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.
Shrike-like Cotinga L. elegans is being split into L. elegans (Elegant Mourner) and L. buckleyi (Andean Mourner), following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, L. elegans was listed as Least Concern, on the basis that it did not approach the threshold for Vulnerable under any criteria. L. elegans had only relatively recently been lumped with L. buckleyi (BirdLife International 2016) and so this split represents a taxonomic ‘re-split’ now that the criteria set out by Tobias et al. (2010) have been applied. Prior to the two species being lumped L. buckleyi was listed as Least Concern. It occurs in primary and mature secondary forest on the lower eastern slope of the Andes in Venezuela, Colombia, Ecuador, Peru and Bolivia, and there is likely to be ongoing habitat destruction. Snow and Sharpe (2016) suggest that the newly split species may be considered as Vulnerable on the basis that much of its habitat in foothill forest has been removed and replaced with agriculture and livestock. L. buckleyi has a very large EOO, and is suspected to have a population of >10,000 mature individuals, therefore the species would not qualify as Vulnerable under criteria B, C or D. If the species is shown to have undergone, be undergoing, or will undergo a decline in the magnitude of >30% within 3 generations (c.14 years) then it would qualify as Vulnerable under criterion A2c+3c+4c. We therefore request any information regarding whether declines may be of this magnitude within the past 3 generations, but if declines may have occurred outside this timeframe this species may warrant listing as Least Concern.
Before being lumped with L. buckleyi, L. elegans was listed as Near Threatened under criteria A2c+3c. Prior to that it had been listed as Vulnerable, but had subsequently be found at several new locations and, while habitat loss was still likely to be affecting it, declines were no longer believed to be of a sufficient magnitude to warrant listing as Vulnerable. It is found in Atlantic forest in Brazil from south Bahia to São Paulo and east Paraná (Snow and Sharpe 2016), and while habitat clearance is occurring in this area, the amount that has occurred within the past 3 generations may not approach sufficient levels to warrant listing as Vulnerable. The species is now listed as Near Threatened on the national Red List for Brazil.
We request any further information regarding the magnitude of potential declines in this species to see whether it would qualify to be listed as Near Threatened, but in the absence of any evidence for significant declines it may warrant listing as Least Concern.
Comments are invited on these proposed categories and further information would be welcomed.
BirdLife International 2016. Species factsheet: Laniisoma elegans. Downloaded from http://www.birdlife.org on 23/09/2016.
Snow, D. and Sharpe, C.J. 2016. Elegant Mourner (Laniisoma elegans). 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 from http://www.hbw.com/node/57000 on 23 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.