Justification of Red List category
This species has a small area of occupancy and is inferred to be declining as a result of ongoing deforestation. Its habitat is very fragmented and the population is likely to be severely fragmented. For these reasons, the species is listed as Vulnerable.
Population justification
It is generally considered uncommon and local, and appears to be common at very few sites. A study in the Rio Doce State Park found that it was 69% less abundant in an area of secondary forest than in an area of primary forest (Loures-Ribeiro et al. 2011).
Based on a modelled population density of approximately 7.6 individuals per square kilometre (Santini et al. 2019) and the estimated remaining tree cover with at least 50% canopy cover in the known range in 2020 (c.2000 km2; Global Forest Watch 2021), the maximum population size in the known range is inferred to be 15,200 individuals, roughly equivalent to 10,100 mature individuals. The species has specific micro-habitat requirements (D. Lima in litt. 2020), so it is unlikely to occupy all available forest. However, it has been recorded at several further localities in recent years (WikiAves 2018) and so there may be further small undiscovered populations. The population size is therefore placed in the band 2,500 - 15,000 mature individuals.
The number of subpopulations is not known, but the remaining primary forest within the species's range is highly fragmented, so there are assumed to be 11-20 subpopulations based on a visual assessment of the known range. The largest remaining forest fragment with recent records is Sooretama, with approximately 60 km2 of tree cover (Global Forest Watch 2021). Based on the above density estimate, the largest subpopulation is estimated to have less than 1,000 mature individuals.
Trend justification
The species is reported to have become less common in the Sooretama Biological Reserve (D. Lima in litt. 2020). Remote-sensed data on tree cover loss indicates that over ten years from 2010 to 2020, approximately 9% of tree cover with at least 50% canopy cover was lost within the species's extant and possibly extinct range (Global Forest Watch 2021). The rate of tree cover loss within the species's known extant range was lower, with approximately 3% lost over 2010-2020 (Global Forest Watch 2021). The species prefers undisturbed forest and is therefore inferred to be declining, and to have undergone a reduction of 1-9% over the past ten years. Based on the average rate of forest loss over the past five years, approximately 10% of tree cover is suspected to be lost within the species's extant and possibly extinct range over the next ten years. The species's population is therefore suspected to undergo a reduction of up to 10% over the next ten years.
Dysithamnus plumbeus occurs in south-east Brazil, from southern Bahia, through Espírito Santo and east Minas Gerais to extreme north-west Rio de Janeiro. In Bahia, most recent reports have come from Serra Bonita Private Reserve (Camacan; de Lima Silva et al. 2018, WikiAves 2018), and there have also been recent records from Jaguaquara, Jequié and Itapebi municipalities, Mata do Passarinho Reserve (Macarani) and Boa Nova National Park (WikiAves 2021; GBIF.org 2021). In Minas Gerais, there have been recent records from Bandeira, Tombos and Rio Casca municipalities, the Feliciano Miguel Abdala private reserve (Caratinga), and Rio Doce State Park (Marliéria/Timóteo) (Mazzoni et al. 2014; WikiAves 2021; GBIF.org 2021). In Espírito Santo, recent records have come from Domingos Martins and Guaçuí municipalities, Cafundó private reserve (Cachoeiro de Itapemirim), in and around REBIO de Duas Bocas (Cariacica), Sooretama Biological Reserve (Linhares/Sooretama; WikiAves 2021; GBIF.org 2021). In Rio de Janeiro state there are recent records from Porciúncula municipality (WikiAves 2021).
It inhabits the lower stratum of tall primary or little-disturbed, lowland Atlantic forest up to 900 m (Zimmer & Isler 2019). A study in the Rio Doce State Park found that it was 69% less abundant in an area of secondary forest than in an area of primary forest (Loures-Ribeiro et al. 2011). Pairs or singles generally forage within 2 m of the ground (occasionally to 4 m when associating with mixed-species flocks) in dense tangles, especially in shaded, old treefalls overgrown with vines and saplings. The diet consists of arthropods, including katydids, stick insects, pupas and insect eggs, gleaned from leaves and twigs. Territories appear to be fairly small (less than 1.5 ha) and fixed, with pairs exceptionally occurring within 75 m of each other. A nest with two eggs being incubated has been found in August.
The fragmentation of the species's range by extensive forest clearance has been and remains the one significant threat. Forest is lost through the removal of timber and firewood (de Lima Silva et al. 2018) and through conversion to agriculture, including arable crops and pastureland. Escaped agricultural fires also pose a threat.
Conservation Actions Underway
It is considered nationally Endangered in Brazil (MMA 2014, de Lima Silva et al. 2018) and is protected under Brazilian law. It is included in the National Action Plan for the Conservation of the Birds of the Atlantic Forest (ICMBio 2017). It has been recorded in several protected areas, including RPPN Serra Bonita, REBIO Augusto Ruschi, REBIO de Duas Bocas, REBIO de Sooretama, FLONA de Pacotuba and PE do Rio Doce (de Lima Silva et al. 2018).
Conservation Actions and Research Proposed
Survey known sites to ascertain its population size. Survey other forested areas within its range to clarify its current distribution. Map the species's occupied habitat to better estimate the area of occupancy. Monitor known populations. Monitor ongoing forest loss across the species's range.
Ensure the enforcement of protected areas where it does occur. Create new protected areas at sites where the species occurs. Protect remaining forest within its range and restore forest, particularly between remaining patches.
12.5 cm. Small, chunky, uniformly coloured antbird. Male slate-grey, blacker on chest, with white carpal bend and tips to coverts. Female dull olive-brown above, with buffy-white carpal and covert markings. Whitish throat. Ochraceous lower belly and vent. Similar spp. Myrmotherula antwrens are smaller. Cinereous Antshrike Thamnomanes caesius is larger, and lacks covert markings and black on chest. Voice 2-3 second series of c.10 melancholy, whistled notes, rising at start then fading.
Text account compilers
Wheatley, H.
Contributors
De Luca, A., Develey, P., Laps, R., Oniki, Y., Pacheco, J.F., Silveira, L.F., Whitney, B., Willis, E.O., Raby , R., Kirwan, G.M., Williams, R., Sharpe, C.J., Clay, R.P., Symes, A., Harding, M. & Mendes Lima, D.
Recommended citation
BirdLife International (2024) Species factsheet: Plumbeous Antvireo Dysithamnus plumbeus. Downloaded from
https://datazone.birdlife.org/species/factsheet/plumbeous-antvireo-dysithamnus-plumbeus 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.