Black tern Chlidonias niger

Identification Tips:

Adult alternate:

Adult basic:


First winter/first summer:

Similar species:

Small tern, significantly larger than Least but smaller than Common. Swallow-like flight and feeding habits distinctive. Easily separable from all other regular species by black breast and belly and dark gray upperwings in alternate plumage. More similar in basic and immature plumages but size, irregular dark cap, short bill, and evenly gray upperwing distinctive. The White-winged Tern, accidental in United States, is similar but has whitish upperwings, white rump and tail and black axillaries in alternate plumage. In basic and immature plumages it is very difficult to separate but has black ear spot more separated from crown, whiter rump and tail, shorter bill and lacks shoulder bar.

Length and wingspan from: Robbins, C.S., Bruun, B., Zim, H.S., (1966). Birds of North America. New York: Western Publishing Company, Inc.