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Bahia Antwren Herpsilochmus pileatus



Justification

Justification of Red List category
This species is thought to have a small population, which is scattered in isolated subpopulations, and is declining as a consequence of continued habitat loss and fragmentation. For these reasons it is evaluated as Near Threatened.

Population justification
The population size has not been quantified, but the species is described as locally common (Zimmer et al. 2020). Assuming that the species occurs at the same density as two congeners (H. stictocephalus and H. sticturus: 2-5 mature individuals/km2; Santini et al. 2018), and assuming that 50% of forests within the range are occupied (i.e., 2,100-2,600 km2; Global Forest Watch 2022), the population may number 4,200-13,000 mature individuals.

Trend justification
There are no data on the population trend, but due to the species' specific habitat requirements declines are suspected on the basis of ongoing forest loss and degradation.
Over ten years, 9% of tree cover is lost within the range (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). As the species has limited dispersal abilities and is confined to small, isolated subpopulations in disjunct patches of restinga forest (ICMBio 2018), population declines may be steeper than the rate of tree cover loss suggests due to increasing fragmentation between occupied patches. Tentatively, population declines are here placed in the band 10-19% over ten years.

Distribution and population

Herpsilochmus pileatus occurs along the coast of Bahia, Brazil.

Ecology

This species occupies the canopy layer and mid-storey of forests and restinga woodland (del Hoyo et al. 2003, Zimmer et al. 2020). It feeds on insects, but its ecology is largely unknown (Zimmer et al. 2020).

Threats

Coastal forests in Bahia have suffered tremendous reduction in size during the last few decades. Logging companies and conversion to pastures are among the factors that have contributed to the deforestation process. The species has a limited range, and although common, remaining vegetation is still being destroyed.

Conservation actions

Conservation Actions Underway
It occurs in several protected areas across its range, including Descobrimento, Monte Pascoal and Pau Brasil national parks.

Conservation Actions Proposed
Produce an accurate quantification of the population size. Research the species' ecology and behaviour. Monitor the population trend. Monitor rates of habitat loss. Secure the adequate protection of key sites.

Identification

11 cm. Small, rather short-tailed antwren. Males are grey with black cap, thick black eyestripe and black, white-tipped wing coverts and tail feathers. Females are similar but have buffy foreheads, white streaking in the crown and dirty white underparts washed with buff in the breast. Similar spp. Males told from sympatric Black-capped Antwren H. atricapillus by large bill, much shorter tail and greyer underparts. Females have less buff in underparts (restricted largely to breast). Voice 4-7 notes separated by decreasing intervals which eventually merge into a regular series.

Acknowledgements

Text account compilers
Hermes, C.

Contributors
Benstead, P., De Luca, A., Develey, P., Pacheco, J.F., Phalan, B., Pople, R., Sharpe, C.J., Subirá, R., Symes, A. & Wege, D.


Recommended citation
BirdLife International (2024) Species factsheet: Bahia Antwren Herpsilochmus pileatus. Downloaded from https://datazone.birdlife.org/species/factsheet/bahia-antwren-herpsilochmus-pileatus on 23/11/2024.
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 23/11/2024.