NT
Bananal Antbird Cercomacra ferdinandi



Justification

Justification of Red List Category
This species is suspected to have undergone a moderately large population reduction over the last decade, which is suspected to continue over the next decade as a result of hydroelectricity development and consequent habitat loss and degradation. However, the past and future population reductions are not thought to be large enough to meet the thresholds for Vulnerable under Criterion A. For these reasons, the species is listed as Near Threatened.

Population justification
Although restricted in range and extent of habitat, it is common where it occurs. A study of ten territories at RPPN Canguçu in Tocantins found an average territory density of 0.31 per ha (31 per km2), ranging from 0.14 to 0.64 ha (Crozariol 2011). Based on these densities, a population of 220,000 pairs was estimated for Cantão State Park (Crozariol 2011). Studies at the Murici and Preto rivers, tributaries of the Araguaia, in the north of Tocantins, detected at least 22 individuals in a 1 km transect in floodplain vegetation (Dornas and Pinheiro 2018).

Based on knowledge of the species's distribution and population densities, the population size has been estimated at 15,000 - 20,000 mature individuals (T. Dornas in litt. 2020). Based on the recorded population densities, the area of tree cover with 50% canopy cover within within the species's mapped range (estimated at 46,600 km2; Global Forest Watch 2020), and assuming 10-25% of the forest is occupied, the population is estimated at 195,720-489,300 individuals, roughly equating to 130,480 - 326,200 mature individuals. Based on these estimates, the population size is here placed in the band 15,000 - 350,000 mature individuals.

There are no large gaps between areas with records and the species is considered to have a relatively high dispersal ability (Borges et al. 2019), so it is assumed to have one subpopulation.

Trend justification
The Estreito Hydro-Power Complex was recently constructed in the Tocantins-Araguaia river basin and within the species's range (T. Dornas in litt. 2020), going into operation in 2011. Remote-sensed data on tree cover indicated a loss of 16% of tree cover with 50% canopy cover within the mapped range over 10 years from 2010-2019 (Global Forest Watch 2020). From this information, the species is inferred to be undergoing a continuing decline in population size. An analysis of the impact of disturbance on forest species in Pará found that in private lands or sustainable-use reserves, the impact of disturbance on biodiversity was equivalent to that of an additional 51% loss of forest (Barlow et al. 2016). However, this species is known to be tolerant of disturbed habitats, and it occurs in flooded forest, which is likely to be subject to lower levels of deforestation than terra firma forest. Therefore, a population reduction of 10-24% is suspected to have occurred over the last ten years.

Further hydroelectric projects underway and planned for the lower Araguaia and middle Tocantins are expected to cause the loss of habitat in about 50% of its geographical distribution (D. Lima in litt. 2020). The species is dependent on habitats generated by the cycle of flooding and ebbing of the rivers, and its population was projected to decline by nearly 30% over 20 years from 2018 (D. Lima in litt. 2020). This equates to a decline of up to 16% over ten years. However, plans for further hydroelectricity plants are currently on hold and they are not expected to be constructed within the next 5-10 years (T. Dornas in litt. 2020).

If the average 2017-2019 rate of tree cover loss were to continue over ten years, this would equate to a loss of 25% of forest within the species's range. Adding the potential impact of disturbance, the population size could be suspected to undergo a reduction of up to 37%. However, given that the average rate of forest loss over the past decade was slower than this, and the main threat of hydroelectricity development is projected to cause of reduction of up to 16%, the population reduction over the next ten years is suspected to be smaller than the 2017-2019 deforestation rate may suggest. Overall, a population reduction of 10-29% is suspected over the next ten years.

Distribution and population

Cercomacra ferdinandi is endemic to the Araguaia-Tocantins basin, Brazil, occurring in Pará and Maranhão, through Tocantins and south to Mato Grosso and south to Goiás (Olmos et al. 2006, Vasconcelos and de Souza Werneck 2008, Kirwan et al. 2015, Crozariol 2016, WikiAves 2018). It occurs along the banks and tributaries of the Araguaia river from the Ilha do Bananal to the confluence with the river Tocantins, and along the banks and tributaries of the Tocantins river south to Palmeirante (Olmos et al. 2006, Vasconcelos and de Souza Werneck 2008). Its potential range appears to be larger than its currently known distribution since a species distribution model predicted several suitable regions of habitat in the north-northeastern, southeastern, and especially western parts of its distribution (Marini et al. 2010).

