|Conservation status||Has declined in some areas with loss or degradation of marsh habitat. Recreational boating on nesting lakes may have impact as well, since wakes from speedboats often flood nests.|
|Family||Gulls and Terns|
|Habitat||Marshes (fresh or salt), lakes, bays, beaches. During summer is mostly around marshes, either coastal salt marsh or large marshy lakes in the interior. May visit any waters during migration. Winters mostly along coast, especially around estuaries, inlets, coastal lagoons, sheltered bays.|
Forages by flying and hovering over water, plunging to take fish from just below surface. Also may dip down in flight to take items from surface, and will forage in the air, catching insects in flight.
3, sometimes 1-4. Olive to buff, variably marked with brown. Incubation is by both sexes, 23-25 days. Young: Both parents feed young in nest. Development of young and age at first flight not well known.
Both parents feed young in nest. Development of young and age at first flight not well known.
Fish, insects, other small aquatic life. Diet is mostly fish at all seasons, but in summer on marshes may eat many insects. Also eats small crustaceans, frogs.
May breed in loose colonies, with spacing dictated by arrangement of good nesting sites. Sometimes associated with colonies of Yellow-headed Blackbird. Aggressive toward other birds in vicinity of nest. Nest site is in marsh, on top of dense vegetation or mats of floating dead plants, often on top of muskrat house. Sometimes placed on ground near marsh, or on abandoned nest of grebe. Where it nests in same marsh as Black Tern, Forster's tends to choose higher and drier nest sites. Nest (built by both sexes) is platform of reeds and grasses, with deep hollow at center lined with finer material and shells.
Illustration © David Allen Sibley.
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Text © Kenn Kaufman, adapted from
Lives of North American Birds
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Much less migratory than Common Tern, wintering regularly along southern coastlines of United States.
- 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 this species on the Bird Migration Explorer.Learn more
Songs and CallsHarsh nasal beep.
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How Climate Change Will Reshape the Range of the Forster's Tern
Audubon’s scientists have used 140 million bird observations and sophisticated climate models to project how climate change will affect this bird’s range in the future.
Zoom in to see how this species’s current range will shift, expand, and contract under increased global temperatures.
Climate threats facing the Forster's Tern
Choose a temperature scenario below to see which threats will affect this species as warming increases. The same climate change-driven threats that put birds at risk will affect other wildlife and people, too.