Whistling Green-pigeon (Treron formosae) is being split: list T. formosae as Near Threatened?

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 2013 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.

Whistling Green-pigeon Treron formosae is being split into T. formosae and T. permagnus, following the application of criteria set out by Tobias et al. (2010).

Prior to this taxonomic change, T. formosae (BirdLife species factsheet) was listed as Near Threatened under criterion C1, on the basis that it was thought to have a moderately small population, which was inferred to be declining mainly as a result of hunting and habitat degradation.

T. formosae (as defined following the taxonomic change, and incorporating filipina) occurs on Lanyu Island and Taiwan (China), Batan, Calayan, Camiguin Norte and Sabtang (Philippines), where it occupies forest and modified wooded habitats (del Hoyo et al. 1997, Gibbs et al. 2001, N. J. Collar in litt. 2012). It is suggested that it qualifies as Near Threatened under criterion C1, on the basis that it is likely to have a moderately small population, which is thought to be in decline owing to habitat loss and hunting pressure, although the rate of decline has not been estimated.

T. permagnus (incorporating medioximus) occurs in the Ryukyu Islands (Japan) and inhabits forest and modified habitats such as cultivated areas and gardens with trees (del Hoyo et al. 1997, Gibbs et al. 2001). It 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.

References:

del Hoyo, J., Elliott, A. and Sargatal, J. (1997) Handbook of the birds of the world, Vol 4: Sandgrouse to Cuckoos. Barcelona, Spain: Lynx Edicions.

Gibbs, D., Barnes, E. and Cox, J. (2001) Pigeons and doves: a guide to the pigeons and doves of the world. Robertsbridge, U.K.: Pica 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.

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