Data Zone
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 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 global population size has not been quantified, but this species is described as common and relatively abundant (CSS Brazil and CEMAVE-ICMBio 2020).
Trend justification
There are no recent data on the population size or trend. However, ongoing declines are suspected, owing to rates of habitat destruction and degradation within the species' range.
Over ten years, 8% of tree cover is lost within the range (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). The species is able to tolerate some degree of habitat conversion and is also found in small forest patches (CSS Brazil and CEMAVE-ICMBio 2020). Therefore, any population declines are unlikely to be rapid. Tentatively, population declines are here placed in the band 1-9% over ten years, but an exact quantification is urgently required.
Formicivora iheringi is known several disjunct sites in eastern Bahia and in Minas Gerais, east Brazil.
It inhabits the understorey and mid-storey of tropical deciduous and semi-deciduous forest at 250-1,060 m (del Hoyo et al. 2003, Zimmer and Isler 2020). In parts of the range it apparently favouring mata-de-cipó interiors with vine-tangles, a relatively open understorey and patches of terrestrial bromeliads (Zimmer and Isler 2020). It appears to show some tolerance of habitat degradation and disturbance and is also found in relatively small patches of forest remnants (CSS Brazil and CEMAVE-ICMBio 2020). It forages for invertebrates singly or in pairs, sometimes with flocks, generally up to 12 m above the ground (Ridgely and Tudor 1994, Zimmer and Isler 2020).
Its habitats are being cleared for cattle pasture in central-south Bahia, and much of the forest in north-east Minas Gerais and adjacent south Bahia has been cleared for coffee plantations. At Aracuai, tourmaline miners have disturbed all caatinga vegetation (Neto et al. 2001). Natural habitats are reduced to hilltops around Boa Nova (Whitney 1996), and remaining forest patches are highly disturbed by livestock and subject to local exploitation of trees for firewood and fenceposts (Tobias et al. 1993). However, the species seems to be able to cope with forest fragmentation, persisting in small areas.
Conservation Actions Underway
It is included in a multi-species action plan for birds in the Caatinga (ICMBio 2019).
11.5 cm. Long-tailed, arboreal antwren. Male slate-grey. Black wings, with two white wing-bars and white spotting on shoulder. Narrow white tips to outer rectrices. Grey underparts, with black bib extending to mid-breast. Silvery-white flanks. Female olive-brown above and more rufescent on uppertail-coverts. Dusky wings and tail, with two indistinct, buff wing-bars. Ochraceous underparts, palest on throat with limited white on flanks. Similar spp. White-flanked Antwren Myrmotherula axillaris luctuosa is shorter tailed and female has less rufescent uppertail-coverts and less uniform ochre underparts. Apparently not sympatric. Voice Male song is musical series of 7-12 (2 per second) metallic píeep notes. Female gives shorter, softer version.
Text account compilers
Hermes, C.
Contributors
Brammer, F., Butchart, S., Gilroy, J., Lima, D.M., Minns, J., Oniki, Y., Parrini, R., Phalan, B., Sharpe, C.J., Subirá, R., Whitney, B. & Willis, E.O.
Recommended citation
BirdLife International (2024) Species factsheet: Narrow-billed Antwren Formicivora iheringi. Downloaded from
https://datazone.birdlife.org/species/factsheet/narrow-billed-antwren-formicivora-iheringi 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.