This discussion was first published as part of the 2022.2 Red List update. At the time a decision regarding its status was pended, but to enable potential reassessment of this species as part of the 2023 Red List update this post remains open and the date of posting has been updated.
Dear colleagues,
I think that the proposed NT category for Marsh Tapaculo is not supported by the available data. All populations are very probably isolated from each other by several man-made impacts such as roads, dams, cities and new rural developments. My long experience with this species indicates that it cannot disperse over habitats without tall / very dense marsh vegetation.
Additionally, we have found that the population from the Banhado do Maçarico have suffered a decline after great fires that have occurred there in the last decade. For example, no individual of Scytalopus iraiensis have been found in a 1 km transect where 10 birds were heard a few months before.
Best regards,
Giovanni
* Scytalopus iraiensis *
In the assessment of the risk of extinction of the Brazilian fauna carried out in 2019, the species was categorized as Endangered (EN) B2ab(ii,iii).
*Evaluators:* Luís Fábio Silveira; Caio Graco Machado Santos; Ciro Ginez Albano; Diego Mendes Lima; Glayson Ariel Bencke; Jose Fernando Pacheco; Victor de Queiroz Piacentini; Wagner Nogueira Alves.
*Criterion A* – In the assessment carried out in 2019, we did not find long-term data from population estimates to track the decline by observed data (a) and the decline of AOO and EOO (c) do not reach the thresholds for a threat category. Habitat loss calculations do not reach quantitative thresholds for three generations of the species.
*Criterion B* – The EOO calculations (313,614 km2) do not meet the thresholds for categorizing threatened. Its AOO (440 km2), calculated by superimposing a grid with 4 km2 squares to the points of current confirmed, inferred and suspected records.
It occurs in the states of Minas Gerais, Paraná, Santa Catarina and Rio Grande do Sul (Maurício et al., 2013); the first state was included in its known distribution only recently. Specific searches in the state of São Paulo did not result in records of the species, a fact that supports the hypothesis that the Minas Gerais population is isolated from those in the southern states (Vasconcelos et al., 2008). Its entire population is severely fragmented and isolated.
The population is severely fragmented with more than 50% of its area of occupation separated by great distances, with no gene flow. There is a continuous decline in the area of occupation and in the quality of the habitat due to the drainage of the wetlands due to the canalization systems for the development of agriculture and livestock (Straube et al., 2004; Maurício et al., 2013); construction of dams and weirs; urban sprawl (Reinert & Bornschein, 2008); underground sand extraction; fires (Krabbe & Schulenberg, 2003).
*criterion C* – There is no information available on population estimates.
Criterion D – There is no information available on population estimates.
Criterion E – in the evaluation carried out in 2017, we did not find PVA data.
Justification: Scytalopus iraiensis is endemic to Brazil, occurring in Minas Gerais, Paraná, Santa Catarina and Rio Grande do Sul. Inhabits swamps with tall and extremely dense grasses, covered with Eleocharis, other sedges and grasses. The population is severely fragmented, with an area of occupancy (AOO) calculated at 440 km², with more than 50% of its population separated by large distances, with no gene flow. There is a continuous decline in the area of occupation and in the quality of the habitat due to the drainage of the floodable areas due to the canalization systems for the development of agriculture and livestock, construction of dams and weirs, urban expansion, extraction of sand from the subsoil and fires. Therefore, S. iraiensis was categorized as Endangered (EN) by the B2ab(ii,iii) criterion.
References
Maurício, G.N.; Fontana, C.S. & Bornschein, M.R. Reinert, B.L., 2013. Scytalopus iraiensis. p.31–33. In:Serafini. Plano de
Ação Nacional para a Conservação dos Passeriformes Ameaçados dos Campos Sulinos e Espinilho, ICMBio, Instituto
Chico Mendes de Conservação da Biodiversidade Brasilia.
Vasconcelos, M.F.; Lopes, L.E.; Machado, C.G. & Rodrigues, M., 2008. As aves dos campos rupestres da Cadeia do
Espinhaço: diversidade, endemismo e conservação.. Megadiversidade, 4: p.197-217.
