Caspian Tern (Hydroprogne caspia) — identification, habitat & look-alikes

The Caspian Tern is the world's largest tern, with a heavy red bill that stands out over U.S. lakes and coasts. It dives for fish and may nest on open islands in large colonies.

Appearance

Appearance: This sturdy tern is 18.5–21.3 in (47–54 cm) long. It has a massive red bill, a black cap during the breeding season, and a shallowly forked tail.

Look-alikes

Royal TernThalasseus maximus

The Caspian Tern has a deeper red, heavier bill and a more shallowly forked tail. The Royal Tern (Thalasseus maximus) has a bill that is slimmer and orange.

Why they get mixed upBoth are large terns with warm-colored bills.

Common TernSterna hirundo

The Caspian Tern is much larger, with a thicker bill and a shorter, less deeply forked tail.

Why they get mixed upBoth can show a black cap and a reddish bill.

Where it lives

Typical habitats: Coastal islands
Large lakes
Estuaries
Range: It breeds around the Great Lakes and at scattered coastal and inland sites in the United States. During migration, it also uses rivers and reservoirs.

Behavior

Diet: It mostly eats fish and sometimes catches or large insects.
Activity: It scans the water from the air and plunges down to catch fish.

Life cycle

Nest: Pairs make shallow depressions in sparsely vegetated sand or gravel near water.
Clutch size: 1–3 eggs

Conservation

IUCN Red List: LCLeast ConcernLow risk of extinction

Culture and stories

Culture and stories: The name refers to the Caspian Sea, where early bird researchers knew this species.

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