Acre Antshrike Thamnophilus divisorius


Justification of Red List category
Although this species may have a restricted range, it is not believed to approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Population justification
The global population size has not been quantified, but the species is believed to be common despite its restricted known range.

Trend justification
This population is suspected to be stable in the absence of evidence for any declines or substantial threats.

Distribution and population

This species was recently described from within the Parque Nacional da Serra do Divisor, Acre, Brazil. This large and relatively well protected area contains the sole known locality for this species, the Serra da Jaquirana, the easternmost of a series of narrow ridges in the Serra do Divisor, part of the Acre Arch. It may occur on physiognomically similar ridges within the Acre Arch perhaps extending to the continuous Aierra Contamana in Ucayali, Peru. Given that the species is conspicuous, the lack of records from structurally favourable Amazon Caatinga habitats c. 100 km east-southeast of the type locality suggests it is absent from that area.


The species favours stunted ridge woodlands with a broken canopy and thick understorey growing on very thin soils.


Text account compilers
Bird, J., Butchart, S.

Recommended citation
BirdLife International (2023) Species factsheet: Thamnophilus divisorius. Downloaded from on 05/12/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from on 05/12/2023.