Considering that sequence analysis supports moving the similar black-fronted tern ("Sterna" albostriata) into Chlidonias, this species might also be better placed in that genus, but no research has yet been conducted.

[3][4] Outside the breeding season, the belly is whitish, the tail is reduced in length and the bill has a dark tip.

[1] The rationale behind this is that the riverine habitats in which it breeds are under threat in much of southeastern Asia and, although it has an extensive range, it is believed to be extinct in southern China, Nepal, Thailand, Laos, Cambodia and Vietnam.

Only in Pakistan, India and Bangladesh are there larger populations, and even in these countries, this bird is thought to be seriously declining, and there may be fewer than one thousand mature individuals in existence.

[1] The threats it faces include the degradation of the islands and sandspits on which it breeds, the collection of eggs for food, predation of eggs and chicks by dogs, cats and crows, flooding of nesting sites by the construction of river dams, competition for fish by local fishermen, entanglement in nets, disturbance, extraction of water, sand and gravel dredging and pollution.