This is part of a consultation on the Red List implications of extensive changes to BirdLife’s taxonomy for passerines
Lynx Edicions and BirdLife International will soon publish the second volume of 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 2 of the checklist (for passerines) will begin to be incorporated into the 2016 Red List update, with the remainder 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.
Orchard Oriole Icterus spurius is being split into I. spurius and I. fuertesi, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, I. spurius was listed as Least Concern, on the basis that it did not approach the threshold for Vulnerable under any criterion. I. spurius (as now defined following the taxonomic change) is still not thought to approach the threshold for Vulnerable under any criterion and so would warrant listing as Least Concern.
I. fuertesi is believed to breed in open areas around agricultural land, secondary vegetation, urban areas including gardens and dense scrub on the Caribbean coast of Mexico (Howell and Webb 1995, Tobón-Sampedro and Rojas-Soto 2015, Fraga 2016). Its non-breeding distribution is still not certain (Tobón-Sampedro and Rojas-Soto 2015), and may involve movements to the Pacific coast of Mexico or a southwards shift towards the Guatemala border (Tobón-Sampedro and Rojas-Soto 2015; see also records from ebird website http://ebird.org/ebird/map/). Tobón-Sampedro and Rojas-Soto (2015) modelled potential winter distributions, which could be fairly restricted, but this was derived from data from only 5 winter sites, while other winter records were not included in analyses (see Tobón-Sampedro and Rojas-Soto 2015 for reasoning). While the picture over movements is starting to become clearer thanks to the work of Tobón-Sampedro and Rojas-Soto (2015), the full picture is not clear over its possible distribution and so a Red List analysis based solely on range size should not be used.
The species has been described as uncommon to common, and perhaps (at least historically) increasing in number (Graber and Graber 1954, Fraga 2016). Therefore this species may not approach the threshold for Vulnerable under any other criteria. We request any potential further information, especially regarding the non-breeding distribution of this species, but in the absence of this information this species would likely warrant listing as Least Concern.
Fraga, R. 2016. Fuertes’s Oriole (Icterus fuertesi). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/62267 on 6 October 2016).
Graber, R.R. and Graber, J.W. (1954) Comparative notes on Fuertes and Orchard Orioles. Condor 56: 274-282.
Howell, S.N.G. and Webb, S. 1995. A Guide to the Birds of Mexico and Northern Central America. Oxford University Press, New York.
Tobón-Sampedro, A. and Rojas-Soto, O. R. 2015. The geographic and seasonal potential distribution of the little known Fuertes’s Oriole Icterus fuertesi. Bird Conservation International 25(4): 489–502.
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.