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.
Stripe-headed Brush-finch Arremon torquatus is being split into A. torquatus, A. assimilis, A. atricapillus, A. basilicus, A. costaricensis, A. perijanus, A. phaeopleurus and A. phygas, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, A. torquatus was listed as Least Concern, on the basis that it did not approach the threshold for Vulnerable under any criterion. A. torquatus (as now defined following the taxonomic change), A. assimilis, A. atricapillus, A. costaricensis and A. phaeopleurus all do not appear to approach the threshold for Vulnerable under any criterion and so it is proposed that they be listed as Least Concern.
Arremon basilicus is found only in the Santa Marta Mountains of northern Colombia, in undergrowth and forest edges (Jaramillo 2016). It is locally common, and there is no evidence for any declines (Jaramillo 2016). It is likely not thought to meet the threshold for Vulnerable any criterion, but given its small range is increasingly being destroyed by the expansion of illegal agricultural, logging and burning (Renjifo et al. 2002), if there is any evidence that its range is being fragmented or severely fragmented it may qualify as Near Threatened or Vulnerable under criterion B1ab(ii,iii).
A. perijanus is found only in the Perija Mountains on the border of Colombia and Venezuela, in forest edge and border habitat between 700 and 1,900 m (see Jaramillo et al. 2016). Lower-elevation habitat (below 2,000 m) is under threat from a range of processes; including colonisation, the cultivation of narcotics, ranching and mineral exploitation – which are aided by the roads approaching the Colombian side – [C. J. Sharpein litt.1997, 2000, A. Viloria per J. Fjeldså in litt. 1998, Sharpe and Lentino 2008a]. This species may be able to cope with such some habitat disturbance, given its preference for edge habitats. However, given the great extent of the habitat conversion and clearance, its population may be declining and becoming fragmented, though we request any further information regarding this. This would mean that the species at least warrants listing as Near Threatened under criterion B1ab(i,ii,iii,v). However, if any evidence exists to show this species may be severely fragmented (see IUCN 2001, 2012) this species may qualify to be listed as at least Vulnerable under the same criterion.
A. phygas is found only in a few localities in the extreme north-east of Venezuela (Jaramillo and Sharpe 2016) in the Turimiquire Massif (Quebrada Bonita andCerro Peonía), and Paria Peninsula (Cerro Negro in Cordillera de Caripe, and Cerro Humo) (Phelps and Phelps 1950). It inhabits the undergrowth of montane forest, and is occasionally found at forest borders and edges (Jaramillo and Sharpe 2016) and it is uncommon to rare throughout its range (Jaramillo and Sharpe 2016); though the population size has not been quantified. Within its range there has been widespread clearance for agriculture and pasture, and even in El Guácharo National Park there has been clearance, repeated burning and understorey removal (Boesman and Curson 1995, Sharpe and Lentino 2008b). The slopes of Cerro Negro have been extensively cleared, with the more obvious forest patches actually shade-coffee plantations (Boesman and Curson 1995), and on Cerro Humo, increases in agriculture since the mid- to late 1980s, have led to uncontrolled burning and forest degradation. However, in the Turimiquire Massif while there has been conversion to plantations, extensive forested areas may still be present (e.g. Colvee 1999, Sharpe in litt. 2011). Overall, however, the population is suspected to be in decline and fragmented in line with habitat loss. Therefore, given its very small range, and its known presence from only a very small number of localities, this species likely qualifies at least as Vulnerable under criterion B1ab(i,ii,iii,v), and possibly Endangered pending further information regarding its Extent of Occurrence.
Comments are invited on these proposed categories and further information would be welcomed.
Boesman, P. and Curson, J. 1995. Grey-headed Warbler Basileuterus griseiceps in danger of extinction? Cotinga: 35-39.
Colvee, J. N. 1999. Observaciones preliminares sobre el estado actual del hábitat de cuatro especies de aves en la Serrana de Turimiquire, Edos. Monagas, Anzoátegui y Sucre de Venezuela.
IUCN. 2001. IUCN Red List Categories and Criteria: Version 3.1. Gland, Switzerland and Cambridge, UK: IUCN Species Survival Commission.
IUCN. 2012. Guidelines for Application of IUCN Red List Criteria at Regional and National Levels: Version 4.0. Gland, Switzerland and Cambridge, UK: IUCN.
Jaramillo, A. 2016. Bangs’s Brush-finch (Arremon basilicus). 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/61970 on 4 October 2016).
Jaramillo, A. and Sharpe, C.J. 2016. Paria Brush-finch (Arremon phygas). 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/61974 on 4 October 2016).
Jaramillo, A., Sharpe, C.J. and Boesman, P. 2016. Perija Brush-finch (Arremon perijanus). 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 fromhttp://www.hbw.com/node/61971 on 4 October 2016).
Phelps, W.H. & Phelps, W.H. Jr. (1950) Lista de las Aves de Venezuela con su Distribución. Parte 2. Passeriformes. Boletín de la Sociedad Venezolana de Ciencias Naturales 12(75). 427 pp.
Renjifo, L. M., Franco-Maya, A. M., Amaya-Espinel, J. D., Kattan, G. H., and López-Lans, B. 2002. Libro rojo de aves de Colombia. Instituto de Investigación de Recursos Biológicos Alexander von Humboldt y Ministerio del Medio Ambiente, Bogot, Colombia.
Sharpe, C.J. and Lentino, M. 2008a. Piscuiz de Perijá Schizoeaca perijana. In: Rodríguez, J.P. and Rojas-Suárez, F. (eds), Libro Rojo de la fauna Venezolana. Tercera Edición, pp. 150. Provita & Shell Venezuela, S.A., Caracas, Venezuela.
Sharpe, C.J. and Lentino, M. 2008b. Fafao gargantibalnco Premnoplex tatei. In: Rodríguez, J.P. and Rojas-Suárez, F. (eds), Libro Rojo de la fauna Venezolana. Tercera Edición, pp. 149. Provita & Shell Venezuela, S.A., Caracas, Venezuela.
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.