Archived 2014 discussion: Blue-throated Barbet (Megalaima asiatica) is being transferred into the genus Psilopogon and is being split: request for information on P. chersonesus

The initial deadline for comments on this topic is 28 April 2014, and therefore later than for most other topics currently under discussion.

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.

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.

Blue-throated Barbet Megalaima asiatica is being transferred into the genus Psilopogon and is being split into P. asiaticus (Blue-throated Barbet) and P. chersonesus (Turquoise-throated Barbet), following the application of criteria set out by Tobias et al. (2010).

Prior to the taxonomic change, M. asiatica (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 Red List criteria.

The newly-defined P. asiaticus (incorporating P. a. davisoni) has an extremely large range from northeast Pakistan east along the Himalayas to northern Myanmar and southern China. It is generally common almost everywhere within its range and is an adaptable species, occurring in primary and secondary mountain forest, clearings, edges, orchards, plantations and gardens, and entering towns and cities where there are fruiting trees (Short and Horne 2002). It is not thought to approach the thresholds for Vulnerable under any of the IUCN Red List criteria and is therefore proposed to be listed as Least Concern.

P. chersonesus is restricted to east peninsular Thailand, where it is present from the Surat Thani/Nakhon Si Thammarat divide south to the limit of montane forest at 8˚ˊ15ˊN (Wells 1999). It is apparently not uncommon within its small range (del Hoyo et al. 2002). It occurs in montane forest from 885 m to at least 1,520 m (Wells 1999) within an Extent of Occurrence estimated at c.850 km2.

It occurs in at least one conservation area (Khao Luang) and has not been considered at risk except on the basis of its restricted range (Wells 1999, del Hoyo et al. 2002). The population size has not been estimated, but if it as adaptable and frequent within its range as P. asiaticus its population may not be very small.

If the species is not thought to be undergoing, or predicted to undergo, declines in its range or population, or the area, extent or quality of habitat, it is not estimated to number fewer than c,1,500 mature individuals, and there is no plausible threat that could cause very rapid future declines, it may warrant classification as Least Concern despite its restricted range.

However, if it is inferred to be declining or projected to undergo declines it may instead warrant classification as Vulnerable if the population is estimated to contain fewer than 10,000 mature individuals, or if the range is severely fragmented. If any of these thresholds are approached, but not met, it may warrant listing as Near Threatened.

Comments are invited on the likely population size, trend, and threats to P. chersonesus, and the extent to which its habitat is fragmented, and any further information on the species would be welcomed.

References

del Hoyo, J., Elliott, A. & Sargatal, J. eds. (2002). Handbook of the Birds of the World. Vol. 7. Jacamars to Woodpeckers. Lynx Edicions, Barcelona.

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.

Wells, D. R. 1999. The Birds of the Thai-Malay Peninsula. Vol 1. Non-passerines. Academic Press, London.

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3 Responses to Archived 2014 discussion: Blue-throated Barbet (Megalaima asiatica) is being transferred into the genus Psilopogon and is being split: request for information on P. chersonesus

  1. Andy Symes says:

    Preliminary proposals

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

    P. asiaticus and P. chersoneus as Least Concern

    There is now a period for further comments until the final deadline of 14 May, 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.

  2. 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 in mid-2014, following further checking of information relevant to the assessments by BirdLife and IUCN.

  3. This species is very common in my location in southern Assam, India. – Lat 24.43202, Lon 92.330689

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