Black Tern

Chlidonias niger

HOW TO IDENTIFY:

* Length: 9 inches Wingspan: 35 inches
* Sexes similar
* Slow swallow-like flight
* Swoops down and picks prey off surface off water
* Small tern with relatively short, black bill
* Very short, dark legs
* Short, notched tail
* Smoothly rounded head without crest

Adult alternate:

* Dark legs
* Black head, neck, breast, and belly
* White undertail coverts
* Dark gray back; and upperwings with no apparent contrast
* Gray rump and tail
* Pale underwing coverts

Adult basic:

* White face, foreneck, breast, and belly
* Irregular black cap connected to dark ear spot
* Entirely gray back and upperwing (paler than in alternate plumage)
* Dark gray shoulder bar

Juvenile:

* White face, foreneck, breast, and belly
* Irregular black cap connected to dark ear spot
* Brownish back and upperwing
* Dark gray shoulder bar

First winter/first summer:

* Like adult basic but often with blackish mottling in 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.