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.
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.