LC
Ancient Antwren Herpsilochmus gentryi



Justification

Justification of Red List Category
This species has a very large range as calculated by a Minimum Convex Polygon, and hence does not 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). 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). Therefore, this species is now listed as Least Concern.

Population justification
The population size of this species has not been quantified, but it is described as locally common in general, being rare and local in Ecuador but locally fairly common in Peru.

Trend justification
This species is suspected to lose 3.5% 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). Although susceptible to fragmentation and/or edge effects, it is therefore suspected to decline by <25% over three generations.

Distribution and population

Herpsilochmus gentryi occurs in the Marañón, Tigre, Corrientes, Pucacuro and Pastaza drainages in north-central Peru (Loreto) and east Ecuador (Pastaza), where it is common at a moderate number of sites since its discovery in the mid-1990s. It was previously thought to occur only in two rare and patchy types of terra firme forest, growing on hill-top nutrient-poor soils, but a third type is apparently inhabited in Ecuador.

Ecology

It occurs in canopy and subcanopy of humid tropical forest up to 200 m. Apparently restricted to terra firme forest growing on nutrient-poor podzolic or quartzitic soils, as well as on high, dry ridgetops.

Threats

In the Iquitos area, Peru, an increasing amount of its habitat is being cleared owing to human population growth. Much of the remainder of its range is remote and subject to little human pressure.

Conservation actions

Conservation Actions Underway
It is well protected in Ecuador, by the Kapawi Ecological Reserve, whilst the Allapahuayo-Mishana Reserved Zone in Peru encompasses large areas of suitable habitat.

Conservation Actions Proposed
Conduct surveys of suitable habitats within and surrounding the known range to determine its true distribution and abundance. Increase the area of suitable habitat that has protected status, particularly near Iquitos.

Identification

Acknowledgements

Text account compilers
Sharpe, C.J., Butchart, S., Westrip, J., Gilroy, J.


Recommended citation
BirdLife International (2018) Species factsheet: Herpsilochmus gentryi. Downloaded from http://www.birdlife.org on 24/06/2018. Recommended citation for factsheets for more than one species: BirdLife International (2018) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/06/2018.