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.
Blue Chaffinch Fringilla teydea is being split into F. teydea and F. polatzeki, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, F. teydea (http://www.birdlife.org/datazone/species/factsheet/22720036) was listed as Near Threatened under D2, on the basis that it had small range and moderately small population, but because the population on Tenerife was suspected to be increasing in line with an increase in area of suitable habitat it did not sufficiently meet any criteria to be listed as Vulnerable. F. teydea (as now defined following the taxonomic change) is found only on Tenerife, Spain, and is suspected to be increasing due to an increase in the area of suitable habitat (Barov and Derhé 2011). The major threat to this species is from forest fires. The population size has been estimated at 1,000-2,500 pairs (2,000-5,000 mature individuals) (BirdLife International 2015). It is not thought to qualify as Vulnerable under any criteria, but its small range in combination with the ongoing threat from forest fires qualifies it to currently remain as Near Threatened under criterion D2.
F. polatzeki is found only on Gran Canaria, Spain, within a very restricted range. There are only an estimated 120-132 pairs on the island (BirdLife International 2015), found in pine forest. Illegal trade may be an issue (Clement and Sharpe 2016), but more severe for this species is continued habitat loss and fragmentation, for commercial gain and from forest fires (BirdLife International 2015; Clement and Sharpe 2016). Therefore, the species is inferred to be declining and may qualify as Critically Endangered under criterion C2a(ii) if the population size is at the mid-lower end of its estimate. Any evidence to suggest that the population is more likely to be at the higher end of this estimate, or even higher, would then mean the species warrants listing as Endangered under criterion C2a(ii).
Comments are invited on these proposed categories and further information would be welcomed.
Barov, B and Derhé, M. A. (2011). Review of the Implementation of Species Action Plans for Threatened Birds in the European Union 2004-2010. Final report. BirdLife International, for the European Commission.
BirdLife International (2015) European Red List of Birds. Office for Official Publications of the European Communities, Luxembourg.
Clement, P. and Sharpe, C. J. (2016) Blue Chaffinch (Fringilla teydea). 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/61287 on 26 August 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.