This discussion was first published as part of the 2016 Red List update. At the time a decision regarding its status was pended, but to enable potential reassessment of this species as part of the 2017 Red List update this post remained open and the date of posting was updated.
BirdLife species factsheet for Bush Blackcap: http://www.birdlife.org/datazone/species/factsheet/22716650
Sylvia nigricapillus ranges from the north Eastern Cape, through KwaZulu-Natal, the eastern Free State and Mpumalanga in eastern South Africa, as well as western Swaziland. It is generally uncommon to fairly common (del Hoyo et al. 2007), within a small range. The South African population has been estimated at 1,500-5,000 individuals, with 500-1,000 estimated to be in reserves. Swaziland is thought to hold a resident breeding population of 40 individuals. The species is currently listed as Near Threatened as it has a small population but was not confirmed to be undergoing continuing declines.
In the 2015 Eskom Red Data Book of Birds of South Africa, Lesotho and Swaziland (Taylor et al. 2015) this species is listed as having a population size of 1,500-3,000 individuals. They list its area of occupancy as having decreased by 34% to 37, 200km2 between Southern African Bird Atlas Projects (SABAP1 & 2) (SABAP 1 data mainly 1987-1993; SABAP 2 data 2007-2014), but this may be an overestimate and the range may in fact be as small as 744km2. Taylor et al. state that it has experienced a decline of 30% over the past 15 years and so list it as Vulnerable under criteria A2bc.
Other recent literature using SABAP data give range declines of 11% (Cooper 2015) or 6% (Lee et al. in press), with even a possible core range increase of 11% (Lee et al. in press).
We therefore request any further information and comments on this possible trends occurring within this species. Confirmation of the trends presented by Taylor et al. (2015) would likely qualify the species for uplisting to globally Vulnerable under criterion A2bc because of a suspected population decline of ≥30% in the past 3 generations based on an index of abundance appropriate to the taxon, and a decline in the area of occupancy, extent of occurrence and/or habitat quality.
Cooper, T. J. G. 2015. The effects of land use changes on the distribution of forest dependent bird species in South Africa. Master’s thesis, Stellenbosch University
del Hoyo, J.; Elliott, A.; Christie, D. 2007. Handbook of the Birds of the World, vol. 12: Picathartes to Tits and Chickadees. Lynx Edicions, Barcelona, Spain
Lee, A.; Barnard, P.; Altwegg, R. (in press) Estimating conservation metrics from atlas data: the case of southern African endemic birds. Bird Conservation International.
Taylor, M. R.; Peacock, F.; Wanless, R. M. 2015. The 2015 Eskom Red Data Book of Birds of South Africa, Lesotho and Swaziland. BirdLife South Africa, Johannesburg.