The genus name is from Ancient Greek onux, "claw" or "nail", and prion, "saw".

[3] Three of the four species are tropical, and one has a sub-polar breeding range.

The Aleutian tern breeds around Alaska and Siberia but winters in the tropics around South East Asia.

Manutara is the Rapa Nui language name for spectacled and sooty terns.

Both arrive at Easter Island and hatch their eggs on the island called Motu Nui, an event that was used for an annual rite called Tangata manu.