Justification of Red List Category
Although this species may have a small 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 may be small, 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.
The global population size has not been quantified, but this species is described as 'fairly common' (Stotz et al. 1996). In view of its small range, it is conceivable that the population numbers below 10,000 mature individuals; it is here tentatively placed in the band 2,500-9,999 mature individuals.
Based on the spatial spread of records (per eBird 2021) the species likely forms at least two subpopulations.
Due to the species's preference for secondary and bushy vegetation along forest edges, there is no evidence that either population size or habitat availability are currently in decline. Tree cover loss is negligible within the range (1% over ten years; Global Forest Watch 2021, using Hansen et al.  data and methods disclosed therein). The species is suspected to be stable and not at risk.
The species is endemic to the coastal ranges of northern Venezuela.
Conservation Actions Underway
The species occurs in Henri Pittier and Macarao national parks.
Conservation Actions Proposed
Quantify the population size. Investigate the species's ecology, behaviour and subpopulation structure. Monitor the population trend.
Text account compilers
Butchart, S. & Ekstrom, J.
BirdLife International (2022) Species factsheet: Synallaxis castanea. Downloaded from http://www.birdlife.org on 11/08/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 11/08/2022.