Larus modestus


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Larus modestus
Species Authority: Tschudi, 1843
Common Name(s):
English Grey Gull, Gray Gull

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Facilitator/Compiler(s): Ekstrom, J., Butchart, S., Calvert, R.
Although this species may have a restricted range, it is not believed to approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size may be moderately small to large, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Geographic Range [top]

Range Description: The Grey Gull breeds in the extremely arid Atacama Desert in northern Chile and is present as a non-breeding visitor throughout most of the Chilean coast, excluding the south, and the coast of Peru and Ecuador1.
Chile; Colombia; Costa Rica; Ecuador; Falkland Islands (Malvinas); Peru
Present - origin uncertain:
South Georgia and the South Sandwich Islands
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: This species feeds mainly and sometimes exclusively on mole crabs, but will also feed on fish, nereid worms and offal. It will also scavenge in harbours and follow fishing boats. Its breeding season ranges from November to January, breeding in the barren montane Atacama Desert between 35 and 100 km inland. It nests is a scrape in the sand, usually near rocks, but does not breed in years with a severe occurence of El Nino (del Hoyo et al. 1996).
Systems: Terrestrial; Marine

Citation: BirdLife International 2012. Larus modestus. The IUCN Red List of Threatened Species. Version 2015.2. <>. Downloaded on 02 September 2015.
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