This is part of a consultation on the Red List implications of extensive changes to BirdLife’s taxonomy for non-passerines
Lynx Edicions and BirdLife International will soon publish 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 1 of the checklist (for non-passerines) will begin to be incorporated into the 2014 Red List update, with the remainder, and those for passerines (which will appear in volume 2 of the checklist), 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.
Sunda Teal Anas gibberifrons is being split into A. gibberifrons and A. albogularis, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, A. gibberifrons (BirdLife species factsheet) was listed as being of Least Concern, on the basis that it was not thought to approach the thresholds for Vulnerable under any of the IUCN criteria.
A. albogularis is endemic to Andaman Islands and Great Coco Island, where it inhabits freshwater streams, ponds and lagoons, paddy-fields, freshwater and brackish swamps, tidal creeks and estuaries (Kear 2005, Rahmani and Islam 2008). It is nomadic and alights on the sea, as well as being present on many islands (Rahmani and Islam 2008). It has been noted that human disturbance to the species’s habitat, through activities such as irrigation, fishing and hunting, is considerable (Rahmani and Islam 2008). Very little of its habitat is protected, and historically the largest flocks have been recorded in the least disturbed areas. Despite the threat of disturbance, and past declines, numbers on the Andaman Islands appear to be stable or increasing, with 69-582 individuals counted in 1995-1998, and 674 individuals counted in 2003-2004 (Vijayan et al. 2006).
With recent survey data in mind, the species is estimated to have a total population of 500-1,000 individuals (Wetlands International 2006, Rahmani 2012), which is said to be increasing (Rahmani 2012). It is on this basis that the recommendation of Rahmani (2012) is followed and it is suggested that the species qualifies as Vulnerable under criterion D, because its population probably includes fewer than 1,000 mature individuals and is not thought to be in decline.
A. gibberifrons (as defined following the taxonomic change) is thought likely to warrant listing as Least Concern, on the basis that it is not thought to approach the thresholds for Vulnerable under any of the IUCN criteria.
Comments are invited on these suggested categories and further information would be welcomed.
Kear, J. (2005) Ducks, geese and swans volume 2: species accounts (Cairina to Mergus). Oxford, UK: Oxford University Press (Bird families of the world 16).
Rahmani, A. R. (2012) Threatened Birds of India – Their Conservation Requirements. Indian Bird Conservation Network: Bombay Natural History Society, Royal Society for the Protection of Birds and BirdLife International. Oxford, UK: Oxford University Press.
Rahmani, A. R. and Islam, M. Z. (2008) Ducks, geese and swans of India: Their status and distribution. Indian Bird Conervation Network: Bombay Natural History Society, Royal Society for the Protection of Birds and BirdLife International. Oxford, UK: Oxford University Press.
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.
Vijayan, L., Murugan, V. and Raja Mamannan, M. A. (2006) Conservation of Andaman Teal. TWSG News 15: 55-59.
Wetlands International (2006) Waterbird population estimates. Fourth edition. Wageningen, The Netherlands: Wetlands International.