The initial deadline for comments on this topic is 10 March 2014, and is therefore later than for most other topics currently under discussion.
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.
Wedge-tailed Sabrewing Campylopterus curvipennis and Long-tailed Sabrewing C. excellens are being lumped as C. curvipennis, following the application of criteria set out by Tobias et al. (2010).
Prior to the taxonomic change, C. curvipennis (BirdLife species factsheet), a resident of forest and secondary growth in southern Mexico, Belize and northern Guatemala (Howell and Webb 1995), was listed as being of Least Concern, on the basis that it was not thought to approach the thresholds for Vulnerable under any of the IUCN Red List criteria. It is, however, noted that its population trend is unknown. Given the on-going threat of habitat clearance for agriculture and development the taxon may well be in decline.
C. excellens (BirdLife species factsheet), a resident of humid evergreen forest and forest edge in southern Mexico (Howell and Webb 1995), was listed as Near Threatened under criteria A2c+3c+4c;B1ab(i,ii,iii,v), on the basis of its moderately small range (30,200 km2), in which habitat is declining, and the suspicion of a moderately rapid population decline. Extensive clearance for cattle-ranching and agriculture has deforested much of the region in which the taxon occurs, and remaining habitat is highly fragmented (Dirzo and García 1992).
On the basis of available information, the newly-defined species may be listed as being of Least Concern, on the basis that it may not approach the thresholds for Vulnerable under any of the IUCN criteria. However, further information is requested on the likely population trend, as the species may warrant listing as Near Threatened if its population trend is thought to approach a decline of 30% over 13 years (estimate of three generations).
Comments are invited and further information would be welcomed.
Dirzo, R. and García, M. C. (1992) Rates of deforestation in Los Tuxtlas, a Neotropical area in southeast Mexico. Conservation Biology 6(1): 84–90.
Howell, S. N. G. and Webb, S. (1995) A guide to the birds of Mexico and northern Central America. 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.