Archived 2014 discussion: Pompadour Green-pigeon (Treron pompadora) is being split: list T. aromatica as Vulnerable and four other newly defined species 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 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.

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:

  1. Archived 2014 discussion: Whistling Green-pigeon (Treron formosae) is being split: list T. formosae as Near Threatened?
  2. Archived 2014 discussion: Variable Kingfisher (Ceyx lepidus) is being split: list C. dispar as Vulnerable and five other newly defined species as Near Threatened?
  3. Archived 2014 discussion: Javan Frogmouth (Batrachostomus javensis) and Blyth’s Frogmouth (B. affinis) are being lumped as B. javensis: list the newly defined species as Near Threatened?
  4. 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?
  5. Archived 2014 discussion: Pheasant Pigeon (Otidiphaps nobilis) is being split: list O. insularis as Endangered and O. aruensis as Vulnerable?
This entry was posted in Archive, Asia and tagged . Bookmark the permalink.

8 Responses to Archived 2014 discussion: Pompadour Green-pigeon (Treron pompadora) is being split: list T. aromatica as Vulnerable and four other newly defined species as Near Threatened?

  1. 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.

  2. In Buru island, Indonesia the population of this species has decreased in numbers drastically and the change can be clearly noticed from year 2006 to 2010. In 2006 I found this species fairly common in the forest patches surrounding Bara village in the far west of the island in small flocks of 5 to 9 birds. I have encountered locals hunting for these size pigeons, doves and parrots for food and that maybe one of the major factors in the decline in numbers.

  3. R. J. Timmins says:

    What Will writes for Laos, applies to large degree also for Cambodia. This suggests some natural element to it’s scarcity, but also quite possibly an element of susceptibility. Both in Laos and Cambodia, habitat changes and a propensity for hunting green pigeons suggests a bleak outlook for the species.

    • R. J. Timmins says:

      After 20 years I’ve finally seen T. phayrei in Indochina, in Cat Tien NP. Not only does the species appear to be common there (but probably somewhat less so than Thick-billed), but there appears nothing particularly unusual about the species behaviour or habitat association to suggest why the species is so scarce and enigmatic in Indochina as a whole. A number of hunting sensitive species (although not all) are doing surprisingly well in Cat Tien NP. My conclusion is that the species is presumably very sensitive to hunting pressure, and perhaps very reliant on Semi-Evergreen/Evergreen Forest at low elevations. The later factor would help explain why Thick-billed and even Green Imperial Pigeon are still widespread and relatively commoner in lowland forests than is T. phayrei, as both potentially have ‘large’ reservoir populations in hill areas, as well as the fact that the later appears to make greater use of more deciduous habitats. If such a conclusion is correct, the current pace of lowland forest loss is a serious concern for the species, while there is little indication that hunting pressure is diminishing except in some localised and generally small, ‘well’ managed sites.

  4. Craig Robson says:

    It is very hard to estimate numbers on Buru without some kind of systematic survey, and an assessment of the habitat requirements of this species. It has been seen in at least four separate areas by visiting birders recently, and some of these are predominantly marginal or non-forest areas. At present, I would not list it higher than Near Threatened. Remaining lowland forest and other lowland habitats have not been widely surveyed on Buru. Most birders visit the same limited areas.

  5. Frederic Goes says:

    I further go along the lines of Rob and Will re the species status in Cambodia, although it is not possible to assess the eventual decline trend, due to the short time span since the species was first recorded.

    Status: A rare to uncommon resident of semi-evergreen forest in lowlands and lower hills up to 450m. First recorded in 1996. Now confirmed from about 15 scattered localities, mostly in the north and northeast plus a few sites in the southwest. Recorded in small parties of usually less than ten birds, but one record of 20 birds. May undertake sporadic movements in response to food availability.

    Conservation: Near-Threatened in Cambodia. The species is nowhere common or numerous and apparently occurs at low densities in Cambodia. There are 1–3 records annually, and few areas where it is regularly encountered. Southern Mondolkiri appears to be the stronghold in Cambodia. The species is mainly threatened by widespread trapping of forest pigeons for food and nest harvesting for local trade.

  6. Joe Taylor says:

    Preliminary proposals

    Based on available information and comments posted above, our preliminary proposals for the 2014 Red List would be to treat:

    T. pompadora as Least Concern

    T. aromatica as Near Threatened under criterion C2a(ii)

    T. chloroptera as Near Threatened under criterion C2a(i)

    T. phayrei as Near Threatened under criteria A2cd+3cd+4cd

    T. axillaris as Least Concern

    T. affinis as Least Concern

    There is now a period for further comments until the final deadline of 31 March, after which recommended categorisations will be put forward to IUCN.

    The final Red List categories will be published on the BirdLife and IUCN websites in mid-2014, following further checking of information relevant to the assessments by both BirdLife and IUCN.

  7. Andy Symes says:

    Recommended categorisations to be put forward to IUCN

    Following further review, there have been no changes to our preliminary proposals for the 2014 Red List status of these species.

    The final categorisations will be published later in 2014, following further checking of information relevant to the assessments by BirdLife and IUCN.

Comments are closed.