Archived 2016 topics: Long-tailed Woodcreeper (Deconychura longicauda) is being split: list D. longicauda and D. typica as Least Concern and D. pallida as Near Threatened?

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.

Long-tailed Woodcreeper Deconychura longicauda is being split into D. longicauda, D. typica and D. pallida, following the application of criteria set out by Tobias et al. (2010).

Prior to this taxonomic change, D. longicauda was listed as Near Threatened under criterion A4c, on the basis that it was susceptible to habitat fragmentation and disturbance and following a model of Amazonian deforestation (Bird et al. 2012) the population was suspected to decline by 25-30% over the next 3 generations (BirdLife International 2016).

D. longicauda (as defined now following the taxonomic changed) is found in the Guianas and northern Brazil, north of the Amazon River. D. typica is found in Costa Rica, Panama, Colombia, Nicaragua and potentially Honduras. Both species are found in lowland humid forest, and may be susceptible to habitat fragmentation and disturbance (Marantz et al. 2016). The pre-split species was most common in Costa Rica (Marantz et al. 2016), and while there has been habitat loss elsewhere in D. typica’s range it remains relatively common. Habitat loss has been less intense over the past 3 generations within the range of D. longicauda than in other parts of the pre-split species’s range, and declines due to habitat loss are not thought to approach the threshold for Vulnerable. Therefore, it is suspected that neither of these two species will approach the threshold for Vulnerable and would warrant listing as Least Concern.

D. pallida is found across large areas of South America, occurring in Amazonian Brazil, Colombia, Venezuela, Ecuador, Peru and Bolivia. This species is found in humid forest in lowlands and Andean foothills (Marantz et al. 2016), where habitat destruction may be of a particular concern. The analysis of the pre-split species by Bird et al. (2012) suggested the pre-split D. longicauda would lose up to 15.4% of its suitable habitat over 3 generations due to Amazonian deforestation. The species was however, particularly affected by habitat disturbance and fragmentation (see Marantz et al. 2016), and so population declines were suspected to be greater than the rate of habitat loss. It is thought that the threats for the pre-split species that warranted its listing as Near Threatened (BirdLife International 2016) are particularly relevant and applicable for this taxon and so it is suspected that D. pallida may be undergoing at least a moderate decline (potentially 25-30% decline within 3 generations [c.12 years]). Therefore, it is proposed that this species be listed as Near Threatened under criteria A3c+4c.

Comments are invited on these proposed categories and further information would be welcomed.

References:

Bird, J. P., Buchanan, G. M., Lees, A. C., Clay, R. P., Develey, P. F., Yépez, I. and Butchart, S. H. M. 2012. Integrating spatially explicit habitat projections into extinction risk assessments: a reassessment of Amazonian avifauna incorporating projected deforestation. Diversity and Distributions 18: 273-281.

BirdLife International 2016. Species factsheet: Deconychura longicauda. Downloaded from http://www.birdlife.org on 05/10/2016.

Marantz, C.A., Aleixo, A., Bevier, L.R. and Patten, M.A. 2016. Long-tailed Woodcreeper (Deconychura longicauda). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved fromhttp://www.hbw.com/node/56600 on 27 September 2016).

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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2 Responses to Archived 2016 topics: Long-tailed Woodcreeper (Deconychura longicauda) is being split: list D. longicauda and D. typica as Least Concern and D. pallida as Near Threatened?

  1. Chris Sharpe says:

    The distribution of connectens (part of the proposed D. (l.) pallida) extends several hundred km further north in Venezuela than shown on BirdLife maps – into NW Bolívar State (see Hilty). A 110,000 km2 swathe of N Bolívar was designated as the Arco Minero del Orinoco (Orinoco Mining Arc) earlier this year, and is destined for large-scale gold-coltan-iron-bauxite mining, with consequent deforestation. This large projected forest loss is too recent to have been taken into account in published models, but a serious conservation impact on all forest-dependent Guayanan species is to be anticipated. It will affect the part of connectens‘s range that is not currently shown on the BirdLife maps.

    On the other hand, a significant chunk of the distribution of D. (l.) pallida falls within some very large and relatively secure strict protected areas. To take Venezuela’s Amazonas State as an example, connectens is found, or potentially occurs, in Duida-Marahuaca (2100 km2), Serranía de La Neblina (13600 km2) and Parima-Tapirapecó (39,000 km2) National Parks (all IUCN Cat. II), which collectively form part of the Alto Orinoco-Casiquiare Biosphere Reserve (IUCN Cat. VI; 84,000 km2), as well as Cerro Yapacana NP (3200 km2). Admittedly, a fair proportion of these parks is mountainous land above the elevational range of Deconychura, but the total area of suitable habitat protected is still very extensive.

    Whether this combination results in an assessment of NT could be judged by mapping. I am not clear on the precise distribution of the split taxa.

  2. James Westrip (BirdLife) says:

    Based on available information, our preliminary proposal for the 2016 Red List would be to list:

    D. longicauda and D. typica as Least Concern.

    D. pallida conservatively as Near Threatened under criteria A3c+4c.

    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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