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.
Bearded Helmetcrest Oxypogon guerinii is being split into O. guerinii, O. cyanolaemus, O. lindenii and O. stuebelii, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, O. guerinii (BirdLife species factsheet) 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 criteria.
O. guerinii (as defined following the taxonomic change) occurs in the east Andes of Colombia, south to Cundinamarca. The global population size has not been quantified, but this species is described as locally common, probably at around 3,200-5,200 m, in high mossy páramo where Espeletia species are present (Hilty and Brown 1986, McMullan et al. 2010).
O. cyanolaemus occurs in Santa Marta, north-eastern Colombia, where it is locally common in páramo and adjacent shrubby mountain valleys, probably at around 3,200-5,200 m (Hilty and Brown 1986, McMullan et al. 2010).
O. lindenii occurs in the Andes of north-western Venezuela, in Merida and Trujillo, at 3,600-4,500 m. It is seasonally very common in open páramo, being especially numerous during the rainy season when breeding; at other times of the year it descends to the páramo-forest ecotone near the treeline, with very few remaining in high páramo during the dry months (Hilty 2003).
O. stuebelii occurs in Nevado del Ruiz, central Colombia, where it is locally common, probably at around 3,200-5,200 m, in high mossy páramo where Espeletia species are present (Hilty and Brown 1986, McMullan et al. 2010).
All of these species are inferred to be in decline owing to on-going habitat destruction and degradation caused by over-grazing (del Hoyo et al. 1999), as well as the alteration of páramo caused by burning and the expansion of agriculture and scrubland (WWF 2001).
Both O. cyanolaemus and O. stuebelii could qualify as Vulnerable (or perhaps Endangered) under criterion B1ab(ii,iii,v), if it is shown that they are known to occur at fewer than 11 locations (or their habitat is severely fragmented, i.e. over 50% in patches too small to support viable populations), as they occupy very small ranges (with Extents of Occurrence [EOOs] estimated at c.2,800 km2 and c.4,000 km2 respectively), with on-going declines taking place in the area and quality of suitable habitat.
Both O. guerinii and O. lindenii could qualify as Near Threatened (or perhaps Vulnerable) under criterion B1ab(ii,iii,v), if they are shown to occur at fewer than 20 locations or their habitat is considered at least very fragmented (approaching 50% in patches too small to support viable populations), as they occupy small ranges (with EOOs estimated at c.19,700 km2 and c. 8,600 km2 respectively), in which suitable habitat is in decline and being degraded.
Comments are invited on these suggested categories and further information is requested. In addition to the questions raised above, information is also sought on these species’ likely population sizes (number of mature individuals) and likely subpopulation structure (number of mature individuals in the largest subpopulation or percentage of all mature individuals in a single subpopulation), where subpopulations are defined as geographically or otherwise distinct groups in the population between which there is little demographic or genetic exchange (typically one successful migrant individual per year or less).
del Hoyo, J., Elliott, A. and Sargatal, J. (1999) Handbook of the Birds of the World, vol. 5: Barn-owls to Hummingbirds. Barcelona, Spain: Lynx Edicions.
Hilty, S. L. (2003) Birds of Venezuela. London, UK: A & C Black.
Hilty, S. L. and Brown, W. L. (1986) A guide to the birds of Colombia. Princeton, NJ: Princeton University Press.
McMullan, M., Donegan, T. M. and Quevedo, A. (2010) Field Guide to the Birds of Colombia. Bogotá, Colombia: Fundación ProAves de Colombia.
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.
World Wildlife Fund (2001). Santa Marta páramo (NT1007). [online] Available at: http://web.archive.org/web/20061007183352/http://worldwildlife.org/wildworld/profiles/terrestrial/nt/nt1007_full.html [Accessed 28 September 2012]