Data Zone
Justification of Red List category
This species qualifies as Near Threatened as its population is suspected to be declining at a rate approaching the threshold for classification as Vulnerable, mainly as a consequence of the loss and fragmentation of its habitat and hunting.
Population justification
The global population size has not been quantified, but this species is described as 'uncommon to fairly common' (Stotz et al. 1996).
Trend justification
The population is reportedly declining, mainly as a consequence of habitat loss and fragmentation, as well as hunting (Giordano et al. 2010, Bazzano et al. 2014, Kirwan et al. 2021). It has become extinct in Ceará and Rio Grando do Norte in northern Brazil, though parts have now been recolonised by reintroduced individuals (Kirwan et al. 2021).The rate of decline has not been quantified, but it is suspected to be moderately rapid over three generations (33.2 years; Bird et al. 2020) as a consequence of continuing pressures from habitat loss and hunting.
Rhea americana has a large range in eastern and southern South America, ranging from northeast Brazil, east and northeast Bolivia, Paraguay, Uruguay to north-east and east Argentina south to the Río Negro (Folch 1992, Kirwan et al. 2021). It has declined markedly and the healthiest populations are now believed to be in parts of the Chaco region (Folch 1992).
It prefers open landscapes with a simple structure and low vegetation, such as pampas, campo cerrado and open chaco woodland, but is also found in cultivated fields (Canevari et al. 1991, Folch 1992, Sick 1993, Parker et al. 1996, García-Eriza and Gómez-Villafañe 2016). Population densities in grassland are several times that in agricultural areas, and birds were found to occupy 51% of a grassland area, but less than 5% of an agricultural locality (Giordano et al. 2008). It breeds in areas with dense vegetation cover of tall grasses (García-Eriza and Gómez-Villafañe 2016, G. J. Fernández in litt. 2020). Eggs are laid on the ground in an area of trampled grass; the male incubates the eggs alone and raises the young (Kirwan et al. 2021). Food items include insects and grasses (Kirwan et al. 2021).
Its status is obfuscated by the presence of feral birds (Lowen et al. 1996), but the population has declined markedly mainly owing to hunting for meat and eggs, and the colossal export of skins and, to a lesser extent, plumes. Over 50,000 skins were traded in 1980, most apparently originating in Paraguay, with Japan and USA leading consumers (Folch 1992). Hunting has reportedly contributed to local declines and extinctions (Kirwan et al. 2021).
In recent years, the large-scale conversion of central South American grasslands for agriculture and cattle-ranching has considerably reduced and fragmented its available habitat, particularly in the pampas and cerrado strongholds; this is causing declines and increasing isolation of the remaining population (da Silva 1995, Bazzano et al. 2014, Kirwan et al. 2021).
Conservation Actions Underway
CITES Appendix II. Captive-bred individuals are being reintroduced in parts of their native range (Vera-Cortez et al. 2018).
Text account compilers
Hermes, C.
Contributors
Benstead, P., Capper, D., Fernández, G., Sharpe, C.J. & Symes, A.
Recommended citation
BirdLife International (2024) Species factsheet: Greater Rhea Rhea americana. Downloaded from
https://datazone.birdlife.org/species/factsheet/greater-rhea-rhea-americana on 22/12/2024.
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 22/12/2024.