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.
Chestnut-necklaced Partridge Arborophila charltonii is being split into A. charltonii, A. tonkinensis and A. graydoni, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, A. charltonii (BirdLife species factsheet) was listed as Near Threatened under criteria A2cd+3cd+4cd, on the basis that its population was suspected to be undergoing a moderately rapid decline (approaching 30% over 16 years [estimate of three generations]) owing to on-going and rapid logging and prevalent trapping pressure.
A. graydoni is endemic to Borneo, where it is found in lowland primary dipterocarp forest, to 800 m (Myers 2009), although it has also been recorded in a tree plantation (Phillipps and Phillipps 2011), and it has been suggested that a few hundred probably survive in partially logged forest (Madge and McGowan 2002). It is described as locally common (Myers 2009, Phillipps and Phillipps 2011), and within the vast Danum Valley (its stronghold) it appears to be very common (BirdLife International 2001). It is suggested that this species be listed as Vulnerable under criterion C2a(ii), on the basis that its population is likely to number fewer than 10,000 mature individuals, all in a single subpopulation, with on-going declines inferred owing to continued habitat destruction and potential hunting pressure.
A. tonkinensis is found in Tonkin, Vietnam, where it inhabits dense lowland forest, and probably also secondary and logged forest, up to 500 m (Madge and McGowan 2002). It is described as locally common and occurs in at least three protected areas (BirdLife International 2001, Madge and McGowan 2002). It is suggested that this species be listed as Vulnerable under criterion C2a(ii), on the basis that its population is likely to number fewer than 10,000 mature individuals, all in a single subpopulation, and inferred to be in continuing decline owing to on-going habitat fragmentation and expected levels of hunting pressure.
A. charltonii (as defined following the taxonomic change, and incorporating atjenensis) is found in the Thai-Malay Peninsula and Sumatra (Madge and McGowan 2002). It is suggested that this species be listed as Vulnerable under criterion C2a(i), on the basis that it is likely to have a population of fewer than 10,000 mature individuals (perhaps fewer than 2,500, as the nominate may number fewer than 1,000 individuals, and atjenensis fewer than 100 [BirdLife International 2001, Madge and McGowan 2002]), with no subpopulations numbering more than 1,000 mature individuals (although probably more than 250 in at least one case, hence not thought to meet the thresholds for Endangered), and with an on-going population decline inferred owing to continued habitat destruction and expected hunting pressure.
Comments on these suggested categories and further information would be welcomed.
BirdLife International (2001) Threatened Birds of Asia: The BirdLife International Red Data Book. Cambridge, UK: BirdLife International.
Madge, S. and McGowan, P. (2002) Pheasants, partridges and grouse: including buttonquails, sandgrouse and allies. London, UK: Christopher Helm (Helm Identification Guide).
Myers, S. (2009) A field guide to the birds of Borneo. London, UK: New Holland.
Phillipps, Q. and Phillipps, K. (2011) Phillipps’ field guide to the birds of Borneo. Second edition. Oxford, UK: John Beaufoy Publishing.
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.