BirdLife species factsheet for White-bellied Barbet: http://datazone.birdlife.org/species/factsheet/white-bellied-barbet-lybius-leucogaster
White-bellied Barbet, Lybius leucogaster, is currently listed as Least Concern on the basis that it was thought that it did not approach the threshold for Vulnerable under any criterion. This species is thought to occur only in the highlands of south-western Angola, and requires woodland habitats (del Hoyo et al. 2016). However, within its range large areas have been deforested and forest loss continues (Hansen et al. 2013; del Hoyo et al. 2016). There has been a lack of any records since the 1970s (M. Mills in litt. 2014), but it is thought that the species will eventually be found in suitable habitat around the Serra da Neve and at the bottom of the Angolan escarpment to the west of Lubango (del Hoyo et al. 2016). However, the species likely warrants listing under a higher threat category than Least Concern.
Using low population density estimates for congeners (given the lack of records) and assuming only a proportion of its range is occupied would give a population size estimate in the range of 2,500-9,999 mature individuals. However, the paucity of remaining forest cover in its range and the fact that it has not been recorded for so long means that the population size estimate may be even lower than this and may instead fall below 2,500 mature individuals. The continued loss of forest within L. leucogaster’s range means that any possible remaining population is likely in decline, and so this species qualifies at least as Vulnerable under criterion C2a(ii), and potentially as Endangered under the same criterion pending further comments regarding population size estimates.
Any further comments and information regarding this proposed uplisting are welcomed.
del Hoyo, J., Collar, N. & Kirwan, G.M. (2016). White-bellied Barbet (Lybius leucogaster). 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/467451 on 22 December 2016).
Hansen, M. C., P. V. Potapov, R. Moore, M. Hancher, S. A. Turubanova, A. Tyukavina, D. Thau, S. V. Stehman, S. J. Goetz, T. R. Loveland, A. Kommareddy, A. Egorov, L. Chini, C. O. Justice, and J. R. G. Townshend. 2013. High-Resolution Global Maps of 21st-Century Forest Cover Change. Science 342: 850–53. Data available on-line from: http://earthenginepartners.appspot.com/science-2013-global-forest. Accessed through Global Forest Watch on [22/12/2016]. www.globalforestwatch.org.