Its long yellow bill and black cap stand out. It lives mainly along rivers and lakes in South America.
It has a long yellow bill and black crown, with white, black, and gray patterning on the wings.
Large-billed Terns breed on sandy river beaches in South America. A study of rainfall seasons and breeding locations combined literature, citizen-science records, fieldwork, and museum specimens. Seasonal rainfall was associated with the timing of breeding and the distribution of these terns along the continent's river systems.
The terns breed on sandbars and river beaches during the dry season, when water levels fall. As the rainy season begins and rivers rise, they leave breeding areas and disperse in small groups or singly. Birds moving outside the breeding season tend to follow South America's larger rivers and occur in a different pattern from the flocks seen at breeding colonies.
An extinction-risk assessment has not been added yet.
Large-billed Terns in South America breed on sandbars and sandy riverbanks exposed during the dry season. After rains raise river levels, they disperse in small groups or singly along major rivers.