The Black-bellied Tern (Sterna acuticauda) is a tern found near large rivers in South Asia. They have a black belly in the summer and a deep forked tail. They can sometimes resemble Whiskered Terns but the deeper fork and the black on the lower belly distinguish it from the shallow fork and black closer to the breast on the Whiskered Tern. Considering that mtDNA 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.