Data Zone
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.
| Critically Endangered | Endangered | Vulnerable |
|---|---|---|
| - | - | - |
| Year | Category | Criteria |
|---|---|---|
| 2021 | Near Threatened | A2c+3c+4c |
| 2016 | Near Threatened | A2c+3c+4c |
| 2012 | Near Threatened | A2c+3c+4c |
| 2008 | Near Threatened | A2c; A3c; A4c |
| 2004 | Near Threatened | |
| 2000 | Lower Risk/Near Threatened | |
| 1994 | Lower Risk/Near Threatened | |
| 1988 | Threatened |
| Migratory status | full migrant | Forest dependency | does not normally occur in forest |
| Land-mass type |
continent |
Average mass | 6 g |
| Estimate | Data quality | |
|---|---|---|
| Extent of Occurrence (breeding/resident) | 11,200,000 km2 | medium |
| Extent of Occurrence (non-breeding) | 9,770,000 km2 | medium |
| Severely fragmented? | no | - |
| Estimate | Data quality | Derivation | Year of estimate | |
|---|---|---|---|---|
| Population size | unknown | - | - | - |
| Population trend | decreasing | - | suspected | 2012-2022 |
| Rate of change over the past 10 years/3 generations (longer of the two periods) | 10-20% | - | - | - |
| Rate of change over the future 10 years/3 generations (longer of the two periods) | 10-20% | - | - | - |
| Rate of change over the past & future 10 years/3 generations (longer of the two periods) | 10-20% | - | - | - |
| Generation length | 2.04 years | - | - | - |
| Percentage of mature individuals in largest subpopulation | 1-89% | - | - | - |
Population justification: Although widespread and fairly common at a few localities, it is generally scarce and localised (Collar and Wege 1995, Parker and Willis 1997). Surveys in the Argentinian Pampas in 2006 to 2008 found the species to be rare, with records in only two of 30 transects (Codesido et al. 2012).
The global population size has not been quantified, but given the size of its range, it is assumed to be larger than 10,000 mature individuals (Collar and Wege 1995). The population in Argentina is suspected to number 2,500-10,000 mature individuals (MAyDS and Aves Argentinas 2017). In French Guiana, there are thought to be fewer than 250 mature individuals (MNHN et al. 2018).
Trend justification: Although there is no direct, quantitative information on population trends, the population is suspected to be in decline owing to ongoing habitat destruction and degradation.
In Colombia, habitat loss may have led the species to disappear from some areas (Ruiz-Ovalle and Chaparro-Herrera 2016), and in 2005, the species was not found at a site in Meta where it was previously recorded in the 1960s (F. G. Stiles, in Ruiz-Ovalle and Chaparro-Herrera 2016). Although an analysis of habitat change found no loss between 2001 and 2011, the species's population was suspected to have declined by more than 30% over 10.8 years due to fires and habitat conversion, with the rate of loss expected to increase in the future (Renjifo et al. 2016).
In Brazil, the population size is suspected to be declining as a result of ongoing habitat loss and degradation through conversion to agriculture and overgrazing (ICMBio 2013).
In Argentina, surveys in the pampas in 2005-2008 found that other, more common, grassland specialist bird species were present in significantly fewer counties than in 1938 to 1993 (Codesido et al. 2011). However, the species's range has expanded in La Pampa and eastern Buenos Aires since the 1980s (MAyDS and Aves Argentinas 2017).
The species's population size is suspected to be stable in the Sipaliwini Nature Reserve in south Suriname and in adjacent Brazil (O. Ottema in litt. 2020), but declining in French Guiana (MNHN et al. 2018).
Overall, the population is suspected to be declining moderately rapidly, with a rate of decline here placed in the band 10-20% over ten years, although this is highly uncertain.
| Country/Territory | Presence | Origin | Resident | Breeding visitor | Non-breeding visitor | Passage migrant |
|---|---|---|---|---|---|---|
| Argentina | extant | native | yes | yes | ||
| Bolivia | possibly extinct | native | yes | |||
| Brazil | extant | native | yes | |||
| Colombia | extant | native | yes | |||
| French Guiana | extant | native | yes | |||
| Guyana | extant | native | yes | |||
| Paraguay | extant | native | yes | |||
| Suriname | extant | native | yes | |||
| Uruguay | extant | native | yes | |||
| Venezuela | extant | native | yes |
| Habitat (level 1) | Habitat (level 2) | Importance | Occurrence |
|---|---|---|---|
| Grassland | Subtropical/Tropical Dry | major | non-breeding |
| Grassland | Subtropical/Tropical Dry | major | breeding |
| Grassland | Subtropical/Tropical Seasonally Wet/Flooded | major | non-breeding |
| Grassland | Subtropical/Tropical Seasonally Wet/Flooded | major | breeding |
| Savanna | Dry | major | non-breeding |
| Savanna | Dry | major | breeding |
| Altitude | 150 - 1350 m | Occasional altitudinal limits | (max) 1600 m |
| 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 | ||||||
|
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| 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 | ||||||
|
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| Agriculture & aquaculture | Wood & pulp plantations - Agro-industry plantations | Timing | Scope | Severity | Impact | ||||
| Ongoing | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
|
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| Energy production & mining | Mining & quarrying | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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| Energy production & mining | Renewable energy | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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| Natural system modifications | Fire & fire suppression - Increase in fire frequency/intensity | Timing | Scope | Severity | Impact | ||||
| Ongoing | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
|
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| Residential & commercial development | Commercial & industrial areas | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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| Residential & commercial development | Tourism & recreation areas | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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| Transportation & service corridors | Roads & railroads | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | Negligible declines | Low Impact: 4 | ||||||
|
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Recommended citation
BirdLife International (2024) Species factsheet: Bearded Tachuri Polystictus pectoralis. Downloaded from
https://datazone.birdlife.org/species/factsheet/bearded-tachuri-polystictus-pectoralis 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.