Topic: Black Billed Gull
Topic type:
The Black Billed Gull holds the 2008 National Threat Category of Nationally Endangered. They have been seen nesting at Mangawhai Wildlife Refuge, adjacent to Te Arai, and use Te Arai Beach, Stream and lakes for fishing and the Te Arai stream mouth as a high tide roost.The Black billed gull usually nests in the South Island on small islands in braided and shingle rivers.
Black Billed Gull (Larus bulleri)
Adapted for sustained, soaring flight, the black-billed gull has a compact body with long wings and a fan-shaped tail to help control movement in strong winds. With typical colouration for a gull, the black-billed gull can be distinguished by its black bill, legs, feet and wing tips.
Range and Habitat
Endemic to / found only in New Zealand. Resides on the small islands of braided rivers, the margins of lakes, in parks, and on wet lawns, sheep pastures and ploughed fields. It is found both in coastal regions and further inland, typically moving closer to either the coast or to towns during the winter, after breeding inland.
Biology
During the breeding season the black-billed gull returns to the same site it visits every year and pairs begin to build deep depressions of twigs and grass during October. The female lays between one and three eggs on lake edges or in braided rivers, and these are incubated by both the male and female for about 22 days continuously. After hatching, the chicks are fed by their parents until they fledge around 26 days later. The family stays at the breeding site until fledging unless disturbed when they may abandon the nest as soon as the majority of their eggs have hatched, moving on to coastal habitats for the winter. The young are able to breed after two years, but more normally will not pair up until three or four years of age.
Threats Habitat loss, predation, planting out of streams with exotics.
