Lesser Rhea Rhea pennata


Justification of Red List Category
This species has a very large range, and hence does not 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). The population size has not been quantified, 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). 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). For these reasons the species is evaluated as Least Concern.

Population justification
The global population size has not been quantified, but this species is described as 'uncommon' (Stotz et al. 1996).

Trend justification
The species is suspected to have undergone declines owing to the effects of hunting and egg-collection, with overgrazing perhaps being less significant but still having a negative impact.

Distribution and population

Rhea pennata (as defined following the taxonomic change) is found in west-central and southern Argentina (introduced to Tierra del Fuego in 1936) and south-eastern Chile, and inhabits shrub-steppe and floodplain grasslands from sea-level to 2,000 m (Davies 2002). It is characterised as still fairly common (del Hoyo et al. 1992, Davies 2002). Hunting and egg-collection are threats to this species, with overgrazing perhaps being less significant but still having a negative impact (Barri et al. 2008). Captive breeding projects are taking place for conservation and commercial reasons (F. Barri in litt. 2012).


The species inhabits steppe, shrubland, shrub-steppe and mallines (successional wetlands with bog, meadows and ponds) (Bellis et al. 2006), up to 1,500 m, generally breeding in upland areas with bunch-grass (del Hoyo et al. 1992). Typically found in groups of 5-30, with a male always accompanied by several females (Davies 2002). During the breeding season the females lay up to 50 eggs in a single nest, which the male alone incubates (Davies 2002).

Conservation actions

Conservation Actions Underway
CITES Appendix II.

Conservation Actions Proposed
Develop campaigns to raise awareness and reduce hunting, egg-collecting and the domestication of wild immature birds. Prevent illegal hunting and egg-collecting, while developing alternative sustainable harvesting programmes (Barri et al. 2008b). Harvest orphan eggs (eggs sporadically laid outside nests) for use in captive breeding and reintroduction programmes (Barri et al. 2008a). Maintain mallín (meadow) habitats in adequate condition as nesting sites (Bellis et al. 2006, Barri et al. 2008b, Barri et al. 2009).


92-100cm; 15-25kg. Large flightless bird of the shrub-steppe and dry grasslands in southern South America. Similar spp. Buffy-brown upperparts and more extensive white spotting than that shown by the geographically separated R. tarapacensis. Voice. During the breeding season males make a roaring noise likened to a fog-horn (Davies 2002).


Text account compilers
Benstead, P., Capper, D., Symes, A., Mazar Barnett, J., Sharpe, C J, Martin, R, Symes, A. & Taylor, J.

Knapton, B., Pearman, M. & Jaramillo, A.

Recommended citation
BirdLife International (2022) Species factsheet: Rhea pennata. Downloaded from on 28/06/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from on 28/06/2022.