South-eastern Uruguay (R de la Plata) to Argentina (Puerto Deseado), but breeding known only in Argentina (Buenos Aires, Chubut).
Rarity Status
Currently this species is not classified as a rarity in this country OR information has not been updated.
Population
Estimated population is 7,000 (2010) and decreasing.
Status NT
One of the main breeding areas, Bahia Bianca, is subject to extreme human disturbance including development, industry, agriculture, fishing and pollution. Egg collecting is also a threat.
For more information see BirdLife International Species Factsheet.
Food
Crabs and also molluscs, snails, small fish, insects, garbage, fish discards.
Olrog's Gull (Larus atlanticus) [XC393314]
by id from Bah\u00eda Blanca, Bah\u00eda Blanca, Buenos Aires, Argentina (alarm call)
Olrog's Gull (Larus atlanticus) [XC51186]
by Pablo Petracci from Albufera Mar Chiquita, Buenos Aires, Argentina (song)
Subspecies
Originally described as a subspecies of Belcher's Gull (Larus belcheri), but now almost universally considered a distinct species.
No subspecies.
Similar Species
Kelp Gull (Larus dominicanus) is slightly larger with a wholly white tail as well as no subterminal band on the bill and white tips on the primaries.
References
See References.
BirdLife International Species Factsheet