NT
Black-billed Gull Larus bulleri



Family: Laridae (Gulls, Terns, Skimmers)

Authority: Hutton, 1871

Red List Category

Criteria: A2b+4b

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Justification of Red List category
Inconsistencies and a lack of transparency in the methods used to census the population in the past have meant that it is difficult to assess changes in this species's population size. Some past analyses have indicated a rapid decline, but a more recent analysis concluded that it is unlikely to have undergone a severe decline over recent decades, and is probably slightly declining or stable. Therefore, although the species is unlikely to have undergone a large population reduction over the past three generations, there is a large amount of uncertainty. For this reason, the species is listed as Near Threatened.



Population size: 90000-121000

Population trend: Unknown

Extent of occurrence (breeding/resident): 382,000 km2

Country endemic: Yes

Attributes
Land-mass type - oceanic island
Realm - Oceanic
IUCN Ecosystem -- Freshwater biome
IUCN Ecosystem -- Terrestrial biome
IUCN Ecosystem -- Marine biome

Recommended citation
BirdLife International (2021) Species factsheet: Larus bulleri. Downloaded from http://www.birdlife.org on 23/04/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 23/04/2021.