Stresemann's Bristlefront Merulaxis stresemanni


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: #

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
B1ab(i,ii,iii,v);C2a(i,ii);D B1ab(i,ii,iii,v);C2a(i,ii);D A2c+3c+4c;B1ab(i,ii,iii,v);C2a(i,ii);D1

Red List history
Year Category Criteria
2018 Critically Endangered B1ab(i,ii,iii,v);C2a(i,ii);D
2016 Critically Endangered B1ab(i,ii,iii,v);C2a(i,ii);D
2013 Critically Endangered B1ab(i,ii,iii,v);C2a(i,ii);D
2012 Critically Endangered B1ab(i,ii,iii,v);C2a(i,ii);D
2010 Critically Endangered B1a+b(i,ii,iii,v); C2a(ii)
2009 Critically Endangered B1a+b(i,ii,iii,v); C2a(ii)
2008 Critically Endangered
2006 Critically Endangered
2005 Critically Endangered
2004 Critically Endangered
2000 Critically Endangered
1996 Critically Endangered
1994 Critically Endangered
1988 Threatened
Species attributes

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

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 29 medium
Number of locations 1 -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 1-49 poor estimated 2011
Population trend Decreasing poor suspected -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 30-49 - - -
Decline (10 years/3 generation past and future) 30-49 - - -
Number of subpopulations 1 - - -
Percentage in largest subpopulation 100 - - -

Population justification: In the Jequitinhonha valley (the sole currently known population), at least four birds were found in a 100 ha area, but it was thought unlikely that this density could be extrapolated for the whole 5,000 ha partly fragmented patch of forest (R. Ribon in litt. 2006). Surveys of the Macarani / Bandeira area near Balbina (Sossego do Arrebol Forest) found just six individuals: five females and a single male (Fundação Biodiversitas in litt. 2010). Three males were recorded in 2012 (WikiAves 2013) but there are likely no more than 10-15 birds in total and none have been found in other forest fragments surveyed (R. Ribon in litt. 2011). It is therefore now suspected that there may be fewer than 50 birds remaining, and the population is placed in the band 1-49 mature individuals.

Trend justification: The species is suspected to be in decline based on rates of habitat loss and degradation.

Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Brazil N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Brazil Una
Brazil Bandeira / Macarani
Brazil Fazenda Jueirana

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Artificial/Terrestrial Subtropical/Tropical Heavily Degraded Former Forest suitable resident
Forest Subtropical/Tropical Dry major resident
Altitude 0 - 930 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Scale Unknown/Unrecorded Timing Scope Severity Impact
Ongoing Whole (>90%) Rapid Declines High Impact: 8
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Livestock farming & ranching - Agro-industry grazing, ranching or farming Timing Scope Severity Impact
Ongoing Whole (>90%) Rapid Declines High Impact: 8
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Ecosystem degradation
Natural system modifications Fire & fire suppression - Increase in fire frequency/intensity Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Ecosystem degradation

Recommended citation
BirdLife International (2021) Species factsheet: Merulaxis stresemanni. Downloaded from on 24/10/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from on 24/10/2021.