Data Zone
Justification of Red List category
There have been been few recent sightings of this species, which must now have an extremely small population. All recent sightings have been made in and around the Mata do Passarinho Reserve on the Minas Gerais - Bahia border, so the species has an extremely small extent of occurrence. Its population size and habitat are likely to be declining owing to fires, logging and the clearance of steep humid valley-floor forest for cattle-ranching and agriculture. For these reasons it is classified as Critically Endangered.
Population justification
There have been very few recent records of the species. In the Jequitinhonha valley (the sole currently known population), at least four birds were found in a 100 ha area in the early 2000s, but it was thought unlikely that this density could be extrapolated for the whole 2,000 ha partly fragmented patch of forest (R. Ribon in litt. 2006, 2020). Subsequent surveys in the RPPN Mata do Passarinho and mata do Lodo found six individuals: five females and a single male (Damasceno 2011). Three males were recorded in 2012 (WikiAves 2013) and in 2011 the total population was considered to be no more than 10-15 individuals (R. Ribon in litt. 2011). Surveys in 2016 found only one pair with a nest, which failed, and surveys in 2017 did not detect any individuals (Rutter 2018). An expedition in 2018 found a single female outside the boundaries of the Reserva Mata do Passarinho (BirdGuides 2018). It is therefore now considered probable that there are no more than 10 individuals remaining (A. Souza in litt. 2020), and the population size is placed in the band 1-49 mature individuals.
Trend justification
There are no direct data on population trends. The species's population size is inferred to be in decline based on ongoing habitat degradation caused by fires and logging. According to Global Forest Watch, approximately 8.5% of tree cover with at least 50% canopy cover was lost within the species's mapped extant range over three generations (11 years) from 2008-2019 (Global Forest Watch 2020). This loss largely occurred in 2016 (Global Forest Watch 2020), when a large fire is known to have occurred (R. Ribon in litt. 2020). The species's population is therefore suspected to have declined by up to 10% over the past ten years.
Merulaxis stresemanni was known until relatively recently from just two specimens, the type, collected near Salvador in the 1830s, and a second taken near Ilhéus in 1945, in coastal Bahia, Brazil. In 1995, it was rediscovered in the wild when a male was observed and tape-recorded at Fazenda Jueirana, near Una Biological Reserve, Bahia (Baudet 2001). Subsequent searches there failed to produce further records (Baudet 2001, F. Olmos in litt. 2003), and most of the forest at the site has subsequently been cleared (A. Zaidan, pers. obs. 2018, in R. Ribon in litt. 2020). However, the species was subsequently found in the Jequitinhonha valley, Minas Gerais, near the border with Bahia (Ribon et al. 2004). All recent sightings, of which there have been few, have been made in and around the RPPN Mata do Passarinho on the Minas Gerais - Bahia border, including in the adjacent mata do Lodo (Damasceno 2011). In 2016, intense searches were carried out in and around RPPN Mata do Passarinho, and other forest fragments in the south of Bahia state, Biological Reserva of Una, Serra das Lontras National Park, and Chapada Diamantina National Park, but no other populations were found (A. Souza in litt. 2020).
The species is found in the understorey of the edges and interior of mature humid forest, often comprised of Cecropia spp., at 600-930 metres along the Jequitinonha and Pardo River valleys (R. Ribon in litt 2007, Damasceno 2011). Its behaviour and habitat preferences appear similar to those of M. ater (Baudet 2001). The male in 1995 was observed foraging on the ground and on fallen tree trunks in an area of drier forest between two humid valleys (Baudet 2001). The species has been observed apparently feeding on arthropods on dry litter and under fallen logs (Fundação Biodiversitas in litt. 2010, R. Ribon in litt. 2020). Birds are very responsive to play-back, approaching the observer to 2 m (R. Ribon in litt 2007), and move mainly by walking or short-distance flights (Damasceno 2011). The average territory size of three birds was 2.36 ha, based on initial studies, but more data are required (Fundação Biodiversitas in litt. 2010). The first known nest site was found in 2012, and consisted of a tennis-ball sized hole c.3 feet above the ground in an exposed dirt bank with overhanging vegetation, with a nesting tunnel estimated to be c.6 feet deep (ABC 2013).
Most humid forest in Bahia has been cleared or converted to cacao plantations, and remaining patches are disappearing very rapidly. Forest in the Minas Gerais and Bahia border area is being cleared for small (mostly in Jordânia county, Minas Gerais) and large scale cattle ranching and for eucalyptus plantations (R. Ribon in litt. 2007, Piacentini et al. 2018). Forest is also degraded by loggers (R. Ribon in litt. 2007, Damasceno 2011). Intentional or accidental fires are set every year, degrading the border of the remaining pristine forest and sometimes escaping into the reserve (R. Ribon in litt. 2007, Rutter 2018). A fire in 2016 burned the site of the only known breeding pair, and no individuals have since been recorded at the site (R. Ribon in litt. 2020). A drought from 2010 onwards may have degraded the habitat for the species and increased the risk of fire (Rutter 2018). Predation by feral cats and dogs may also be a threat (Piacentini et al. 2018).
