Data Zone
Justification of Red List category
A recent rediscovery and three subsequent records at different sites have led to this formerly Data Deficient species being re-evaluated (Collar et al. 1992). It is now classified as Near Threatened, because it is thought to have a moderately small population which is declining owing to habitat loss and fragmentation associated with infrastructure development. The known range is small, but it may well occur more widely. Further data may leads to its downlisting to Least Concern in future.
Population justification
Given its relatively small range and specialised habitat requirements, there are thought to be less than 10,000 individuals, and so it is placed in the band 2,500-9,999 individuals. This equates to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.
Trend justification
This species is suspected to lose 2.7% of suitable habitat within its distribution over three generations (18 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.
Pithys castaneus was known from a single specimen collected in September 1937 in the Amazonian forest lowlands, at Andoas on the lower río Pastaza, in what is now Peru. It was rediscovered in July 2001 on the río Morona in western Loreto, northern Peru, and field photographs and specimens were obtained (T. S. Schulenberg in litt. 2002). It has since been found c.116 km to the south-west, near Chicais, Amazonas, a village on the west bank of the Marañon, and has also been collected on the north bank of the Marañon river, east of the Kanpankis Range, south of Tierra Blanca (J. Alvarez in litt. 2007). The type-locality is a source of confusion, but it has recently been suggested that it may refer to the Tunigrama River, which was known for hundreds of years as the Andoas River (T. Mark in litt. 2007).
It is an obligate ant-follower of the understorey of low elevation forest. It was rediscovered in an area of varillal and was thought perhaps to be a white-sand specialist, although it was also twice observed in hilly terra firme, c. 300m from varillal. The second site where it was recorded consists of hilly terra firme on heavily leached, and therefore rather poor, soil.
Rates of habitat loss within its known range are poorly known, but its habitat has been damaged by the construction of an oil pipeline, and several roads are planned. Obligate ant-followers are usually some of the first species to be lost from fragmented forests so this species is likely to be declining due to these pressures.
Conservation Actions Underway
None is known. The west bank of the Rio Morona are part of the Zona Reservada Santiago Comaina, created in 1999 (Lane et al. 2006).
Voice Repetitive descending cheeeeurrr calls.
Text account compilers
Mahood, S., Harding, M., Sharpe, C.J., Benstead, P., Isherwood, I.
Contributors
Mark, T., Lane, D., Schulenberg, T., Alvarez, J.
Recommended citation
BirdLife International (2024) Species factsheet: White-masked Antbird Pithys castaneus. Downloaded from
https://datazone.birdlife.org/species/factsheet/white-masked-antbird-pithys-castaneus on 22/11/2024.
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 22/11/2024.