The black-fronted tern is seen from the southern tip of the North Island, and along much of the eastern South Island from Marlborough to Southland and to Stewart Island. There is an outlying population along the Buller and upper Motueka Rivers in southern Nelson. The breeding range is restricted to the South Island. While most terns are seabirds, the black-fronted tern lives and breeds inland along riverbanks and can forage out to 10 km at sea in the non-breeding season in autumn and winter (distribution map). Numbers are decreasing across its range due to introduced mammalian pests and the Australian magpie (Cracticus tibicen).
The black-fronted tern (Chlidonias albostriatus) also known as the riverbed tern or tarapiroe (Māori), is a medium to small tern endemic (unique) to New Zealand, measuring 28-29cm and weighing 95grams. It is unique amongst terns in that it is the only one to breed exclusively inland. They nest in colonies on open shingle or small islands in the river.
Predominantly grey plumage over most of the body with black cap extending down over the eyes to the bright red-orange beak. During the non-breeding season the black cap recedes from the bill and becomes flecked with white. The underparts and rump are white, and there is a thin white streak running along the cheeks underneath the cap. The legs are orange.
Their eggs and chicks are well-camouflaged, barely distinguishable from shingle.