Grey-banded Babbler (Robsonius sorsogonensis): downlist to Near Threatened?

This discussion was first published as part of the 2013 Red List update, but remains open for comment to enable reassessment in 2014.

BirdLife species factsheet for Grey-banded Babbler

Grey-banded Babbler Robsonius sorsogonensis is currently listed as Vulnerable under B1ab(ii,iii,v) because it has a small range, thought to be found at ten or fewer locations, and its habitat declining both in area and quality as a result of deforestation.

It is found in southern Luzon in the Philippines. However, recent data suggests that it may be present at more localities than previously thought. P. Hosner (in litt. 2012) gathered information on this species’s locality and reported that it is found at more than ten locations, including Sorsogon and Camarines Sur. It has also been suggested that habitat quality may not be important for this species and it may actually prefer scrubby forest, especially where there is a high proportion of bamboo (R. Hutchinson in litt. 2012). Also, this species is very difficult to detect (R. Hutchinson in litt. 2012) and so although it is described as uncommon, it may be more common than suggested by field observations (del Hoyo et al. 2007).

If this information is confirmed, and this species is found at more than ten locations, it would no longer qualify as Vulnerable and would warrant downlisting to Near Threatened under criterion B1ab(ii,iii,v) of the IUCN Red List, on the basis that it approaches the thresholds for Vulnerable.

The term ‘location’ defines a geographically or ecologically distinct area in which a single threatening event can rapidly affect all individuals of the taxon present. The size of the location depends on the area covered by the threatening event and may include part of one or many subpopulations. Where a taxon is affected by more than one threatening event, location should be defined by considering the most serious plausible threat. (IUCN 2001). For example, where the most serious plausible threat is habitat loss, a location is an area where a single development project can eliminate or severely reduce the population. Where the most serious plausible threat is volcanic eruption, hurricane, tsunami, frequent flood or fire, locations may be defined by the previous or predicted extent of lava flows, storm paths, inundation, fire paths, etc.

Information on this species’s distribution, population size and trends is welcome.


del Hoyo, J., Elliott, A. and Christie, D. (2007) Handbook of the Birds of the World, vol. 12: Picathartes to Tits and Chickadees. Lynx Edicions: Barcelona, Spain.

Related posts:

  1. Rusty Laughingthrush (Garrulax poecilorhynchus): uplist to Near Threatened or Vulnerable?
  2. Archived 2012-2013 topics: Black-throated Babbler (Stachyris nigricollis) and Fluffy-backed Tit-babbler (Macronous ptilosus): downlist both to Least Concern?
  3. Archived 2010-2011 topics: Newly-split Malayan Banded Pitta (Pitta irena), Bornean Banded Pitta (P. schwaneri) and Javan Banded Pitta (P. guajana): list all as Least Concern?
  4. Archived 2011-2012 topics: Short-tailed Scimitar-babbler (Jabouilleia danjoui): downlist to Least Concern?
  5. Archived 2011-2012 topics: Nonggang Babbler (Stachyris nonggangensis): uplist to Vulnerable?
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2 Responses to Grey-banded Babbler (Robsonius sorsogonensis): downlist to Near Threatened?

  1. Andy Symes says:

    Preliminary proposals

    Based on available information, our preliminary proposal for the 2014 Red List is to pend the decision on Grey-banded Babbler Robsonius sorsogonensis and keep this discussion open until early 2015, while leaving the current Red List category unchanged in the 2014 update.

    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 categorisation to be put forward to IUCN

    Following further review, there has been no change to our preliminary proposal for the 2014 Red List status of this species.

    This discussion will remain open for further comments and information until early 2015, and the current Red List category will remain unchanged in 2014.

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