This species is one of several small white terns that do not attain a definitive alternate plumage until at least their third spring (nearly three years after hatch date). Alternate Adult has gray back and upper wing surface, pale gray underparts, forked tail shorter than folded wings, white face, black cap (extends to base of bill) and nape, long red bill with black tip, and red legs. Second summer (Alternate 1) birds are similar to alternate adults, but have white foreheads and darker outer primaries. First summer birds are similar to basic adult, but darker on the lead edge of the upper wing and secondaries. Birds in "winter" plumage during the summer months can be assumed to be first summer. Note that this age class is rarely seen at breeding areas with most remaining on or nearer wintering grounds. Basic Adult has white underparts, dark black smudge on shoulder, black bill and legs, and a white forehead. Black mask around the eye connects across the nape and hind crown. Juvenile suggests a basic-plumaged adult with golden brown scalloping on back and wing coverts, golden brown on forehead, mostly orange bill, orange legs, and dark shoulder. In all plumages sexes are similar. In flight, note fairly long head and neck extension in front of wings, dark leading edge on primaries, and a broad trailing edge on the underside of the primaries. Similar Arctic Tern, shows less head and neck in front of the wings, and narrower dark trailing edge on the underside of the primaries. When perched, Arctics have a shorter bill, are shorter-legged, and show lighter wingtips.

Length: 31 (cm) Wingspan: 76 (cm)

Voice:

Short, harsh, squeaky calls.

Habitat:

Lakes, islands, marshes, and coastlines.

Behavior:

Breeds in large colonies, sometimes with Arctic Terns where range overlaps. Nest is a scrape or platform of vegetation on ground.

Feeding:

Plunge-dives to catch fish and other small aquatic organisms.