Archived 2016 topics: The newly described taxon Scytalopus perijanus is to be recognised as a species by BirdLife: list as Near Threatened or Vulnerable?

This is part of a consultation on the Red List implications of extensive changes to BirdLife’s taxonomy for passerines

Lynx Edicions and BirdLife International will soon publish the second volume of the HBW-BirdLife Illustrated Checklist of the Birds of the World, building off the Handbook of the Birds of the World series, and BirdLife’s annually updated taxonomic checklist.

The new Checklist will be based on the application of criteria for recognising species limits described by Tobias et al. (2010). Full details of the specific scores and the basis of these for each new taxonomic revision will be provided in the Checklist.

Following publication, an open and transparent mechanism will be established to allow people to comment on the taxonomic revisions or suggest new ones, and provide new information of relevance in order to inform regular updates. We are also actively seeking input via a discussion topic here regarding some potential taxonomic revisions that currently lack sufficient information.

The new Checklist will form the taxonomic basis of BirdLife’s assessments of the status of the world’s birds for the IUCN Red List. The taxonomic changes that will appear in volume 2 of the checklist (for passerines) will begin to be incorporated into the 2016 Red List update, with the remainder to be incorporated into subsequent Red List updates.

Preliminary Red List assessments have been carried out for the newly split or lumped taxa. We are now requesting comments and feedback on these preliminary assessments.

The newly described taxon Scytalopus perijanus is to be recognised as a species by BirdLife following application of the Tobias et al. (2010) criteria, which support its distinctiveness from congeners.

S. perijanus, Perija Tapaculo, is found only in the Perija Mountains of north Colombia and Venezuela, in humid montane and elfin forest between 1,600 and 3,225 m, and possibly shrubby areas near forest patches and plantations (Avendaño et al. 2015). Specimens of this species were first collected in 1941, but were assigned to different taxa (see Avendaño et al. 2015). However, the recent collection of additional specimens have shown, together with vocal and genetic analyses, that this is a separate taxon (Avendaño et al. 2015).

While lower-elevation habitat (below 2,000 m) is under threat from a range of processes (including colonisation, ranching, the cultivation of narcotics, and mineral exploitation – which are aided by the roads approaching the Colombian side – [C. J. Sharpe in litt. 1997, 2000, A. Viloria per J. Fjeldså in litt. 1998, Sharpe and Lentino 2008]), it was thought high-elevation habitat would be less affected by these factors. However, such areas are now believed to be being affected by illegal cultivation, causing habitat declines fragmentation (Renjifo et al. 2002, C. J. Sharpe in litt. 2003).

The degree to which this species may tolerate anthropogenic disturbance is not certain, but the species has been predicted to be ‘fairly common’ in both primary and tall secondary forest that may be subject to logging, as well as in shrubby areas near forest or plantation patches (Avandaño et al. 2015). However, it is intolerant of areas of complete habitat removal which may have been transformed into paramo tussock grassland (Avandaño et al. 2015), which may now cover c.37% of the upper montane region in this mountain range, possibly aided by fires and the abandonment of cultivated land (Arellano-P. and Rangel-Ch. 2007, Avandaño et al. 2015). Not all of this conversion may have occurred within the last 10 years, but it is suspected that this species may have undergone at least a moderate decline over the past 10 years (in the range of 20-29% decline), which is likely to continue. This would then qualify the species to be listed as Near Threatened under criteria A2c+3c+4c, but we welcome any further comments as to the rate of decline of this species to see whether it merits listing as Vulnerable under the same criteria. Also, while we recognise that this species’s habitat is fragmented, we welcome any evidence or comments to suggest whether it is severely fragmented (see IUCN 2001, 2012), as then the species would likely qualify at least as Vulnerable under criterion B1ab(i,ii,iii,v).

References:

Arellano-P., H., and J. O. Rangel-Ch. (2007). Caracterización ecológica, oferta ambiental, uso del suelo, transformación y zonificación ambiental. In Colombia Diversidad Biótica V: La Alta Montaña de la Serranía de Perijá (J. O. Rangel-Ch., Editor). Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá, Colombia. pp. 347–374.

Avendaño, J. E., Cuervo, A. M., López-O., J. P., Gutiérrez-Pinto, N., Cortés-Diago, A. and Cadena, C. D. 2015. A new species of tapaculo (Rhinocryptidae: Scytalopus) from the Serranía de Perijá of Colombia and Venezuela. Auk 132: 450-466.

IUCN. 2001. IUCN Red List Categories and Criteria: Version 3.1. Gland, Switzerland and Cambridge, UK: IUCN Species Survival Commission.

IUCN. 2012. Guidelines for Application of IUCN Red List Criteria at Regional and National Levels: Version 4.0. Gland, Switzerland and Cambridge, UK: IUCN.

Renjifo, L. M., Franco-Maya, A. M., Amaya-Espinel, J. D., Kattan, G. H. and López-Lanús, B. 2002. Libro rojo de aves de Colombia. Instituto de Investigación de Recursos Biológicos Alexander von Humboldt y Ministerio del Medio Ambiente, Bogotá, Colombia.

Sharpe, C.J. and Lentino, M. 2008. Piscuiz de Perijá Schizoeaca perijana. In: Rodríguez, J.P. and Rojas-Suárez, F. (eds), Libro Rojo de la fauna Venezolana. Tercera Edición, pp. 150. Provita & Shell Venezuela, S.A., Caracas, Venezuela.

Tobias, J. A., Seddon, N., Spottiswoode, C. N., Pilgrim, J. D., Fishpool, L. D. C. and Collar, N. J. 2010. Quantitative criteria for species delimitation. Ibis 152: 724–746.

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3 Responses to Archived 2016 topics: The newly described taxon Scytalopus perijanus is to be recognised as a species by BirdLife: list as Near Threatened or Vulnerable?

  1. Thomas Donegan says:

    Please see the comments on the Atlapetes nigrifrons thread for links to papers discussing details of the current conservation threats and situation in Perija.

  2. Scytalopus perijanus is relatively uncommon on Serrania del Perijae. The patchy secondary forest is very few also the not primary forest in the area. Its population density is likely <10,000 mature individuals, supporting Vulnerable under criterion C2a(ii)

  3. James Westrip (BirdLife) says:

    Based on available information, our preliminary proposal for the 2016 Red List would be to conservatively list this species as Vulnerable under criterion C2a(ii).

    There is now a period for further comments until the final deadline of 28 October, after which the recommended categorisations will be put forward to IUCN.

    Please note that we will then only post final recommended categorisations on forum discussions where these differ from the initial proposal.

    The final 2016 Red List categories will be published on the BirdLife and IUCN websites in early December, following further checking of information relevant to the assessments by both BirdLife and IUCN.

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