Archived 2014 discussion: Amethyst Brown-dove (Phapitreron amethystina) is being split: list P. maculipectus as Endangered and P. frontalis as Critically Endangered (Possibly Extinct)?

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.

Amethyst Brown-dove Phapitreron amethystina is being split into P. amethystina, P. maculipectus and P. frontalis, following the application of criteria set out by Tobias et al. (2010).

Prior to this taxonomic change, P. amethystina (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.

P. maculipectus is known from Negros and Panay in the Philippines. It has been characterised as rare on Negros and its status on Panay remains uncertain (Gibbs et al. 2001). There had apparently been a dearth of recent records on Negros, until it was recorded in North Negros Natural Park in May 2008 (Pedregosa-Hospodarsky 2009). The species was also photographed at Twin Lakes, Negros, in February 2013 (Hutchinson 2013). Further records are requested.

The apparent shortage of information on this species makes an assessment of its threat status difficult, but its rarity suggests that the population numbers fewer than 2,500 mature individuals overall. On-going deforestation in its range implies that the population is likely to be in decline. If the populations on Negros and Panay are regarded as separate subpopulations (likely to exchange no more than one individual per year), and each probably numbers fewer than 250 mature individuals, the species may qualify as Endangered under criterion C2a(i). If each subpopulation is thought to number between 250 and 1,000 mature individuals, the species may qualify as Vulnerable under the same criterion.

P. frontalis is known from Cebu, where it has been considered probably extinct (Dutson et al. 1993), after it was apparently last recorded in 1892 (Rabor 1959). However, in November 2004 two possible individuals were observed in Alcoy Forest (Paguntalan and Jakosalem 2008). The species is said to prefer hill and montane primary forest (Rabor 1959). If it is correct that the species has not been recorded with certainty since the late 19th century and that it could still persist, it may qualify as Critically Endangered (Possibly Extinct) under criterion C2a(ii) and perhaps criterion D, assuming that it is extremely rare, with a single subpopulation numbering fewer than 250 mature individuals, and perhaps fewer than 50 mature individuals, which is inferred to be in on-going decline owing to habitat loss and degradation.

P. amethystina (as defined following the taxonomic change) is widespread in the Philippines. It has been described as uncommon, which may be partly due to its shyness, but it can be locally very common (Gibbs et al. 2001). It is thought likely to be listed as being of Least Concern, on the basis that it does not 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:

Dutson, G. C. L., Magsalay, P. M. and Timmins, R. J. (1993) The rediscovery of the Cebu Flowerpecker Dicaeum quadricolor, with notes on other forest birds on Cebu, Philippines. Bird Conservation International 3: 235–243.

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.

Hutchinson, R. (2013) Remote Philippines: Mindoro, Sierra Madre, Bohol, Cebu, Negros, Camiguin Sur. Birdtour Asia report.

Paguntalan, L. M. J. and Jakosalem, P. G. (2008) Significant records of birds in forests on Cebu island, central Philippines. Forktail 24: 48–56.

Pedregosa-Hospodarsky, M. (2009) A faunal assessment of North Negros Natural Park (NNNP), Negros Island, Philippines. Report to the Rufford Small Grants Foundation.

Rabor, D. S. (1959) The impact of deforestation on the birds of Cebu, Philippines, with new records for that island. Auk 76: 37–43.

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: Negros Fruit-dove (Ptilinopus arcanus): uplist to Critically Endangered (Possibly Extinct)?
  2. Archived 2014 discussion: White-throated Eared-nightjar (Eurostopodus mystacalis) is being split: list E. exul as Critically Endangered (Possibly Extinct) and E. nigripennis as Vulnerable?
  3. Archived 2011-2012 topics: Ua Pou Monarch (Pomarea mira): reassess as Critically Endangered (Possibly Extinct)?
  4. Archived 2011-2012 topics: Blue-winged Racquet-tail (Prioniturus verticalis): uplist to Critically Endangered?
  5. 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?
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5 Responses to Archived 2014 discussion: Amethyst Brown-dove (Phapitreron amethystina) is being split: list P. maculipectus as Endangered and P. frontalis as Critically Endangered (Possibly Extinct)?

