Archived 2014 discussion: Silvery Kingfisher (Alcedo argentata) is being split and Indigo-banded Kingfisher (A. cyanopectus) is being split: list A. argentata and A. flumenicola as Vulnerable and A. nigrirostris 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.

Silvery Kingfisher Alcedo argentata is being split into A. argentata and A. flumenicola, and Indigo-banded Kingfisher A. cyanopectus is being split into A. cyanopectus and A. nigrirostris, following the application of criteria set out by Tobias et al. (2010).

Prior to the taxonomic change, A. argentata (BirdLife species factsheet) was listed as Vulnerable under criteria A2c+3c+4c, on the basis that its population was suspected to be undergoing a rapid population decline (30-49% over three generations [c.13 years]) as a result of the loss and decline in the quality of its forested lowland stream habitats.

A. argentata (as defined following the taxonomic change) is found on Basilan, Dinagat, Mindanao and Siargao, whilst A. flumenicola is found on Bohol, Leyte and Samar (Kennedy et al. 2000, del Hoyo et al. 2001). These species favour forested streams and small rivers as well as pools adjacent to forest, predominantly in lowland primary and secondary rainforest, and may tolerate selectively logged forest and plantations near forest (Kennedy et al. 2000, del Hoyo et al. 2001).

It is suggested that both A. argentata and A. flumenicola be listed as Vulnerable under criteria A2c+3c+4c, on the basis that they both could be in rapid population decline (30-49% over three generations [c.13 years]) owing to on-going habitat loss and degradation (through clearance for timber and agricultural expansion), as well as the pollution of streams (see del Hoyo et al. 2001).

Prior to the taxonomic change, A. cyanopectus (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 a very 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). The population trend appeared to be stable, and hence the species did not approach the thresholds for Vulnerable under the population trend criterion (at least a 30% decline over ten years or three generations). The population size has not been quantified, but it was not believed 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).

A. cyanopectus (as defined following the taxonomic change) occurs on Catanduanes, Luzon, Marinduque, Masbate, Mindoro, Polillo, Sibuyan and Ticao, whilst A. nigrirostris is found on Cebu, Negros and Panay, where they are found along forested and scrub-lined streams in the lowlands, foothills and lower montane areas, as well as palm swamps and mangroves (Kennedy et al. 2000, del Hoyo et al. 2001).

Following this taxonomic change, it is suggested that A. cyanopectus be listed as Least Concern, on the basis that it is not thought to approach the thresholds for Vulnerable under any of the IUCN criteria. However, A. nigrirostris may qualify as Near Threatened under criteria A2c+3c+4c, on the basis that it could be undergoing a moderately rapid population decline (approaching 30% over three generations [c.13 years]) owing to on-going habitat loss and degradation.

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

References:

del Hoyo, J., Elliott, A. and Sargatal, J. (2001) Handbook of the birds of the world, Vol 6: Mousebirds to Hornbills. Barcelona, Spain: Lynx Edicions.

Kennedy, R. S., Gonzales, P. C., Dickinson, E. C., Miranda, H. C., Jr. and Fisher, T. H. (2000) A guide to the birds of the Philippines. Oxford, UK: Oxford University Press.

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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3 Responses to Archived 2014 discussion: Silvery Kingfisher (Alcedo argentata) is being split and Indigo-banded Kingfisher (A. cyanopectus) is being split: list A. argentata and A. flumenicola as Vulnerable and A. nigrirostris as Near Threatened?

  1. Desmond Allen says:

    Both Silveries are turning up regularly from a variety of bird photography sites, so they are not desperately rare. Nigrostris has only just started to appear – from Panay. I doubt it is less threatened than Silvery.

  2. 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. argentata as Near Threatened under criteria A2c+3c+4c

    A. flumenicola as Near Threatened under criteria A2c+3c+4c

    A. cyanopectus as Least Concern

    A. nigrirostris as Near Threatened under criteria A2c+3c+4c

    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.

  3. 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.

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