Taranui/Caspian Tern Sterna caspia
Native. Threatened-nationally vulnerable.
This is by far the largest species of tern to be seen at the Estuary, and with a wingspan of a metre makes it similar in size to the Black-backed Gull.
It is a large, stocky tern weighing as much as 780gms with a black cap that touches the beak when in breeding plumage, with a slight crest. The legs and feet are black, while the heavy beak is conspicuously red. Upperparts are grey and the underparts white. In flight the lower side of some of the primary wing feathers look black. In non-breeding plumage the black cap may be flecked with white.
When feeding the Caspian Tern flies along over the water, 5 to 10 m up, looking down into the water to search for fish. On spotting one, it plunges down in a dive and enters the water briefly. Food is consumed while in flight.