This medium-sized tern has a white head and body with a gray back. It catches fish and lives around marshes and shallow waters in South America.
Its head stays white in every plumage, and its back is gray. The patch behind the eye is black in breeding plumage and gray in non-breeding plumage; the bill also changes color by season.
It dives into water to catch fish. When breeding, it builds a floating nest and anchors it.
An extinction-risk assessment has not been added yet.