Caspian Tern

Caspian Tern, adult breeding plumage

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Caspian Tern, adult non-breeding plumage

Caspian Tern juvenile

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1. Description
2. Sound
3. Conservation Status
4. Other Names
5. Cool Facts
6. Full detailed species account

As large as a big gull, the Caspian Tern is the largest tern in the world. Its large coral red bill makes it one of the most easily identified terns throughout its worldwide range.

Description

• Large, gull-like tern.
• Black cap.
• Body white.
• Bill large, thick, and brilliant red with dark tip.

• Size: 47-54 cm (19-21 in)
• Wingspan: 120-135 cm (47-53 in)
• Weight: 530-782 g (18.71-27.6 ounces)

Sex Differences

Sexes look alike.

Sound

Call a raspy "kowk." Juvenile begging call a high pitched whistling; heard frequently during migration and in winter.

Conservation Status

Numbers increasing across North America: using man-made dredge spoil islands and dikes for breeding. Declining in Europe. It is listed as rare or vulnerable in some areas because of the scattered nature of breeding colonies. Beach nesting areas vulnerable to disturbance and predation.

Other Names

Sterne Caspienne (French)
Charrán caspia, Pagaza Piquirroja (Spanish)

Cool Facts

• The oldest known wild Caspian Tern lived to be more than 26 years old. Average life span of Great Lakes Caspian Terns is estimated to be 12 years.

• The Caspian Tern aggressively defends its breeding colony. It will pursue, attack, and chase potential predatory birds, and can cause bloody wounds on the heads of people who invade the colony. The entire colony will take flight, however, when a Bald Eagle flies overhead, exposing the chicks to predation from gulls.

• The largest breeding colony in North America is off the coast of Oregon. Increasing numbers of terns at this site have caused problems with young salmon releases, some of them endangered species. Efforts are being made to move the colony to other areas, away from the fish stocking programs.

• Young Caspian Terns appear to have a difficult time learning to catch fish efficiently. They stay with their parents for long periods of time, and are fed by them even on the wintering grounds. Many young terns do not return to the nesting grounds for several years, remaining instead on the wintering areas.

Sources used to construct this page:

Cuthbert, F. J., and L. R. Wires. 1999. Caspian Tern (Sterna caspia). In The Birds of North America, No. 403 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.