Blue-crowned Racquet-tail (Prioniturus discurus) is being split: list P. mindorensis as Vulnerable?

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 2013 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.

Blue-crowned Racquet-tail Prioniturus discurus is being split into P. discurus and P. mindorensis, following the application of criteria set out by Tobias et al. (2010).

Prior to this taxonomic change, P. discurus (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.

P. mindorensis is endemic to Mindoro, where it occupies a variety of forested habitats, including substantially modified areas such as orchards and plantations (del Hoyo et al. 1997, Juniper and Parr 1998). It is suggested that it qualifies as Vulnerable under criterion C2a(ii), on the basis that it may have small population – numbering fewer than 10,000 mature individuals and probably forming a single subpopulation – which is inferred to be in on-going decline owing to the continued loss and degradation of optimal habitat and significant trapping pressure (Juniper and Parr 1998). Listing of this taxon as Vulnerable was also tentatively suggested by Dutson et al. (1992).

P. discurus (as defined following the taxonomic change) occurs on most islands in the Philippines and occupies a variety of habitats, including humid primary and secondary forest, mangroves, plantations and cultivation (del Hoyo et al. 1997, Juniper and Parr 1998). In the pre-split BirdLife species factsheet, the population is considered to be stable, although it could be in slow to moderate decline (<25% over three generations, estimated to be c.16 years), owing to deforestation and limited trapping pressure, and is likely to number over 10,000 individuals (Juniper and Parr 1998, Forshaw 2006). On this basis, it is likely to be listed as being of Least Concern, on the basis that it is 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.

References:

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.

Dutson, G. C. L., Evans, T. D., Brooks, T. M., Asane, D. C., Timmins, R. J. and Toledo, A. (1992) Conservation status of birds on Mindoro, Philippines. Bird Conservation International 2: 303-325.

Forshaw, J. M. (2006) Parrots of the world: an identification guide. Princeton, NJ and Oxford, UK: Princeton University Press.

Juniper, T. and Parr, M. (1998) Parrots: a guide to the parrots of the world. Robertsbridge, UK: Pica 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.

Related posts:

1. Archived 2011-2012 topics: Blue-winged Racquet-tail (Prioniturus verticalis): uplist to Critically Endangered?
2. Blue-rumped Parrot (Psittinus cyanurus) is being split: list P. abbotti as Vulnerable and P. cyanurus as Near Threatened?
3. Rainbow Lorikeet (Trichoglossus haematodus) is being split: list T. rosenbergii as Vulnerable and both T. weberi and T. forsteni as Near Threatened?
4. Philippine Hawk-owl (Ninox philippensis) is being split: list N. leventisi and N. rumseyi as Endangered, N. reyi and N. mindorensis as Vulnerable, and N. spilonota and N. philippensis as Near Threatened?
5. Blue-banded Kingfisher (Alcedo euryzona) is being split: list A. euryzona as Critically Endangered and A. peninsulae as Vulnerable?