LC
Lesser Rhea Rhea pennata



Taxonomy

Taxonomic note

Rhea pennata and R. tarapacensis (del Hoyo and Collar 2014) were previously lumped as R. pennata following Sibley and Monroe (1990, 1993), but now lumped again as R. pennata largely on the basis that solid evidence of its specific distinctiveness is not available (Handbook of the Birds of the World and BirdLife International 2022). However, type description claiming different tarsal scutellation has apparently not been refuted; further work needed. Previously placed in genus Pterocnemia, on basis mainly of tarsal scutellation and feathered upper tarsus, but genetic studies reveal close relationship with R. americana, and probably more aptly considered congeneric (Delsuc et al. 2007, SACC 2008); has hybridized with R. americana in captivity. Three subspecies recognised.

Taxonomic source(s)
Handbook of the Birds of the World and BirdLife International. 2022. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 7. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v7_Dec22.zip.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2022 Least Concern
2016 Not Recognised
2014 Not Recognised
2012 Near Threatened A2cd+3cd+4cd
2008 Near Threatened A2c,d; A3c,d; A4c,d
2004 Near Threatened
2000 Lower Risk/Near Threatened
1994 Lower Risk/Near Threatened
1988 Near Threatened
Species attributes

Migratory status not a migrant Forest dependency does not normally occur in forest
Land-mass type continent
Average mass -
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 2,600,000 km2 medium
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size unknown - - -
Population trend decreasing poor suspected -
Generation length 11.89 years - - -
Number of subpopulations 3-100 - - -
Percentage of mature individuals in largest subpopulation 1-89% - - -

Population justification: The global population size has not been quantified. The subspecies pennata is described as locally fairly common (Schmitt et al. 2022). Considering the number of observational records (see eBird 2022), the population is likely very large.
The combined population of the two subspecies tarapacensis and garleppi is likely smaller. It has been suggested that the total population of both subspecies is as low as several hundred birds. In 1983, the Peruvian population was estimated at 18 individuals, with very low numbers in northern Chile (principally in Lauca National Park [A. Jaramillo in litt. 1999]) and on the altiplano in Bolivia. These figures are now generally thought to be too low, with 'at least many hundreds' in Chile from the Peruvian border to the Antofagasta highlands alone (A. Jaramillo in litt. 2014), while the population in Peru is estimated at 350 individuals (SERFOR 2018). A preliminary estimate is that the combined population of tarapacensis and garleppi could lie within the range 1,000-2,499 mature individuals, but this requires confirmation.

Trend justification: The species is suspected to undergo a decline, driven by habitat loss through conversion for agriculture and human settlements, overgrazing, hunting and egg-collection.


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Argentina extant native yes
Bolivia extant native yes
Chile extant native yes
Peru extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Argentina Area Natural Protegida Auca Mahuida
Argentina Area Natural Protegida El Mangrullo
Argentina El Zurdo
Argentina Estancia El Cóndor
Argentina Extensión Límite Este y Sur del Parque Nacional Nahuel Huapi
Argentina La Angostura y Alto Río Chico
Argentina Lagunillas
Argentina Llanos de Jagüé
Argentina Meseta de Somuncura Provincial Natural Protected Area
Argentina Meseta del Asador (o Aguila)
Argentina Meseta Lago Buenos Aires
Argentina Meseta Lago Strobel
Argentina Monumento Natural Bosques Petrificados y Estancia El Cuadro
Argentina Monumento Natural Laguna de Los Pozuelos
Argentina Nahuel Huapi National Park and Reserve
Argentina Parque Nacional El Leoncito
Argentina Parque Nacional Laguna Blanca
Argentina Parque Nacional Los Glaciares y adyacencias (Estancias El Sosiego, La Soledad y Anita)
Argentina Parque Nacional Perito Moreno y Reserva Provincial San Lorenzo
Argentina Parque Nacional Talampaya
Argentina Paso de los Indios
Argentina Reserva de la Biosfera Parque Nacional San Guillermo
Argentina Reserva Provincial El Payén
Argentina Reserva Provincial Laguna Brava
Argentina Reserva Provincial Laguna de Llancanelo
Argentina Reserva Provincial Olaroz-Cauchari
Argentina Reserva Provincial y de la Biosfera Laguna Blanca
Argentina San Antonio Oeste
Argentina Sistema de lagunas de Vilama-Pululos
Argentina Socompá-Llullaillaco
Argentina Valle del Río Collón Curá
Bolivia Lago Poopó y Río Laka Jahuira
Bolivia Lago Titicaca (Sector Boliviano)
Bolivia Lagunas de Agua Dulce del Sureste de Potosí
Bolivia Lagunas Salinas del Suroeste de Potosí
Bolivia Parque Nacional Sajama
Chile Chacabuco Valley and Baker River Entrance
Chile Marisma Buque Quemado
Chile Parque Nacional Torres del Paine
Peru Covire

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Grassland Subtropical/Tropical High Altitude suitable resident
Grassland Temperate suitable resident
Shrubland Subtropical/Tropical Dry suitable resident
Wetlands (inland) Alpine Wetlands (includes temporary waters from snowmelt) suitable resident
Wetlands (inland) Bogs, Marshes, Swamps, Fens, Peatlands marginal resident
Wetlands (inland) Permanent Saline, Brackish or Alkaline Lakes marginal resident
Altitude 0 - 4500 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Agro-industry farming Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Annual & perennial non-timber crops - Small-holder farming Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Livestock farming & ranching - Agro-industry grazing, ranching or farming Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Livestock farming & ranching - Small-holder grazing, ranching or farming Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Reduced reproductive success, Species mortality
Residential & commercial development Housing & urban areas Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion

Utilisation
Purpose Scale
Food - human subsistence, national
Handicrafts, jewellery, etc. national, international

Recommended citation
BirdLife International (2024) Species factsheet: Lesser Rhea Rhea pennata. Downloaded from https://datazone.birdlife.org/species/factsheet/lesser-rhea-rhea-pennata on 23/12/2024.
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 23/12/2024.