Justification of Red List category
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km² or Area of Occupancy <2,000 km² combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to 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 population size has not been quantified, but the species has been described as "common" (Whitney et al. 2013).
Trend justification
Over the last ten years to 2020, approximately 3% of tree cover with at least 50% canopy cover was lost from within the species's known range (Global Forest Watch 2021). Projecting forwards, up to 5% may be lost over the next decade. The population size is therefore suspected to be decreasing, at a rate of less than 10% per decade.
Herpsilochmus stotzi is found in central Amazonian Brazil, east of the Rio Madeira in the Aripuanã-Machado (or Ji-Paraná) interfluvium in Brazil (Whitney et al. 2013). It occurs west of the Rio Aripuanã, upriver to its confluence with the Rio Roosevelt, and on both banks of the Rio Roosevelt. The eastern limit of the distribution is not known, but is probably at least as far east as the Rio Aripuanã, and not as far east as the Rio Sucunduri in the state of Amazonas. The southern limit of the distribution is also unknown, but the range extends south into Mato Grosso and west into Rondônia.
It occurs in campinarana low, white-sand forest and patchily in tall, undisturbed terra firme forest (Whitney et al. 2013), including degraded and secondary forest. It is often associated with dense stands of the understory palm Lepidocaryum tenue (Whitney et al. 2013). It feeds on insects and spiders.
Much habitat within the range current remains intact, however the 'Transamazonica' federal highway BR-230 dissects the distribution of the species and is undoubtedly opening up additional areas to deforestation through conversion to agriculture.
It has been recorded in the Jaru Reserve (Fernandes 2013).
Text account compilers
Wheatley, H.
Contributors
Khwaja, N.
Recommended citation
BirdLife International (2024) Species factsheet: Aripuana Antwren Herpsilochmus stotzi. Downloaded from
https://datazone.birdlife.org/species/factsheet/aripuana-antwren-herpsilochmus-stotzi on 24/11/2024.
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 24/11/2024.