Family Gulls, Terns, Skimmers (Laridae)

Endangered

Black-billed Gull (Larus bulleri)


Taxonomy

French: Mouette de Buller German: Maorimöwe Spanish: Gaviota maorí
Taxonomy:

Larus bulleri

F. W. Hutton

, 1871,

New Zealand

.

Some recent authors place this species and other “masked gulls” in genus Chroicocephalus (see L. philadelphia, above). A recent molecular study indicated that this species was sister to L. novaehollandiae#R. Rarely hybridizes with L. novaehollandiae (race scopulinus), even where breeding alongside it (L Rotorua). Morphometric analysis links it with L. ridibundus or L. genei. Monotypic.

Distribution:

New Zealand, breeding on South I (mostly on the Mataura, Oreti, Aparima and Waiau rivers) and at a few sites on North I. Winters mainly on S North I and N South I, some straggling to Stewart I and Snares Is.

Descriptive notes

35–38 cm; 190–270 g; wingspan c. 90 cm. Very pale gull, distinguished by mainly white wingtip with narrow black trailing border, and long, slender black bill;... read more

Voice

Quite noisy, especially around breeding colonies. Calls include a short grating scream, “krrreh”,... read more

Habitat

Frequents coasts, rivers, lakes, parks, wet lawns, sheep pastures and ploughed fields. On the South... read more

Food and feeding

Mainly earthworms, insects, small fish and aquatic invertebrates; sometimes refuse. Gregarious forager; flocks follow plough, and feed on... read more

Breeding

Courtship begins in August, along coast; colonies occupied by mid-September; often deserted early in season when food supply poor. Flocks... read more

Movements

After fledging period, adults and young move mainly to coastal habitats, with some movement north;... read more

Status and conservation

ENDANGERED. Previously considered not globally threatened but many South Island colonies are in rapid decline. In particular, the number of breeding birds on the Oreti and... read more

Recommended citation

Burger, J., Gochfeld, M., Garcia, E.F.J. & Boesman, P. (2017). Black-billed Gull (Larus bulleri). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/53993 on 22 November 2017).