By far the largest tern in the region, this species has a black cap in breedsing plumage and a streaked cap in non-breeding plumage, and a red or orange-red bill, usually black-tipped. The underwing tip is black. Royal Tern has a smaller, more orange bill and a more deeply forked tail.
Juvenile has brown fringes to the wing coverts, more grey in the tail, and a paler base and more extensive black tip to the bill.
Islands, bays, estuaries, lagoons, inshore waters and large rivers.
A harsh, grating 'kraaak'.