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-rumped Shama Copsychus malabaricus is being moved to genus Kittacincla and split into Kittacincla malabarica and K. albiventris, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, White-rumped Shama was listed as Least Concern, on the basis that it did not approach the threshold for Vulnerable under any criterion. Kittacincla malabarica (as now defined following the taxonomic change) has a large distribution across Southern and South East Asia, with a suspected very large population as the species has been described as common throughout most of its range (Collar 2016). It is not thought to approach the threshold for Vulnerable under any criterion, and so warrants listing as Least Concern.
K. albiventris is found only on the Andaman Islands in a range of lowland forest habitats (see Collar 2016). It appears to be able to tolerate a degree of habitat disturbance as the pre-split species could be found in secondary forest an overgrown plantations (Collar 2016). However, as the human population on the islands increases there is consequent habitat alteration to cultivation and grazing, as well as increased logging and development, thus there has been at least a decrease in the quality of the habitat available to this species. The population size of this species has not been quantified but the pre-split species was fairly common to common in much of its natural range (see Collar 2016) and so the population size may not approach the threshold for Vulnerable.
Several species have a similar range to K. albiventris, including Andaman Drongo, Dicrurus andamanensis, Andaman Woodpecker, Dryocopus hodgei, and Andaman Treepie, Dendrocitta bayleyi; all of which have been classed as Near Threatened under criterion B1 because of their restricted range (BirdLife International 2016). It is therefore proposed that K. albiventris also be listed as Near Threatened under criterion B1ab(iii) because it has a restricted range within which the species’s habitat is declining in quality, and approaches but does not meet the threshold for Vulnerable under the same criterion because the population is not severely fragmented and is likely found at >10 locations*. Any evidence that the population of this species is declining too as a result of habitat alteration would mean it may warrant listing as Near Threatened under criterion B1ab(iii,v).
Comments are invited on these proposed categories and further information would be welcomed.
*Note that the term ‘location’ defines a geographically or ecologically distinct area in which a single threatening event can rapidly affect all individuals of the taxon present. The size of the location depends on the area covered by the threatening event and may include part of one or many subpopulations. Where a taxon is affected by more than one threatening event, location should be defined by considering the most serious plausible threat (IUCN 2001, 2012).
BirdLife International 2016. IUCN Red List for birds. Downloaded from http://www.birdlife.org on 08/10/2016.
Collar, N. 2016. White-rumped Shama (Copsychus malabaricus). 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/58486 on 7 October 2016).
IUCN. 2001. IUCN Red List Categories and Criteria: Version 3.1. Gland, Switzerland and Cambridge, UK: IUCN Species Survival Commission.
IUCN. 2012. Guidelines for Application of IUCN Red List Criteria at Regional and National Levels: Version 4.0. Gland, Switzerland and Cambridge, UK: IUCN.
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.