Straube, F.C.; Urben-Filho, A. & Kajiwara, D. 2004. Aves. p.143–496. In: Mikich & Bérnils. Livro Vermelho da Fauna
Ameaçada no Estado do Paraná. Mater Natura – Instituto de Estudos Ambientais. 764p.
Reinert, B.L. Bornschein, M.R., 2008. Scytalopus iraiensis Bornschein, Reinert & Pichorim, 1998. p.594–595. In:Machado
et al.. Livro Vermelho da Fauna Brasileira Ameaçada de Extinção, Ministério do Meio Ambiente e Fundação Biodiversitas
Brasilia, DF; Belo Horizonte, MG.
Krabbe, N.K. & Schulenberg, T.S. 2003. Family Rhinocryptidae. p.748–787. In:del Hoyo et al.. Handbook of the birds of
the world, Vol 8: Broadbills to Tapaculos. Lynx Edicions
If the species is restricted to swamp areas (“banhados”), the AOO calculated by the national assessment (440km²) may be more realistic than 9,000 km², and therefore, it fits as EN under B2.
Comments by Marcos R. Bornschein on the proposed downlisting of Scytalopus iraiensis from the list of endangered birds (translated from Portuguese by Ben Phalan).
Dear Colleagues,
The colleagues Giovanni Nachtigall Mauricio and Diego Mendes Lima have already made important contributions to reinforce the conservation status of S. iraiensis as a threatened species, with great propriety. I would like to contribute with some arguments based on: 1) weaknesses in conservation legislation, 2) cultural attitudes towards the wetland environments this species depends on, 3) large-scale alteration of plant communities, and 4) lack of data to justify downgrading this species to non-threatened.
(1) Brazilian legislation is geared to protect forests (Bornschein et al. 1998) and, since the time of description of S. iraiensis, has not advanced in the sense of guaranteeing protection to wetlands (such as floodplains). Often the environments where S. iraiensis occurs are swamps (floodplains) that occur beyond the banks of rivers lined with riparian forest. This riparian forest receives legal protection, but the wetlands do not. In this sense, (2) these wetlands are historically altered by drainage channels that cut through them carrying water quickly towards rivers, causing desiccation and opening up these areas to use for crops, grazing and human occupation. In many cases, numerous drainage channels are installed, but, for some reason, the foreseen uses are not implemented. In such conditions, S. iraiensis continues to occur for a period, but the flora starts to change and the vegetation dries up in winter, becoming much more susceptible to large fires. The use of the environments where S. iraiensis occurs are so ingrained in popular culture that a government programme was created in the state of Paraná to encourage irrigation and drainage of wetlands to increase agricultural production, known as “Pró-várzea” (the floodplain programme). Vast wetlands in the region where S. iraiensis occurs were decimated, as for example those in the municipalities of Castro and Piraí do Sul, east-central Paraná State. This programme no longer exists, but the culture of human use of the wetlands continues. Aided by the absence of legal protection and by new technologies, wetlands are now completely dried up and made to disappear for agricultural use with heavy machinery, including, for example, for the cultivation of soybeans and corn.
(3) Since 1998, the impact of the replacement of the original flora of wetlands inhabited by S. iraiensis by Typha domingensis (cattail), with the consequent disappearance of the bird, has been known. Wetlands that in 1998 (Bornschein et al. 1998) were beginning to be invaded by T. domingensis became completely dominated by this plant over a few years and many other intact wetlands at the time were invaded by T. domingensis and are much altered today. I do not know the dimension of this impact in other states where S. iraiensis occurs besides Paraná, but there is the potential for invasion by T. domingensis along the entire geographical distribution of the bird, since this plant is native in Brazil and widely distributed.
(4) Much of what is known about S. iraiensis is its geographical distribution and many points where it has been recorded. This is very positive, but may give a misleading view of the status of the species. An initial work of ours (Bornschein et al. 2001) pointed to numerous new records, but we did not address in the paper the number of localities investigated and discarded because of the destruction of wetlands, or discarded because no S. iraiensis were encountered there. The work of Klemann & Vieira (2013) can be interpreted to suggest that S. iraiensis should not be considered threatened, but other methodological approaches might give a very different picture, taking account of the large regions without records of the bird, as for example in the state of São Paulo.