Ecology

This species is found in dense vine tangles in riparian thickets and forest undergrowth near water (frequently in seasonally flooded areas and oxbow lakes). It is dependent on habitats generated by the cycle of flooding and ebbing of the rivers (D. Lima in litt. 2020). Feeds individually, in pairs, or in small family groups on a variety of invertebrate prey (Olmos et al. 2006). Forages in thick vegetation but occasionally pursues flushed prey in flight (del Hoyo et al. 2003). Breeds from May to July (Crozariol 2011).

Threats

Its specialised habitat requirements make the species susceptible to changes in hydrological management. The greatest threat to the species is the development of hydroelectrocity projects (HPP), which are likely to flood large parts of the species's habitat (Brasil Choueri et al. 2017, Dornas and Pinheira 2018, D. Lima in litt. 2020). The Estreito Hydro-Power Complex was recently constructed in the Tocantins-Araguaia river basin and within the species's range (T. Dornas in litt. 2020), going into operation in 2012. The reservoir of this project reaches between Estreito (Maranhão) and Palmeirante (Tocantins; Dornas and Pinheiro 2018). Two hydroelectrical plants projects are currently in progress within the species's range: HPP Marabá (Pará) and HPP Santa Isabel (Tocantins). HPP Marabá is projected to produce a reservoir that will reach the dam of HPP Santa Isabel on the Araguai River, and HPP Serra Quebrada in Itaguatins (PAC 2018). HPP Santa Isabel is planned for the region of the Rapids of Santa Isabel, and the reservoir is projected to reach Araguanã (Dornas and Pinheiro 2018). There are plans to construct two further hydroelectrical plants (HPP) within the species's range by 2025: HPP Araguanã and HPP Serra Quebrada, both in Tocantins, but the plans are currently on hold and they are not expected to be constructed within the next 5-10 years (T. Dornas in litt. 2020). HPP Araguanã is projected to create a reservoir that will come close to Araguacema, and HPP Serra Quebrada will dam  the Tocantins river, with a reservoir reaching HPP Estreito (Dornas and Pinheiro 2018). If all the planned hydroelectricity projects are executed, they may alter almost 500 km of river for each of the two major rivers affected (D. Lima in litt. 2020).

Habitat loss is ongoing within the species's range, especially due to clearance for agriculture. Rates of deforestation in Brazil have increased from 2018-2019 (INPE 2019).

A climate vulnerability analysis projected that climatic conditions across the species's entire range will exceed those currently experienced by the species by 2015 (Borges et al. 2019).

Conservation actions

Conservation Actions Underway
It is included in the National Action Plan for the Conservation of the Birds of the Cerrado and the Pantanal (ICMBio 2019). It occurs in the Araguaia National Park, the Cantão State Park, the Ilha do Bananal/Cantão Environmental Protection Area and the Meandros do Rio Araguaia Environmental Protection Area (Dornas and Pinheiro 2018). The National Action Plan includes objectives to monitor the species and the rate of habitat loss, to identify ecological corridors for the species and to study the effects of hydroelectricity developments and other developments (ICMBio 2019). Studies have been carried out on the species's breeding densities and demography (Crozariol 2011).

Conservation and Research Actions Proposed
Undertake surveys to establish range and population size. Monitor habitat trends. Carry out further research into threats to the species, including the impacts of hydropower developments and climate change.
Pass legislation to limit developments along rivers. Lobby the government to revise plans for hydroelectric plants and control forest conversion. Enforce protected areas and protect habitat outside protected areas, particularly within ecological corridors.

Identification

16 cm. Medium-sized, dark antbird. Male jet black, with partially concealed white patch on back, white wing bars, white patch on bend of wing and broad white tail tips. Female largely grey with fine white streaking on throat and breast. Similar spp. No other similar antbirds within its restricted range. Voice A rapid and variable mammal-like chattery churring.

Acknowledgements

Text account compilers
Wheatley, H.

Contributors
Benstead, P., Dornas, T., Lima, D., Olmos, F., Sharpe, C.J. & Symes, A.


Recommended citation
BirdLife International (2022) Species factsheet: Cercomacra ferdinandi. Downloaded from http://www.birdlife.org on 03/10/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 03/10/2022.