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.
Asian Pied Starling Gracupica contra is being split into Gracupica contra and Gracupica jalla, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, Sturnus contra (BirdLife species factsheet) was listed as Least Concern, on the basis that it did not approach the thresholds for listing as Vulnerable under any of the criteria. The pre-split species had a very large range extending from Pakistan in the northwest, across northern south Asia, through south east Asia to southern Thailand, and then separately in Sumatra, Java and Bali. It was characterised as generally common to fairly common, although rare and local in Pakistan, and the population trend was considered to be increasing.
Gracupica jalla (as defined following the taxonomic change) is the taxon found in Sumatra, Java and Bali. It may have been completely disappeared from the wild within the past 25 years. Common on Sumatra in 1975-77, there are no recent records from the island (Harris et al. 2015, Eaton et al. 2015). On Java and Bali there are a handful of records in the last 12 years, some of which relate to obvious escapes but a series of trapped birds in limestone hills in Central Java in 2010 (Eaton et al. 2015) may relate to the last genuine remnants of the wild population. The impact of pesticide use is thought to have potentially also caused population declines but capture for the wild bird trade is the biggest cause of the apparent loss of this species from the wild (Eaton et al. 2015). Several presumed escapes have been seen on Serangan Island, Bali, and have attempted to nest in recent years (eBird 2016a, Eaton et al. 2015).
Large numbers, apparently of this taxon, are being bred in commercial bird farms in central Java to supply the trade. However, imports of other taxa into Java and apparent mixing of these in captivity seem likely to have reduced the likelihood there being a source of G. jalla stock for conservation breeding (Collar et al. 2012, Eaton et al. 2015); while Chng et al. (2015) mention large numbers of likely captive-bred juveniles in Javan markets these are not listed as definitively this taxon in their appendix.
Any remaining wild population is likely to be tiny and clarifying the status (and indeed identity) of the birds currently at large within the species native range is a high priority.
It is proposed that the newly split species be listed as Critically Endangered, under criteria A2d+3d+4d; C2a(i); D.
Comments are invited on these proposed categories and further information would be welcomed.
Chng, S. C. L., Eaton, J. A., Krishnasamy, K., Shepherd, C. R. & Nijman, V. 2015. In the market for extinction: an inventory of Jakarta’s bird markets. Petaling Jaya, Selangor, Malaysia: TRAFFIC.
Collar, N. J., Gardner, L., Jeggo, D. F., Marcordes, B., Owen, A., Pagel, T., Pes, T., Vaidl, A., Wilkinson, R. & Wirth, R. 2012. Conservation breeding and the most threatened birds in Asia. BirdingASIA 18: 50–57.
Eaton, J.A., Shepherd, C.R., Rheindt, F.E., Harris, J.B.C., van Balen, S. (B.), Wilcove, D.S. and Collar, N.J. 2015. Trade-driven extinctions and near-extinctions of avian taxa in Sundaic Indonesia. Forktail 31: 1-12.
eBird 2016a. Steve Jones: Checklist S24210802. Denpasar, Jalan Pulau Serangan, Bali County, Nusa Tenggara, ID. http://ebird.org/ebird/view/checklist/S24210802. Accessed 25th August 2016.
Harris, J. B. C., Green, J. M. H., Prawiradilaga, D. M., Giam, X., Giyanto, Hikmatullah, D., Putra, C. A. & Wilcove, D. S. 2015. Using market data and expert opinion to identify overexploited species in the wild bird trade. Biol. Conserv. 187: 51–60.
IUCN (2001) IUCN Red List Categories and Criteria: Version 3.1. Gland, Switzerland and Cambridge, UK: IUCN Species Survival Commission.
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.