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.
White-winged Magpie Urocissa whiteheadi is being split into U. whiteheadi and U. xanthomelana, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, U. whiteheadi was listed as Least Concern, on the basis that it did not approach the threshold for Vulnerable under any criterion. U. whiteheadi (as now defined following the taxonomic change) is found only on the island of Hainan, China, in the forest that remains on the island (Madge 2016). There was extensive deforestation on Hainan during the Chinese Cultural Revolution, and forest continues to be lost on the island (Madge 2016, see Global Forest Watch webpage: http://www.globalforestwatch.org/map). The continuing loss of forest means this species is likely in decline.
The species has been described as rare, and when reported it is only found in small numbers in the remnant forest on Hainan, particularly on the south of the island (Madge 2016). Its scarcity and population structure mean this species likely approaches or meets the threshold for Vulnerable under criterion C2a(ii) (a declining population of <10,000 mature individuals, with all individuals found in a single sub-population). Therefore, the species likely warrants listing as either Vulnerable or Near Threatened under this criterion.
U. xanthomelana is widespread on mainland Asia, occurring in southern China, northern Vietnam and northern and central Laos (Madge 2016). It is not thought to approach the threshold for Vulnerable under any criterion and so it would warrant listing as Least Concern.
Comments are invited on these proposed categories and further information would be welcomed.
Madge, S. 2016. White-winged Magpie (Urocissa whiteheadi). 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/60737 on 7 October 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.