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 |
---|---|---|
2022 | Near Threatened | C2a(i) |
2016 | Vulnerable | B1ab(i,ii,iii,v);C2a(i) |
2013 | Vulnerable | B1ab(i,ii,iii,v);C2a(i) |
2012 | Vulnerable | B1ab(i,ii,iii,v);C2a(i) |
2008 | Vulnerable | B1a+b(i,ii,iii,v); C2a(i) |
2004 | Vulnerable | |
2000 | Vulnerable | |
1996 | Vulnerable | |
1994 | Vulnerable | |
1988 | Lower Risk/Least Concern |
Migratory status | not a migrant | Forest dependency | high |
Land-mass type |
continent |
Average mass | - |
Estimate | Data quality | |
---|---|---|
Extent of Occurrence (breeding/resident) | 258,000 km2 | medium |
Area of Occupancy (breeding/resident) | 17,000 km2 | |
Severely fragmented? | no | - |
Estimate | Data quality | Derivation | Year of estimate | |
---|---|---|---|---|
Population size | 7300-8000 mature individuals | poor | estimated | 2022 |
Population trend | decreasing | poor | suspected | 2016-2026 |
Rate of change over the past 10 years/3 generations (longer of the two periods) | 1-9% | - | - | - |
Rate of change over the future 10 years/3 generations (longer of the two periods) | 1-9% | - | - | - |
Rate of change over the past & future 10 years/3 generations (longer of the two periods) | 1-9% | - | - | - |
Generation length | 3.26 years | - | - | - |
Number of subpopulations | 11-100 | - | - | - |
Percentage of mature individuals in largest subpopulation | 1-89% | - | - | - |
Population justification: Field surveys in the Tapichalaca Reserve, Ecuador, found the species to occur at a density of 1 individual/km2 (Harris et al. 2008, Renjifo et al. 2014). Assuming that this density is representative for the entire range, and further precautionarily assuming that only 50% of forested habitat within the range is occupied (i.e. 50% of 11,000-12,000 km2; Global Forest Watch 2022), the total population may number 11,000-12,000 individuals. This is roughly equivalent to 7,300-8,000 mature individuals.
Trend justification: The population trend has not been quantified directly, but it is feared that the population is declining as a consequence of habitat loss within the range. Tree cover loss within the range is currently low (<2% over ten years; Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). Even though it may also be found in tall secondary forest and along natural gaps, the species is restricted to humid forest (Zimmer and Isler 2020), and thus population declines may be aggravated by additional habitat degradation. Nevertheless, it is unlikely that declines exceed 10% over ten years.
Country/Territory | Presence | Origin | Resident | Breeding visitor | Non-breeding visitor | Passage migrant |
---|---|---|---|---|---|---|
Colombia | extant | native | yes | |||
Ecuador | extant | native | yes | |||
Peru | extant | native | yes |
Country/Territory | IBA Name |
---|---|
Colombia | La Planada Natural Reserve |
Colombia | Munchique Natural National Park and southern extension |
Colombia | Parque Nacional Natural Tatamá |
Colombia | Reserva Natural Río Ñambí |
Colombia | Reserva Natural Tambito |
Ecuador | Cordillera de Huacamayos-San Isidro-Sierra Azul |
Ecuador | Corredor Ecológico Llanganates-Sangay |
Ecuador | El Ángel - Cerro Golondrinas and surrounding areas |
Ecuador | Parque Nacional Sangay |
Ecuador | Parque Nacional Sumaco-Napo Galeras |
Ecuador | Territorio Étnico Awá y alrededores |
Habitat (level 1) | Habitat (level 2) | Importance | Occurrence |
---|---|---|---|
Forest | Subtropical/Tropical Moist Montane | major | resident |
Altitude | 900 - 2530 m | Occasional altitudinal limits |
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%) | Negligible declines | Low Impact: 4 | ||||||
|
|||||||||
Agriculture & aquaculture | Annual & perennial non-timber crops - Small-holder farming | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
|||||||||
Agriculture & aquaculture | Livestock farming & ranching - Agro-industry grazing, ranching or farming | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
|||||||||
Biological resource use | Logging & wood harvesting - Unintentional effects: (large scale) [harvest] | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
|||||||||
Energy production & mining | Mining & quarrying | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Negligible declines | Low Impact: 4 | ||||||
|
|||||||||
Residential & commercial development | Housing & urban areas | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Negligible declines | Low Impact: 4 | ||||||
|
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Transportation & service corridors | Roads & railroads | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Negligible declines | Low Impact: 4 | ||||||
|
Recommended citation
BirdLife International (2024) Species factsheet: Bicolored Antvireo Dysithamnus occidentalis. Downloaded from
https://datazone.birdlife.org/species/factsheet/bicolored-antvireo-dysithamnus-occidentalis 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.