Conservation Actions Underway
It is considered Critically Endangered at the national level in Brazil (MMA 2014), and protected by Brazilian law. The species is included in the National Action Plan for the Conservation of the Birds of the Atlantic Forest (ICMBio 2017).
The sighting in 1995 was in a privately-owned fazenda (Fazenda Jueirana) adjacent to the 5,400 ha Una Biological Reserve. The 400 ha Mata da Balbina in Jequitinhonha valley, Bandeira and Macarani municipalities, where the species was discovered in 2005, was purchased by the Fundação Biodiversitas, a local NGO from Minas Gerais, and is managed as RPPN Mata do Passarinho, a Private Natural Heritage Reserve (P. Develey in litt. 2007, Anon 2008, Whitehouse and Ribon 2010). A further 194 ha section of forest was purchased in March 2009, along with infrastructure improvement and the hiring of a reserve manager (American Bird Conservancy 2009, SAVE Brasil in litt. 2010). In 2016, the reserve was further expanded to a total size of 9.5km2 (Rutter 2018).
Artificial nest sites have been created and their use is being monitored, but their success is yet to be verified (Piacentini et al. 2018). A visitor centre has been created at RPPN Mata do Passarinho, and groups of pupils from local schools have visited (Biodiversitas 2015). Under a project that ran until 2015, an education programme raised awareness about the biodiversity of the reserve among local communities (Biodiversitas 2015). This involved the training of local teachers and the production of educational materials for use in local schools. Also as part of the project, forest restoration took place within the reserve (Biodiversitas 2015). Lodges have been built to encourage tourism by birdwatchers (Biodiversitas 2015).
Surveys are being carried out to monitor the population size of the species (Fundação Biodiversitas in litt. 2010, SAVE Brasil in litt. 2010). In 2016, intense searches were carried out in and around RPPN Mata do Passarinho, and other forest fragments in the south of Bahia state, Biological Reserva of Una, Serra das Lontras National Park, and Chapada Diamantina National Park, but no other populations were found (A. Souza in litt. 2020). Surveys carried out in 2018 by the American Bird Conservancy (ABC) and Fundação Biodiversitas, funded by the Global Environment Facility (GEF) as part of the Alliance for Zero Extinction (AZE), found a single female outside the boundaries of the Reserva Mata do Passarinho (BirdGuides 2018).
Conservation Actions Proposed
Carry out further surveys in Jequitinhonha and Bandeira to monitor the size and status of the population. Search for additional populations in fragments of humid forests in Bahia and northeastern Minas Gerais, using playback, and determine the size and status of the remaining population.
Create further protected areas and safeguard the remaining unprotected 3,400 hectares of forest in the Jequitinhonha valley, and remaining tracts of humid forest in Bahia. Create corridors to connect small tracts of pristine forest currently disconnected from the largest tract on the Bandeira-Jordânia-Macarani border. Improve enforcement to prevent fires and logging from damaging the species's habitat. Regulate use of playback on tiny known population, whilst maintaining potential for ecotourism. Investigate the possibility of managing the remaining population in semicaptivity, with supplementary feeding (Piacentini et al. 2018), or of initiating a captive breeding programme (A. Souza in litt. 2020).
20 cm. Medium-sized, long-tailed bird with distinctive forehead bristles. Male all slaty-plumbeous. Dark rufous-chestnut rump, uppertail-coverts and vent, although rump and uppertail coverts appear more greyish than vent, which is more rufescent. Long, pointed bristles on forehead. Slender dark bill. Female is cinnamon-brown above, with duskier tail. Bright cinnamon-rufous below. Similar spp. Very similar to Slaty Bristlefront M. ater but no known overlap in range. (one specimen of M. ater purported to be obtained Bahia by Helmut Sick is probably M. stresemanni) Voice Very different from M. ater. Characteristic falling series of musical whistled notes, slightly ascending in the end, of 10-12 seconds duration. Also semi-musical tink call.
Text account compilers
Wheatley, H.
Contributors
Develey, P., Olmos, F., Ribon, R., Souza, A. Z., Symes, A., Pople, R., Mahood, S., Hermes, C., Calvert, R., Bird, J., Capper, D., Butchart, S., Clay, R.P., Sharpe, C.J. & Taylor, J.
Recommended citation
BirdLife International (2024) Species factsheet: Stresemann's Bristlefront Merulaxis stresemanni. Downloaded from
https://datazone.birdlife.org/species/factsheet/stresemanns-bristlefront-merulaxis-stresemanni 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.