Caspian Tern

Hydroprogne caspia

  • Version: 2.0 — Published January 1, 1999
  • Francesca J. Cuthbert and Linda R. Wires

Free Introduction Article Access

The Introduction Article is just the first of 11 articles in each species account that provide life history information for the species. The remaining articles provide detailed information regarding distribution, migration, habitat, diet, sounds, behavior, breeding, current population status and conservation. Each species account also includes a multimedia section that displays the latest photos, audio selections and videos from Macaulay Library’s extensive galleries. Written and continually updated by acknowledged experts on each species, Birds of North America accounts include a comprehensive bibliography of published research on the species.

A subscription is needed to access the remaining account articles and multimedia content.

Subscribe Now

Already a subscriber? Sign In
Figure 1. Distribution of the Caspian Tern in North and Middle America.

And the western Caribbean. This species winters locally within the area denoted as 'migration', and also breeds in Europe, Asia, Africa, and the Australian region.

Adult Caspian Tern; NY State, August

Note beginning of white forehead -- early stages of Definitive Prebasic molt. Cayuga Lake, NY; 14 Aug 2005.; photographer Brian L. Sullivan

Breeding adult and juvenile Caspian Tern; NY State, August

9 Aug 2005; Myer's Point, Cayuga Lake, NY.  Young continue to be fed by parents for several months after fledging. ; photographer Gerrit Vyn

Editor’s Note (November 2017): Maps, rich media, and text have been updated to reflect a taxonomic change for this species. This account is being revised and may contain content from an earlier version of the account.

The largest tern, the Caspian Tern is distinguished by its massive coral red bill, hoarse vocalizations, and similarities to large Larus gulls in flight. Bent (Bent 1921) described it as “king of all the terns . . . the dominant ruling spirit in the colonies . . . the largest, strongest and fiercest of the terns.” Its broad, expansive wings allow it to soar and wheel dramatically like a gull, and its slow wing beats power a graceful flight that is strong and swift. Its loud raucous call is heard frequently in breeding colonies, especially when nesting birds are approached by intruders.

With the exception of Antarctica, the Caspian Tern occurs on all continents, breeding and/or wintering along coastlines and inland along rivers, lakes, and marshes. In North America, it breeds at scattered localities along the Pacific, Atlantic, and Gulf Coasts, and inland in the western interior, Prairie Provinces of Canada, and along the Great Lakes. It generally nests in colonies. Flat rocky islands, beaches, and sandy shores, sparsely vegetated and littered with driftwood, are typical breeding habitat for this species. Its nests range from mere scrapes in sand or gravel to clam shell or vegetation lined depressions with elaborately built-up rims that contain mollusk shells or crayfish appendages. Changing water levels often lower nesting success, as does competition with gulls and harassment by predators and humans. Birds desert colonies readily if disturbed early in the breeding season.

Caspian Terns from North America winter along the southern portions of the Atlantic and Pacific Coasts and the Gulf Coast, as far south as Colombia and Venezuela.

This species lives almost entirely on fish, capturing them in shallow surface waters near breeding and wintering sites. When fishing, flies with bill pointing downward; spotting a fish, it hovers, flexes its wings and plunge-dives, usually submerging completely.

Populations of this tern have increased in most parts of its North American range, owing to protection of the species and its traditional nesting sites, and to human alterations in habitat. In Europe and Africa, however, it has declined and is now extinct or rare in parts of its former range (Cramp 1985a).

In North America, the Caspian Tern has been studied mainly during the breeding season in freshwater and marine habitats. Information on phenology, nesting, parental behavior, mate and site fidelity, habitat, and diet is available from studies conducted in the Great Lakes and on the Pacific and Gulf Coasts (Baltz et al. 1979, Quinn 1980, Clapp et al. 1983c, Cuthbert 1985a, Cuthbert 1988, Ewins et al. 1994b). Band recovery data have illuminated movement patterns and overwintering sites for Great Lakes and Pacific Coast populations (Ludwig 1942, Ludwig 1965b, Gill and Mewaldt 1979, Gill and Mewaldt 1983).

Recommended Citation

Cuthbert, F. J. and L. R. Wires (1999). Caspian Tern (Hydroprogne caspia), version 2.0. In The Birds of North America (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA.