Archived 2014 discussion: Grey-faced Woodpecker (Picus canus) is being split: list P. dedemi 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.

Grey-faced Woodpecker Picus canus has been split into P. canus, P. guerini and P. dedemi following the application of criteria set out by Tobias et al. (2010).

Prior to this taxonomic change, P. canus (BirdLife species factsheet) was listed as Least Concern on the basis that it was not thought to approach the thresholds for Vulnerable under any of the IUCN criteria. This species was estimated to have an extremely large range, and hence did not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence of less than 20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline was not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (at least a 30% decline over ten years or three generations). The population size is extremely large, and hence was not thought to approach the thresholds for Vulnerable under the population size criterion (fewer than 10,000 mature individuals with a continuing decline estimated to be at least 10% over ten years or three generations, or with a specified population structure).

P. dedemi is endemic to Sumatra, where it occurs in forest and woodland habitats in montane areas (Winkler et al. 1995, del Hoyo et al. 2002). Deforestation and forest degradation are occurring rapidly in Sumatra, with 35.7% of the primary forest cover in 1990 lost by 2010, and an additional 11% of primary forest cover in 1990 degraded by 2010, although much primary forest in highland areas remains intact (Margono et al. 2012). The species may warrant listing as Near Threatened under criteria A2c+3c+4c, on the basis that it could be in moderately rapid population decline (approaching 30% over three generations [c.17 years]) owing to on-going habitat loss and degradation. The rate of decline is not thought to be more rapid because the species shows some tolerance of habitat modification and fragmentation, and occurs in montane areas, thus it is not exposed to the most rapid rates of deforestation in the region.

P. canus (as defined following the taxonomic change, and incorporating jessoensis) is widely distributed from Western Europe to East Asia, and P. guerini (incorporating all other forms) is widespread in central, eastern and southern China, Hainan and Chinese Taiwan, the northern Indian Subcontinent and throughout much of continental South-East Asia. They are both likely to warrant listing as Least Concern, on the basis that they are not thought to approach the thresholds for Vulnerable under any of the IUCN criteria.

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


del Hoyo, J., Elliott, A. and Sargatal, J. (2002) Handbook of the birds of the world, Vol 7: Jacamars to Woodpeckers. Barcelona, Spain: Lynx Edicions.

Margono, B. A., Turubanova, S., Zhuravleva, I., Potapov, P., Tyukavina, A., Baccini, A., Goetz, S. and Hansen, M. C. (2012) Mapping and monitoring deforestation and forest degradation  in Sumatra (Indonesia) using Landsat time series data sets from 1990 to 2010. Environmental Research Letters 7: 034010. doi:10.1088/1748-9326/7/3/034010

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.

Winkler, H., Christie, D. A. and Nurney, D. (1995) Woodpeckers: a guide to the woodpeckers, piculets and wrynecks of the world. Robertsbridge, U.K.: Pica Press.

This entry was posted in Archive, Asia and tagged . Bookmark the permalink.

8 Responses to Archived 2014 discussion: Grey-faced Woodpecker (Picus canus) is being split: list P. dedemi as Near Threatened?

  1. The recent information on this bird is very limited. Except two photos in OB images from Gunung Leuser National Park, I think we have no other recent information. I think, the status could be Vulnerable rather than Near Threatened.

  2. Any thoughts on which taxon the southern Malay Peninsula population refers to? It is apparently upper montane, and extremely rare – with historical records only from Gunung Tahan in Taman Negara, and the Cameron Highlands. No records from either locality for many years.

    • Joe Taylor says:

      Form robinsoni in the southern Malay Peninsula remains incorporated with other forms to the north under the Tobias et al. (2010) criteria, despite its apparent isolation. Analyses using the criteria suggest species limits between robinsoni and dedemi, but not between robinsoni and its other nearest neighbour hessei.

  3. Joe Taylor says:

    This forum topic was edited on 11 July 2013 to include P. guerini, as this part of the split had previously been omitted in error.

  4. Ding Li Yong says:

    P. dedemi is very overlooked, but the problem for this taxon manifests for many Sumatran species because more birdwatchers inevitably visit Kerinci-Seblat National Park on the summit trail (1,700m asl) and then the Muaro-Sako-Tapan Road (c. 950-1,200 m asl), leaving a wide band of forests in between grossly ‘under-sampled’. The apparent similarity of P. dedemi to the Maroon Woodpecker, which occurs up to submontane elevations add further confusion (J. Eaton in litt.). I am aware of records of P. dedemi in Bukit Tujuh area of KSNP within the late 1990s but this area is usually unvisited by foreign birdwatchers. Other than that, there have been recent sightings in Gunung Leuser National Park, and one recent record (2013) from Mount Sibayak, both in North Sumatra. The species should merit ‘Near-threatened’ at least, until further information becomes available for uplisting.

  5. Pratap Singh says:

    The species distributed in India- P. guerini is quite common and widespread, and there are no apparent threats to the bird and its habitat. Hence qualifies for least concern category.

  6. 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. canus as Least Concern

    P. dedemi as Near Threatened under criteria A2c+3c+4c

    P. guerini 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.

  7. 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.