Aleutian Tern
Onychoprion aleuticus

Conservation status | Uncommon and local, colonies vulnerable to disturbance. No obvious trends in population. |
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Family | Gulls and Terns |
Habitat | Northern coasts (summer); open ocean (winter). During most of year apparently at sea, moving south to tropics in winter, although details poorly known. In breeding season along northern coastlines, foraging mostly offshore, nesting on open islands, sandbars, or beaches with dense low ground cover. |
Photo Gallery
Feeding Behavior
Forages mostly by flying or hovering low over water, dipping down to take items from surface; apparently seldom plunge-dives into water.
Eggs
1-2, sometimes 3. Buff to olive, heavily marked with dark brown. Incubation is probably by both sexes, about 22-23 days. Young: Both parents probably bring food for young. Age at first flight about 25-31 days. Young may remain around colony one or two weeks after fledging; age at independence unknown.
Young
Both parents probably bring food for young. Age at first flight about 25-31 days. Young may remain around colony one or two weeks after fledging; age at independence unknown.
Diet
Includes crustaceans, fish, insects. Diet in summer includes many euphausiid shrimp and other crustaceans, small fish, and insects. Winter diet essentially unknown.
Nesting
Usually nests in small colonies, often associated with Arctic Terns. Unlike most terns, parents do little or nothing to defend nest against predators or intruders, simply departing at approach of danger. May benefit by nesting with Arctic Terns, which are more aggressive in defense of colony. Nest site is close to water on low sandspit, island, or beach, among grasses or other vegetation. Nest is inconspicuous, a shallow depression in moss, matted grass, low vegetation.
Illustration © David Allen Sibley.
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Text © Kenn Kaufman, adapted from
Lives of North American Birds
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Migration
Winter range still poorly known, was completely unknown until late 1980s; most apparently winter at sea near the Philippines or Indonesia. Arrives on Alaska breeding grounds in May, departs mostly in August. One seriously lost individual once was found in Britain.

- All Seasons - Common
- All Seasons - Uncommon
- Breeding - Common
- Breeding - Uncommon
- Winter - Common
- Winter - Uncommon
- Migration - Common
- Migration - Uncommon
See a fully interactive migration map for over 450 bird species on the Bird Migration Explorer.
Learn moreSongs and Calls
A musical whee-hee-hee; chirping notes like those of House Sparrow.Learn more about this sound collection.