Justification of Red List Category
This recently described species is likely to have a very small population. For this reason the species is assessed as Vulnerable.
Uncommon and local. The population is estimated to number 1,000-2,499 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 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals.
This species is suspected to lose 7% of suitable habitat within its distribution over three generations (14 years) based on a model of Amazonian deforestation (Soares-Filho et al. 2006, Bird et al. 2011). Given the susceptibility of the species to fragmentation and/or edge effects, it is therefore suspected to decline by <25% over three generations.
Percnostola arenarum is known only from Loreto in Peru, from the drainage of the Rio Nanay west to the Rio Tigre, including Nauta on the bank of the Rio Marañón between those two rivers (Isler et al. 2001). The Nauta specimen, at the Museum of Natural History, had previously been tentatively assigned to P. rufifrons jensoni (Capparella et al. 1997).
P. arenarum is found in dense, stunted terra firme forest on white sandy soil (a habitat named 'varillal' by local people), with an understorey dominated by the saplings of white sand specialists. It appears to be restricted to this habitat type, although it was also found, albeit extremely locally, in a nutrient-poor habitat termed 'irapayal' comprising taller forest with a dense understorey of irapay palm, which grows on very old, weathered clay soils as well as sandy soils (Isler et al. 2001).
Based on current knowledge about this species, it has a very specialised habitat niche and a very small geographic range. The habitats in which it is found are subject to intense human activity in a region of rapid population growth. Varillal is heavily exploited for poles for building houses, and the leaves of the irapay palm are extensively harvested to make thatched roofs (Isler et al. 2001). The impact of these threats is exacerbated by the fact that the species has only been found in certain 'varillales', and even fewer 'irapayales', despite intense ornithological surveying (Isler et al. 2001). Despite protection, 200 people have entered the reserve and carved out homesteads, engaging in activities like illegal hunting and illegal road building and logging which destroys habitat (J. Alonso Alvarez in litt. 2003).
Conservation Actions Underway
The establishment of the Allpahuayo-Mishana National Reserve (initially as a Reserved Zone) in 1999, which includes much of the known range of P. arenarum, was a critical step in the protection of this species. This must be followed by the resources required to manage the area (Isler et al. 2001) and enforce existing legislation.
10 cm. A small, sexually dichromatic antbird. Male dark grey with black throat and wing coverts (the latter fringed with white). Female has dark grey upperparts with black wing coverts (fringed reddish-brown), and underparts reddish-brown and white. Similar spp. Male lacks black crown of Black-headed Antbird P. rufifrons, and female shows strong contrast between reddish-brown of majority of the underparts and clear white belly patch, chin and throat. Voice Song a series of similar notes that decelerate in pace (especially initially).
Text account compilers
Benstead, P., Harding, M., Sharpe, C.J., Symes, A., Westrip, J., Wheatley, H., Hermes, C.
Alonso Alvarez, J.
BirdLife International (2019) Species factsheet: Percnostola arenarum. Downloaded from http://www.birdlife.org on 16/06/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/06/2019.