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.
Pompadour Green-pigeon Treron pompadora is being split into T. pompadora, T. affinis, T. chloroptera, T. phayrei, T. axillaris and T. aromatica, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, T. pompadora (BirdLife species factsheet) was listed as Least Concern on the basis that it was not thought to approach the thresholds for Vulnerable under any of the IUCN criteria. This species was estimated to have an extremely large range, and hence did not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence [EOO] of less than 20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appeared to be stable, and hence the species did not approach the thresholds for Vulnerable under the population trend criterion (at least a 30% decline over ten years or three generations). The population size has not been quantified, but it was not believed to approach the thresholds for Vulnerable under the population size criterion (fewer than 10,000 mature individuals with a continuing decline estimated to be at least 10% over ten years or three generations, or with a specified population structure).
The newly-defined species resulting from this split are generally characterised as inhabitants of primary, secondary and logged forest, and thus show moderate to high forest dependency but some tolerance of habitat modification.
T. aromatica is endemic to Buru (Gibbs et al. 2001, Collar 2011) and may qualify as Vulnerable under criterion B1ab(ii,iii,v), if its habitats are deemed to be severely fragmented (over 50% in patches too small to support viable populations) as it occupies a small range (with an EOO estimated at c.8,600 km2), in which suitable habitat is declining in area and quality, driving declines in the species’s population.
T. pompadora is endemic to Sri Lanka (Gibbs et al. 2001) and may qualify as Near Threatened under criteria A2cd+3cd+4cd, on the basis that it could be in moderately rapid population decline (approaching 30% over three generations [c.13 years]) owing to on-going habitat loss and degradation and hunting pressure.
T. chloroptera is found in the Andaman and Nicobar islands (Gibbs et al. 2001) and may qualify as Near Threatened under criteria A2d+3d+4d; B1ab(v); C2a(i), on the basis that it has a small to moderately small population, which occupies a small range (with an EOO estimated at c.6,700 km2) in which suitable habitat is declining in area and quality and may be very fragmented (approaching 50% in patches too small to support viable populations), and it is suspected to be in moderately rapid population decline (approaching 30% over three generations [c.13 years]) owing to habitat changes and extensive hunting pressure.
T. phayrei is widely distributed in Nepal, Bangladesh, eastern India and much of Indochina (see Collar 2011). It may qualify as Near Threatened under criteria A2cd+3cd+4cd, on the basis that it could be undergoing a moderately rapid population decline (approaching 30% over three generations [c.13 years]) owing to widespread habitat loss and hunting pressure.
T. axillaris is widely distributed in the Philippines (Collar 2011) and may qualify as Near Threatened under criteria A2cd+3cd+4cd, on the basis that it could be in moderately rapid population decline (approaching 30% over three generations [c.13 years]) owing to habitat loss and degradation and hunting pressure.
T. affinis is found in southern India (Gibbs et al. 2001, Collar 2011) and is likely to qualify 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:
Collar, N. J. (2011) Species limits in some Philippine birds including the Greater Flameback Chrysocolaptes lucidus. Forktail 27: 29-38.
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.
Related posts:
- Whistling Green-pigeon (Treron formosae) is being split: list T. formosae as Near Threatened?
- Javan Frogmouth (Batrachostomus javensis) and Blyth’s Frogmouth (B. affinis) are being lumped as B. javensis: list the newly defined species as Near Threatened?
- Green-backed Kingfisher (Actenoides monachus) is being split: list both A. monachus and A. capucinus as Near Threatened?
- Cinnamon-bellied Imperial-pigeon (Ducula basilica) is being split: list D. obiensis as Near Threatened?
- Archived 2011-2012 topics: Taxonomic change in the genus Cissa: list Javan Green Magpie (C. thalassina) as Critically Endangered and Bornean Green Magpie (C. jefferyi) as Least Concern?
Based on status in Lao PDR, there is a much better case for T. phayrei to be considered something other than LC than for Bay Owl and Banded Kingfisher. This pigeon is strikingly localised (but without obvious habitat-characters that allow one to predict where else it might be likely to occur) and in most parts of Lao with recent records, they are of only small numbers. It is much more localised in Lao than other green pigeon species, notably Thick-billed, Pin-tailed, Yellow-vented, Orange-breasted and Yellow-footed. If this is representative of its wider range, then certainly NT (or worse – VU could easily be countenanced for Lao, nationally) warrants consideration.