Justification of Red List category
This species is restricted to very small, scattered areas of grasslands in alluvial plains. Connectivity between occupied areas is low, and it is assumed that the majority are in subpopulations that are both small and isolated. Ongoing loss and degradation of its habitat indicate that the population is in decline. The species is therefore listed as Vulnerable.
Population justification
The species inhabits small patches of habitat, where it is described as rare to uncommon or common (ICMBio 2018, L. Klemann Jr. in litt. 2020). Surveys at Banhado do Maçarico, Rio Grande do Sul, found a density of about 0.5 individuals per hectare, which led to an estimate of 200 breeding pairs at this site (G.N. Mauricio in litt. 2012). In Paraná and Santa Catarina, a density of 3.8 individuals per hectare was recorded (Klemann Jr. and Vieira 2013). Based on these densities, the global population was estimated at 16,800 individuals (L. Klemann Jr. in litt. 2020). This equates to 11,200 mature individuals.
Trend justification
The species is known to have disappeared from degraded and converted areas and to have declined in zones affected by fires (M.R. Bornschein in litt. 2022, G.N. Mauricio in litt. 2022). Pressures on its habitat via land-use change, draining of wetlands and increased frequency of fire continue to negatively affect the population (G.N. Mauricio in litt. 2022).
The construction of a dam in 2001, which flooded parts of the type locality in Iraí, led to drastic population declines; however it has been suggested that the species might be able to recolonise the area (L. Klemann Jr. in litt. 2020). Nevertheless, due to the ongoing threat of habitat degradation and loss, the population is assessed as being in continuing decline.
Scytalopus iraiensis was discovered in 1997, and is now known from a number of disjunct localities in Minas Gerais, Paraná, Santa Catarina and Rio Grande do Sul in south-eastern Brazil (Vasconcelos et al. 2008, Mlíkovský 2009, Klemann Jr. and Vieira 2013). It may also occur in São Paulo state, even though surveys have so far been unsuccessful (Vasconcelos et al. 2008, eBird 2022). The species occupies small patches of habitat that are highly fragmented. The species' strongholds and presumably the largest subpopulations are located in Banhado dos Pachecos and Banhado do Maçarico, as well as in Campos de Cima da Serra along the border of Santa Catarina and Rio Grande do Sul, where 'dozens of individuals' were recorded (ICMBio 2018).
It occurs in tall, dense grasslands (60-180 cm tall) in the alluvial plains of watercourses, generally flanked by gallery forest. In the coastal plain of southernmost Brazil it is also present in peat swamp habitat. These grasslands are seasonally inundated and dominated by Eleocharis sp. and several other Cyperaceae and Poaceae. The species inhabits the dense vegetation nearest to the ground, and climbs up and down stems and bushes. It is territorial; surveys in Paraná and Santa Catarina found territory sizes of around 0.5 ha (Klemann Jr. and Vieira 2013). Stomach contents included small arthropods and insects. It breeds during the late austral spring and possibly also in the summer.
The main threats to the species are the loss and degradation of its habitat due to ongoing land-use change, mainly through urbanisation, development, agriculture and road-building. Suitable grasslands are being systematically drained owing to canalisation schemes for improved agricultural land and pasture. Subsurface sand extraction and the planting of Eucalyptus trees have altered the landscape and vegetation in several areas. The use of widespread burning is common practice on these lands, which changes the floral composition and promotes the spread of invasive species, which in turn increases fire risk; the species is declining at sites affected by fires (M.R. Bornschein in litt. 2022, G.N. Mauricio in litt. 2022). The Iraí dam has partly flooded the type-locality.
Conservation Actions Underway
The species occurs in several protected areas across its range, including Serra do Cipó, Serra da Canastra and Aparados da Serra national parks, and Banhado Maçarico, Aves Gerais, Estadual do Rio Iraí, Estadual do Rio Pequeno and Banhado dos Pachecos reserves, and further protected areas (Vasconcelos et al. 2008, Klemann Jr. and Vieira 2013, ICMBio 2018, L. Klemann Jr. in litt. 2020). An Action Plan was derived in 2013 (ICMBio 2013). There were two legal interventions regarding the Iraí dam; first, to postpone plans for the dam and counter irregularities in the environmental impact assessment and, second (following the discovery of this species), to abandon the construction of the dam or create a conservation unit. However, neither intervention was successful, and the dam has been constructed.Conservation Actions Proposed
Survey suitable habitat in São Paulo and Santa Catarina to locate additional populations. Conduct detailed studies of the species' ecology, including on reproduction, dispersal abilities and genetic structure. Assess the species' tolerance of degraded habitats. Monitor the population trend.
Create further conservation units to protect the species. Protect suitable habitat to prevent infrastructural developments. Abandon the planned construction of dams that would flood areas where this species occurs. Cease drainage, fires and all sand extraction operations in such areas. Effectively manage protected areas where the species occurs. Restore degraded grasslands and wetlands to increase habitat availability.
12.5 cm. Plain, blackish tapaculo. Mainly blackish above with dark ashy underparts. Very faint barring on belly, possibly only in subadult birds. Rather large tail. Similar spp. Mouse-coloured Tapaculo S. speluncae is more concolourous. Voice Song is long series of tchek notes introduced by longer, more modulated notes. Calls pic-pic in alarm.
Text account compilers
Hermes, C.
Contributors
Allinson, T, Bornschein, M.R., Klemann Jr., L., Lima, D.M., Mauricio, G., Pioli, D., Pople, R., Reinert, B.L., Sharpe, C.J., Silveira, L.F., Subirá, R. & Symes, A.
Recommended citation
BirdLife International (2024) Species factsheet: Marsh Tapaculo Scytalopus iraiensis. Downloaded from
https://datazone.birdlife.org/species/factsheet/marsh-tapaculo-scytalopus-iraiensis 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.