Archived 2014 discussion: Maroon-chinned Fruit-dove (Ptilinopus subgularis) is being split: list both P. subgularis and P. mangoliensis as Vulnerable and P. epia 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.

Maroon-chinned Fruit-dove Ptilinopus subgularis is being split into P. subgularis, P. mangoliensis and P. epia, following the application of criteria set out by Tobias et al. (2010).

Prior to this taxonomic change, P. subgularis (BirdLife species factsheet) was listed as Near Threatened under criteria A2c+3c+4c, on the basis that it was suspected to be undergoing a moderately rapid population decline (approaching 30% over 10 years) owing to intense logging activities in the lowland primary and secondary forest required by the species.

P. subgularis (as defined following the taxonomic change) is restricted to the islands of Peleng and Banggai (de Hoyo et al. 1997, Gibbs et al. 2001). The species may be threatened by habitat loss. By 1991, logging had begun in the last remaining areas of primary habitat on Peleng, which is expected to lead to further encroachment by shifting cultivators as a result of improved access (Indrawan et al. 2010). Exploration by mining companies could also lead to more habitat loss on Peleng in the near future (M. Indrawan in litt. 2007, 2008). This species’s population size has apparently not been quantified, but it may qualify as Near Threatened or Vulnerable under criterion C2a(ii), if there are thought to be fewer than or approaching as few as 10,000 mature individuals in the population, probably forming a single subpopulation, which is inferred to be in continuing decline owing to on-going habitat loss.

P. mangoliensis is found on the islands of Mangole and Taliabu (del Hoyo et al. 1997, Gibbs et al. 2001). Stones et al. (1997) describe the taxon as common and widespread on Taliabu, occurring mostly in lowland forest, but ranging up to 900 m. Similarly, Rheindt (2010) notes it to be commonly heard up to 1,100 m on Taliabu.

In the 1990s, it was reported that a substantial proportion of Taliabu was still forested, but that since 1970 large-scale logging of lowland forest had taken place, principally selective logging but also clear-felling of some areas (Davidson et al. 1995). It was also reported that most forest below 800 m was under logging concession and that other threats to forest included the expansion of shifting and permanent agriculture (Davidson et al. 1995). Following a visit in 2009, Rheindt (2010) speculated that all primary forest could have been lost from Taliabu due to the widespread activities of logging companies, with some areas converted to plantations, cultivation and gardens and further conversion to agriculture expected. In addition, forest fires have severely reduced and degraded montane forest on Taliabu (Rheindt 2010).

This species’s population size has apparently not been quantified, but it may qualify as Near Threatened or Vulnerable under criterion C2a(ii), if the number of mature individuals in the population is thought to be fewer than or approaching as few as 10,000, and probably forming a single subpopulation, which is inferred to be in continuing decline owing to on-going habitat loss and degradation.

P. epia is distributed throughout much of Sulawesi, where it is described as not uncommon, and inhabits primary and secondary forest from sea-level to c.600 m (del Hoyo et al. 1997, Gibbs et al. 2001). It has also been recorded in cacao plantations (Abrahamczyk et al. 2008), as well as selectively logged forest (Riley and Mole 2001). This species is thought to be in decline owing to on-going deforestation, but the rate of forest loss in its range may be relatively slow.  Miettinen et al. (2011) estimate the rate of forest loss on Sulawesi to be 10.8% between 2000 and 2010. This suggests that the species is unlikely to be undergoing a decline that approaches a rate of 30% over 10 years, and therefore may not qualify as Near Threatened, unless it is thought to be subject to substantial hunting pressure. It is suggested that this species is likely to be deemed of Least Concern, on the basis that it is not thought to approach the thresholds for Vulnerable under any of the IUCN Red List criteria.

Comments are invited on these suggested categories and further information would be welcomed.

References:

Abrahamczyk, S., Kessler, M., Putra, D. D., Waltert, M. and Tscharntke, T. (2008) The value of differently managed cacao plantations for forest bird conservation in Sulawesi, Indonesia. Bird Conservation International 18: 349–362.

Davidson, P., Stones, T. and Lucking, R. (1995) The conservation status of key bird species on Taliabu and the Sula Islands, Indonesia. Bird Conservation International 5: 1–20.

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.

Indrawan, M., Masala, Y., Dwiputra, D., Mallo, F. N., Maleso, A., Salim, A., Masala, F., Tinulele, I., Pesik, L., Katiandagho and Sunosol, D. S. (2010) Rediscovery of the Critically Endangered Banggai Crow Corvus unicolor on Peleng Island, Indonesia, part 1: ecology. Bulletin of the British Ornithologists’ Club 130(3): 154­–165.

Miettinen, J., Chenghua Shi and Soo Chin Liew (2011) Deforestation rates in insular Southeast Asia between 2000 and 2010. Global Change Biology 17: 2261–2270.

Rheindt, F. E. (2010) New biogeographical records for the avifauna of Taliabu (Sula Islands, Indonesia), with preliminary documentation of two previously undiscovered taxa. Bulletin of the British Ornithologists’ Club 130(1): 33–51.

Riley, J. and Mole, J. (2001) Birds of Gunung Ambang Nature Reserve, North Sulawesi, Indonesia. Forktail 17: 57–66.

Stones, A. J., Lucking, R. S., Davidson, P. J. and Wahyu Raharjaningtrah (1997) Checklist of the birds of the Sula Islands (1991), with particular reference to Taliabu Island. Kukila 9: 37–55.

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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  2. Archived 2014 discussion: Crested Serpent-eagle (Spilornis cheela) is being split: list S. minimus as Near Threatened? (Discussion now being closed)
  3. Archived 2014 discussion: Blue-rumped Parrot (Psittinus cyanurus) is being split: list P. abbotti as Vulnerable and P. cyanurus as Near Threatened?
  4. Archived 2012-2013 topics: Maroon-faced Parakeet (Pyrrhura leucotis): redefinition of species limits requires reassessment of Red List status
  5. Archived 2012-2013 topics: Kofiau Paradise-kingfisher (Tanysiptera ellioti): downlist to Vulnerable or Near Threatened?
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2 Responses to Archived 2014 discussion: Maroon-chinned Fruit-dove (Ptilinopus subgularis) is being split: list both P. subgularis and P. mangoliensis as Vulnerable and P. epia as Near Threatened?

  1. Joe Taylor says:

    Preliminary proposals

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

    P. subgularis as Vulnerable under criterion C2a(ii)

    P. mangoliensis as Near Threatened under criterion C2a(ii)

    P. epia 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.

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

Comments are closed.