Data Zone
Justification of Red List category
This species has a large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence under 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). 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 (under 10,000 mature individuals with a continuing decline estimated to be over 10% in ten years or three generations, or with a specified population structure). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (over 30% decline over ten years or three generations). For these reasons the species is evaluated as Least Concern.
Population justification
The global population size is estimated at 42,744-82,000 individuals (Wetlands International 2023), which equates to 28,500-54,700 mature individuals. The overall population trend is considered to be stable over three generations (24.6 years) (Wetlands International 2023).
Trend justification
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This species breeds on northern Tierra del Fuego Island (Chile and Argentina) and southern Santa Cruz, wintering in southern Buenos Aires, Argentina; there is also a virtually sedentary population on the Falkland Islands (Malvinas) (del Hoyo et al. 1992).
The species is found in open country, frequenting coastal grassland and meadows, often with Upland Goose C. picta and Ashy-headed Goose C. poliocephala (Argentina only). It feeds on roots, leaves, stems and seed-heads of grasses and sedges in natural grasslands, pastures and agricultural lands (del Hoyo et al. 1992). It nests from late September to early November in the Falklands, with nests recorded until January on Tierra del Fuego (Woods and Woods 1997, Chebez 1994).
The Argentinean federal government declared C. rubidiceps a pest in the 1960s, claiming it fed on wheat and corn crops, and competed with sheep and cattle stocks for grassland resources in Buenos Aires (Chebez 1994). Although there is no evidence to support the latter and its numbers are too few to seriously effect the former, this promoted the active destruction of the species and persecution at its wintering grounds is certainly a factor contributing to its decline. However, this is not true on the Falklands, where 100,000 were killed in the period 1905-1912 and fair numbers are still killed each year, but the mobility of the species apparently renders efforts to reduce its numbers ineffective (del Hoyo et al. 1992). It was also removed from the list of pest species (Schedule I of the 1964 Wild Animals and Bird Protection Ordinance) on the Falklands in 1985 (Woods and Woods 1997). The introduction of Patagonian Grey Fox Dusicyon griseus as a control for the European Rabbit Oryctolagus cuniculus on Tierra del Fuego is perhaps also a contributory factor in the species's decline (Chebez 1994). It is possible that the smaller sized C. rubidiceps is at some disadvantage in interspecific encounters with the larger and perhaps more aggressive C. picta leading to the displacement of C. rubidiceps from foraging and nesting sites.
Text account compilers
Rutherford, C.A.
Recommended citation
BirdLife International (2024) Species factsheet: Ruddy-headed Goose Chloephaga rubidiceps. Downloaded from
https://datazone.birdlife.org/species/factsheet/ruddy-headed-goose-chloephaga-rubidiceps on 18/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 18/12/2024.