Archived 2014 discussion: Chestnut-necklaced Partridge (Arborophila charltonii) is being split: list A. graydoni, A. tonkinensis and A. charltonii as Vulnerable?

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.

References:

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.

Related posts:

  1. Archived 2011-2012 topics: White-necklaced Partridge (Arborophila gingica): downlist to Near Threatened?
  2. Archived 2014 discussion: Dwarf Black Hornbill (Tockus hartlaubi) is being split: list T. hartlaubi as Near Threatened?
  3. Archived 2014 discussion: Crestless Fireback (Lophura erythopthalma) is being split: list both L. erythopthalma and L. pyronota as Vulnerable?
  4. Archived 2014 discussion: Crested Fireback (Lophura ignita) is being split: list both L. ignita and L. rufa as Near Threatened?
  5. Archived 2011-2012 topics: Rock Partridge (Alectoris graeca): uplist to Near Threatened?
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9 Responses to Archived 2014 discussion: Chestnut-necklaced Partridge (Arborophila charltonii) is being split: list A. graydoni, A. tonkinensis and A. charltonii as Vulnerable?

  1. Simon Mahood says:

    These species are probably no more threatened than e.g. Orange-necked Partridge and consequently should placed in the same threat category: Near Threatened.

  2. Yong Ding Li says:

    A. charltonii would deserve at least a vulnerable, in view of its rarity and apparently dependance on plains-level and riparian forest. I am not aware of any records of the species, even from camera-trap data in Sumatra’s lowlands even though Black Partridge have been documented in recent camera-trapping surveys. The species must be occuring at very low density, or is local in Sumatra given the scarcity of records. There have not been any definitive records of the species in Pen. Malaysia for years, I have recorded it once in lowland forest in Kenyir lake region in 2007, but am not aware of records even in apparently suitable habitat in mostly lowland Taman Negara National Park or Endau Rompin NP.

  3. I’m not familiar with any of these areas but given the resilience of congeners in non-Sundaic SE Asia to hunting and habitat degradation (notably the close relative in Lao) I wonder if, for the Tonkin taxon, there may be the same sort of alarmist overlisting that characterised various other SE Asian galliform species until recently. If its status in remaining habitat reflects that of the Lao form (which from memory of other people’s comments about its status a decade or so ago, it does), then it is scarcely credible that only 10,000 mature individuals exist. It would be interesting to see the background for how this was derived.

  4. Yong Ding Li says:

    This is an update to my earlier comment. Apparently there has been one or two lowland forest sites (Ulu Muda and Pedu Forest Reserves) in northern Peninsular Malaysia where Chestnut-necklaced Partridge has been recorded recently. However there is no data on abundance. Given the proximity and similarity of forest types, presumably the species also occurs in the Hala-Bala Wildlife Sanctuary across the Thai border

  5. R. J. Timmins says:

    Leaving aside the fact that A. tonkinensis is surely most closely related to A. chloropus and almost certainly no more than a geographic variant of that species (showing pleisiomorphic characters), a Vulnerable listing would be tenuous and as Will suggests ‘alarmist’. The apparent population guestimate of <10,000 is very likely way off the mark perhaps by an order of magnitude, admidedly now split into numerous sub-populations, but occuring surely in many PAs, and highly resilient to hunting pressure in typical regional galliform fashion. Even NT might be too alarmist.

  6. James Eaton says:

    I have recorded A. charltonii in northernmost Malaysia, at Ulu Mudu, right besides a camp that does suffer from hunting pressures (though of an unknown scale). Given that Ulu Mudu is part of the huge forest complex on the Malaysia-Thailand border I assume it is still found in healthy numbers in a large area of this. It does not appear to occur further south however, ie inside Taman Negara National Park on current knowledge.

  7. Simon Mitchell says:

    In my experience A. graydoni is almost as common in dense disturbed habitats in Sabah as in primary dipterocarp forests. It is still frequent along the Kinabatangan River, despite continued habitat fragmentation and destruction there.

  8. 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:

    A. charltonii as Vulnerable under criterion C2a(i)

    A. graydoni as Least Concern

    A. tonkinensis 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.

  9. 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.