The rest of their plumage is white, with pale silvery-grey wings and mantle, apart from the outermost primary feather which has a narrow black outer web.

The tail is white, and deeply forked, extending (like the related roseate and white-fronted terns) beyond the wingtips on perched birds.

[4][5][6] There are two listed subspecies:[5] The Black-naped tern inhabits rocky shores throughout the Western-Pacific and Indian oceans, migrating yearly to islets and islands serving as breeding grounds.

[7] Like most terns, this species hunts by diving; they partially breach the surface of the water and directly capture their prey carrying it horizontally in their beak.

Nests are made past high tide in depressions in sand or rock, sometimes delineated with shells or coral fragments, otherwise with little preparation.

To defend against this, parents camouflage the nest by removing eggshell remnants and defecating several meters away to avoid bright eye-catching material near the chicks.

[8] On one occasion, a colony of Black-naped terns were observed using mobbing, shrill cries, and defecation as defence mechanisms against an encroaching Grey Heron during the breeding season.