Justification of Red List category
This species has a very small and severely fragmented range and population, with records from few locations (Collar et al. 1992). Remaining habitat is declining rapidly, principally for conversion to cattle pasture. It consequently qualifies as Endangered.
Population justification
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. However, censuses in forest fragments in Boa Nova revealed an average density of 0.9 individuals / hectare and suggests that the populations exceeds 2500 birds (E. Luiz in litt. 2012, Luiz et al. 2015, Zimmer et al. 2015).
Trend justification
A rapid and ongoing population decline is suspected owing to rates of habitat loss.
Rhopornis ardesiacus occupies a small range in east Bahia (from Brejões south to Potiraguá [E. Luiz in litt. 2012]) and north-east Minas Gerais (Fazenda Santana, near Salto da Divisa [Ribon and Maldonado-Coelho 2001]), Brazil. Although it can be locally common, it is very rare and presumably declining owing to the rapid loss and fragmentation of its restricted habitat.
It inhabits dry forest (mata-de-cipó) between 100-900 m, in areas characterised by a fairly open understorey with an abundance of lianas and patches of the huge terrestrial bromeliads of the genera Aechmea and Ananas. Pairs seem to have small home ranges (possibly as little as 50 m across, with estimates of 0.9 to 2 ha at Boa Nova [E. Luiz in litt. 2007]), but as suitable bromeliad patches are seldom close together, territories are usually separated by 100 m or more. The birds feed on the ground, on low branches and in the bromeliads, where they toss leaves searching for invertebrate prey, principally small termites but also including grasshoppers, crickets, cockroaches and spiders. They have also been observed following army ant swarms. Breeding occurs primarily in October-December. A nest was found resting on a bromeliad leaf at ground level in a patch of terrestrial bromeliads in November (Luiz 2008).
Dry forest in east Bahia has been reduced to scattered fragments by rapid and continuing clearance for cattle pasture as well as clearance for firewood by local communities. Cattle and goats trample seedlings and prevent forest regrowth, and in some areas bromeliads are harvested for sale (E. Luiz in litt. 2007). Fragments totalled about 965 km2 in the early 1970s and, by 1990, 5-20% (nearer 5%) of primary dry forest was estimated to remain in this part of Bahia. However, much of what remains is apparently unsuitable for the species since many woodlots are highly disturbed by livestock. Furthermore, it has not been found in several areas of relatively pristine habitat.
Conservation Actions Underway
Considered Endangered at the national level in Brazil (Silveira & Straube 2008, MMA 2014), and protected under Brazilian law. A conservation project began in 2004 at Boa Nova aiming to involve the local community with focus on research into the species' ecology, environmental education and awareness campaigns and implementing sustainable land-use practices (E. Luiz in litt. 2007). In 2010 a 10,000 ha national park and a 17,000 ha wildlife refuge were created at Boa Nova (E. Luiz in litt. 2012).
19 cm. Large, grey antbird with red iris. Male ashy-grey above, paler below. Black, triangular throat patch. Long blackish tail and wings with fine white wing-bars. Long blackish bill. Female resembles male but duller. Rufous-brown forehead, crown and hindneck. Paler underparts. Whitish throat. Brownish iris. Voice Song is series of six or seven high-pitched and sharp kíu notes, of c.3 seconds duration. Sharp and metallic tchíek calls.
Text account compilers
Capper, D., Clay, R., Pople, R., Sharpe, C J, Symes, A., Williams, R.
Contributors
Luiz, É., Whittaker, A.
Recommended citation
BirdLife International (2024) Species factsheet: Slender Antbird Rhopornis ardesiacus. Downloaded from
https://datazone.birdlife.org/species/factsheet/slender-antbird-rhopornis-ardesiacus on 24/12/2024.
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 24/12/2024.