email a friend
printable version
VU
Bicoloured Antvireo Dysithamnus occidentalis

IUCN Red List Criteria

Critically Endangered  
Endangered  
Vulnerable B1ab(i,ii,iii,v);C2a(i) 

IUCN Red List history

Year Category
2013 Vulnerable
2012 Vulnerable
2008 Vulnerable
2004 Vulnerable
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
1988 Lower Risk/Least Concern

Species attributes

Migratory status not a migrant Forest dependency High
Land mass type continent
Average mass -

Distribution

  Estimate Data quality
Extent of Occurrence breeding/resident (km2) 7,600 medium
Number of locations 10-12 -
Fragmentation -

Population & trend

  Estimate Data quality Derivation Year of estimate
No. of mature individuals 1500-7000 poor Estimated 2000
Population trend Decreasing poor -
Number of subpopulations 2-100 - - -
Largest subpopulation 251-1000 - - -
Generation length (yrs) 4.8 - - -
Population justification: The population is estimated to number 2,500-9,999 individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.
Trend justification: This species's population is suspected to be declining rapidly, in line with rates of habitat loss within its range.

Country/Territory distribution

Country/Territory Occurrence status Presence Breeding Non-breeding Passage
Colombia Native Extant      
Ecuador Native Extant      

Important Bird Areas where this species has triggered the IBA criteria

Country/Territory IBA Name IBA link
Colombia Munchique Natural National Park (Parque Nacional Natural Munchique IBA) site factsheet
Colombia Parque Nacional Natural Tatamá site factsheet
Colombia Reserva Natural El Pangán site factsheet
Colombia Reserva Natural Río Ñambí site factsheet
Colombia Reserva Natural Tambito site factsheet
Colombia Serranía de los Paraguas site factsheet
Ecuador Cordillera de Huacamayos-San Isidro-Sierra Azul site factsheet
Ecuador Corredor Ecológico Llanganates-Sangay site factsheet
Ecuador El Ángel-Cerro Golondrinas site factsheet
Ecuador Parque Nacional Sangay site factsheet
Ecuador Parque Nacional Sumaco-Napo Galeras site factsheet
Ecuador Territorio Étnico Awá y alrededores site factsheet

Habitats & altitude

Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Montane major resident
Altitude 900 - 2200 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 Decline Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Annual & perennial non-timber crops / Small-holder farming Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Decline Medium Impact:
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 Decline Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting / Unintentional effects: (large scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Decline Medium Impact:
Stresses
Ecosystem degradation, Ecosystem conversion
Energy production & mining Mining & quarrying Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Decline Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Residential & commercial development Housing & urban areas Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Decline Medium Impact:
Stresses
Ecosystem degradation, Ecosystem conversion
Transportation & service corridors Roads & railroads Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Decline Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2014) Species factsheet: Dysithamnus occidentalis. Downloaded from http://www.birdlife.org on 22/07/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 22/07/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Vulnerable
Family Thamnophilidae (Antbirds)
Species name author (Chapman, 1923)
Population size 1500-7000 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 7,600 km2
Country endemic? No
Links to further information
- Summary information on this species