Sterna caspia
(Caspian Tern)

Physical Description:
19-23" (48-58 cm). Large, bulky tern with a shallowly forked tail. Black cap with a slight crest; large, spear-shaped, red bill with a dark tip; streaked forehead. Extensive black primaries on underside.

Similar Species- Elegant and Royal Terns

Song:
A hoarse, low kraa-uh, deeper than other terns; also repeated kaks. Immature birds utter a high, whistled whee-you.

Distribution:
Breeds locally (mostly in interior, but on coast in Washington and California) in Washington, eastern Oregon, northern Utah, northwestern Wyoming, Idaho (recent range expansion), and North Dakota, south to southern California, western Nevada and northern Mexico. Also breeds in portions of Canada, and locally on Atlantic and Gulf coasts and U.S. Great Lakes. Winters mainly north to California and North Carolina, and south to Mexico, sometimes to northern South America.

Diet:
Eats mainly fishes, but will also eat eggs and young of other terns and gulls.

Ecology
Least gregarious tern; nests singly, or may form colonies of up to several thousand pairs (in Idaho, average colony size is 11.5 nests). Nests in rocks or on ground (in Idaho, nesting sites are on islands). When not breeding, often rests with flocks of other terns. Dives from air to obtain food at water surface; sometimes feeds from surface like a gull.

Reproduction:
clutch varies from 2-3 eggs. Both parents incubate eggs (20-22 days) and tend young, which leave nest in a few days, and first fly at 4-5 wk.

Conservation:

Element Code:	ABNNM08020
Status:	Protected nongame species
Global Rank:	G5
State Rank:	S1
National Rank:	N4N5B,N4N

Important State References:
Trost, C.H. and A. Gerstell. 1994. Status and distribution of colonial nesting waterbirds in southern Idaho, 1993. Dept. Biol. Sciences, Idaho St. Univ., Pocatello. 74pp.