A North American tern of wetlands and coasts whose head pattern changes between breeding and nonbreeding plumage.
Adults in breeding plumage have a gray back, black cap, and orange bill with a black tip. In nonbreeding plumage they are paler overall, with a thick dark eye patch.
In the breeding season, it nests in colonies in fresh, brackish, or salt marshes and plunge-dives for small fish. Many inland breeders move toward the coast after their young fledge.
An extinction-risk assessment has not been added yet.