  1. I have additionally observed P. maculipectus at Casa Roro, Negros in January 2003, at Lake Balinsasayao in February 2007 and in the Central Panay Mountains in February 2009. I have not yet seen or heard the species on Mount Kanlaon, Negros and it seems to generally be rare on the island, quite possibly less than 250 individuals.
    I understand from other observers (including Alan Lewis) that the species is vocal and quite common on the Pandan Peninsula in March / April, given that the forest cover here and in the Central Panay Mountains is very extensive, the Panay population is likely to be much higher.

  2. Joe Taylor says:

    Further to the posting of this discussion topic, please note the IUCN guidelines for defining Possibly Extinct taxa:

    “Critically Endangered (Possibly Extinct) taxa are those that are, on the balance of evidence, likely to be extinct, but for which there is a small chance that they may be extant. Hence they should not be listed as Extinct until adequate surveys have failed to record the species and local or unconfirmed reports have been investigated and discounted. ‘Possibly Extinct in the Wild’ correspondingly applies to such species known to survive in captivity.

    Note that ‘Possibly Extinct’ is a tag, and not a new Red List Category.

    Different standards of evidence are required from assessors when deciding to assign a taxon to the Extinct or Critically Endangered (Possibly Extinct) categories. Assignment to the Extinct category requires evidence beyond reasonable doubt that the last individual of the taxon has died. Assignment of the ‘Possibly Extinct’ tag requires that on the balance of evidence, the taxon is likely to be extinct, but there is a small chance that it may be extant. Relevant types of evidence supporting a listing of extinction include (Butchart et al. 2006):
    • For species with recent last records, the decline has been well documented.
    • Severe threatening processes are known to have occurred (e.g., extensive habitat loss, the spread of alien invasive predators, intensive hunting, etc.).
    • The species possesses attributes known to predispose taxa to extinction, e.g. flightlessness (for birds)
    • Recent surveys have been apparently adequate and appropriate to the species’ detectability, but have failed to detect the species.

    Such evidence should be balanced against the following considerations (Butchart et al. 2006):
    • Recent field work has been inadequate (any surveys have been insufficiently intensive/extensive, or inappropriately timed; or the species’ range is inaccessible, remote, unsafe or inadequately known).
    • The species is difficult to detect (it is cryptic, inconspicuous, nocturnal, nomadic, silent or its vocalisations are unknown, identification is difficult, or the species occurs at low densities).
    • There have been reasonably convincing recent local reports or unconfirmed sightings.
    • Suitable habitat (free of introduced predators and pathogens if relevant) remains within the species’ known range, and/or allospecies or congeners may survive despite similar threatening processes.

    Similar considerations apply when assigning a taxon to either the Extinct in the Wild or Critically Endangered (Possibly Extinct in the Wild) categories.”

    Reference:

    IUCN Standards and Petitions Subcommittee (2013) Guidelines for Using the IUCN Red List Categories and Criteria. Version 10.1. Prepared by the Standards and Petitions Subcommittee. Downloadable from http://www.iucnredlist.org/documents/RedListGuidelines.pdf.

  3. 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:

    P. amethystina as Least Concern

    P. maculipectus as Near Threatened under criterion C2a(i)

    P. frontalis as Critically Endangered under criterion C2a(ii)

    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.

  4. 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.

  5. In our recent survey in Northern Negros Natural Park and Southwest Negros IBA we were able to record P. amethystina in several occasions. In NNNP we recorded a few P. a. maculipectus in Victorias City and Calatrava forest at least four individuals in a 15 days survey in a 25 years old logged over mature secondary forest.

    P. a. frontalis was recorded in Alcoy Forest Cebu in 2007 reported by Paguntalan and Jakosalem(2008). I also observed the species in 2011 summer once during my owl study in Alcoy forest. We are still receiving reports of sightings on the species from our field assistant in Alcoy forest in 2012 and 2013. It is quite rare and Alcoy forest is the stronghold of this species.

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