Grey-Backed Tern

Sterne à dos gris
Oreore

They Grey-backed Tern is a black bird with a white underside. It has a black lines on either side of the head that extend from the back of the head, over eye, to the beak like a mask. The mask creates a white eyebrow that allows the Grey-backed Tern to be distinguished from the Sooty Tern. This bird is also slightly smaller than the Sooty tern with a wingspan of 73 to 76 cm. They hunt small fish and cephalopods that are near the surface and, unlike the Sooty Tern, may dive for their food. The Grey-backed Tern is a pelagic animal (lives over the ocean), but returns to land during the reproductive season of June to November. The birds nest in groups exclusively on the motu Tahuna iti. They lay a single egg that is pale pink with brown spots directly into a depression in the sand. The male and female take turns incubating the egg which is typically 4.3 by 3.3 cm. In 2014 there were 16 couples estimated in Tetiaroa.