Due to all of the above, I believe that it would be erroneous to downlist S. iraiensis.
References
Bornschein, M.R., Pichorim, M. & Reinert, B.L. 2001. New records of Scytalopus iraiensis. Nattereria 2: 29-33.
Bornschein, M.R., Reinert, B.L. & Pichorim, M. 1998. Description, ecology and conservation of a new Scytalopus (Rhinocryptidae) from southern Brazil, with comments on the morphology of the family. Ararajuba 6(1): 3-36.
Klemann Jr, L. & Vieira, J. S., 2013. Assessing the extent of occurrence, area of occupancy, territory size, and population size of marsh tapaculo (Scytalopus iraiensis). Animal Biodiversity and Conservation, 36(1): 47-57
Given the information presented by Giovanni, Diego and Marcos, I would suggest that it is premature to downlist this species, and suggest to pend a decision until this Brazilian endemic species can be revisited as part of the National Red List process, which will now provide annual updates.
In particular, reports of substantial declines in habitat area and quality are concerning. This species has a specialised wetland habitat that is greatly restricted in extent. These wetlands are, as Marcos points out, even more vulnerable to loss and degradation than other habitats because of weak legal protection, their high value as potential agricultural land, and a culture of drainage and land “improvement”. Shifts in plant community composition and increases in the frequency of large fires only multiply the threats facing this species. Furthermore, changes in habitat area and quality are more difficult to derive from existing landcover products than they would be for forest-dependent species.
Ben Phalan
Centre for Conservation of Atlantic Rainforest Birds
Instituto Claravis, Parque das Aves, Paraná, Brazil
Preliminary proposal
Based on available information, our proposal for the 2022.2 Red List is to pend the decision on this species and keep the discussion open until 2023, while leaving the current Red List category unchanged in the 2022.2 update.
There is now a period for further comments until the final deadline on 24 July 2022, after which the recommended categorisations will be put forward to IUCN. The final 2022.2 Red List categories will be published on the BirdLife and IUCN websites in December 2022, following further checking of information relevant to the assessments by both BirdLife and IUCN.
According to Giovanni Nachtigall and the national assessment, the population is severely fragmented and there is a decline in population, area of occupancy and habitat quality. I would suggest trying to calculate AOO and confirm the value found by CEMAVE/ICMBio and classify the species as EN or VU under B2ab(ii,iii).
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now temporarily closed and we are unable to accept any more comments until 6 February 2023. We will now analyse and interpret new information, and we will post a preliminary decision on this species’ Red List status on this page on 6 February 2023, when discussions will re-open.
Preliminary proposal
Following comments submitted on this discussion forum, the species’ range has been remapped and the AOO recalculated as 1,956 km2, which meets the numerical threshold for a listing as Vulnerable under Criterion B2. It is recognised that the population is severely fragmented and that there are continuing declines in AOO, habitat quality and population size. The species factsheet and proposed classification have been updated to reflect this information.
Based on available information, our preliminary proposal for the 2023 Red List would thus be to list Marsh Tapaculo as Vulnerable under Criterion B2ab(ii,iii,v).
There is now a period for further comments until the final deadline on 12 February 2023, after which the recommended categorisations will be put forward to IUCN.
The final 2023 Red List categories will be published on the BirdLife and IUCN websites in December 2023, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments. We will analyse and interpret available information, and we will post a final decision on this species’ Red List status on this page on 20 February 2023.
Recommended categorisation to be put forward to IUCN
The final categorisation for this species has not changed. Marsh Tapaculos is recommended to be listed as Vulnerable under Criterion B2ab(ii,iii,v).
Many thanks for everyone who contributed to the 2023.1 GTB Forum process. The final 2023 Red List categories will be published on the BirdLife and IUCN websites in December 2023, following further checking of information relevant to the assessments by both BirdLife and IUCN.