LC
Rufous-sided Pygmy-tyrant Euscarthmus rufomarginatus



Taxonomy

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm.

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

Red List history
Year Category Criteria
2024 Least Concern
2016 Near Threatened A2c+3c+4c
2012 Near Threatened A2c+3c+4c
2008 Near Threatened A2c; A3c; A4c
2004 Near Threatened
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
1988 Lower Risk/Least Concern
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) 5,760,000 km2 medium
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size unknown - - -
Population trend decreasing poor suspected -
Generation length 2.34 years - - -
Number of subpopulations 5-20 - - -
Percentage of mature individuals in largest subpopulation 1-89% - - -

Population justification: The global population size has not been quantified, but this species is generally described as rare and patchily distributed (Stotz et al. 1996, Fitzpatrick and Kirwan 2023). It however appears to be common locally, including in Sipaliwini (Suriname) and in Bolivia, where substantial populations remain (O. Ottema in litt. 2020, Fitzpatrick and Kirwan 2023). Density estimates range from 2.2 individuals/km2 to more than 20 individuals/km2 (Fitzpatrick and Kirwan 2023, Marini et al. 2023). Given its overall rarity, localised distribution and strict habitat requirements, an extrapolation of the population based on these estimates is not feasible (Marini et al. 2023). Nevertheless, the global population is likely large.
The species is restricted to specific habitat within the Cerrado biome, open humid grassy habitats, which are easily converted to agriculture (A. Lees in litt. 2024, E.R. Luiz in litt. 2024). Due to the loss of habitat, the population is suspected to be declining.

Trend justification: The species likely used to be more widespread, but is restricted to specific habitat within the Cerrado biome, open humid grassy habitats, which are easily converted to agriculture (A. Lees in litt. 2024, E.R. Luiz in litt. 2024). It is thought to be undergoing slow declines as a consequence of the ongoing conversion and degradation of its grassland habitat (Collar et al. 1992, Fitzpatrick and Kirwan 2023). The rate of reduction is unknown, and the rate of habitat loss relevant for the species has also not been quantified.


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Bolivia extant native yes
Brazil extant native yes
Paraguay extant native yes
Suriname extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Bolivia Cercanías de Riberalta
Bolivia Cerrado de Riberalta
Bolivia Noel Kempff Mercado
Brazil Campo do Alto Marmelos
Brazil Cerrados do Nordeste de Tocantins
Brazil Jalapão
Brazil Lizarda
Brazil Monumento Natural das Árvores Fossilizadas e Adjacências
Brazil Savanas do Amapá
Suriname Sipaliwini Nature Reserve

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Grassland Subtropical/Tropical Dry major resident
Savanna Dry major resident
Shrubland Subtropical/Tropical Dry major resident
Altitude 0 - 1160 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 Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem conversion
Agriculture & aquaculture Livestock farming & ranching - Agro-industry grazing, ranching or farming Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem conversion
Agriculture & aquaculture Wood & pulp plantations - Agro-industry plantations Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem conversion

Recommended citation
BirdLife International (2024) Species factsheet: Rufous-sided Pygmy-tyrant Euscarthmus rufomarginatus. Downloaded from https://datazone.birdlife.org/species/factsheet/rufous-sided-pygmy-tyrant-euscarthmus-rufomarginatus 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.