Breeding - Uncommon
  • Winter - Common
  • Winter - Uncommon
  • Migration - Common
  • Migration - Uncommon
Songs and Calls
Low harsh kraa. Also a shorter kow.
Audio © Lang Elliott, Bob McGuire, Kevin Colver, Martyn Stewart and others.
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How climate change could affect this bird's range

In the broadest and most detailed study of its kind, Audubon scientists have used hundreds of thousands of citizen-science observations and sophisticated climate models to predict how birds in the U.S. and Canada will react to climate change.

Learn more

Read more: climate.audubon.org
Gulls and Terns Gull-like Birds

Caspian Tern

The darker the color, the more favorable the climate conditions are for survival. The outlined areas represent approximate current range for each season.

More on reading these maps.

Each map is a visual guide to where a particular bird species may find the climate conditions it needs to survive in the future. We call this the bird’s “climatic range.”

The colors indicate the season in which the bird may find suitable conditions— blue for winter, yellow for summer (breeding), and green for where they overlap (indicating their presence year-round).

The darker the shaded area, the more likely it is the bird species will find suitable climate conditions to survive there.

The outline of the approximate current range for each season remains fixed in each frame, allowing you to compare how the range will expand, contract, or shift in the future.

The first frame of the animation shows where the bird can find a suitable climate today (based on data from 2000). The next three frames predict where this bird’s suitable climate may shift in the future—one frame each for 2020, 2050, and 2080.

You can play or pause the animation with the orange button in the lower left, or select an individual frame to study by clicking on its year.

The darker the color, the more favorable the climate conditions are for survival. The outlined areas represent approximate current range for each season. More on reading these maps.
Winter
Summer

Winter Range
Summer Range
Both Seasons
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