Black Bustard Eupodotis afra (BirdLife species factsheet) is restricted to the non-grassy, winter rainfall or mixed winter-summer rainfall Fynbos and Succulent Karoo biomes, and the extreme south of the Nama Karoo biome, in a narrow strip along the southern and western coastlines of South Africa (Hofmeyr 2012). It also occurs in semi-arid scrub and dunes with succulent vegetation, and extends into renosterveld scrub and semi-arid karoo (del Hoyo et al. 1996, Hockey et al. 2005). It occurs occasionally in cultivated fields with nearby cover (Hockey et al. 2005). It is currently 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. However, concern has recently been expressed over this species’s status, as there is evidence that it is declining in abundance (per Hofmeyr 2012). Following recent research, it has been recommended that the species be classified as Vulnerable because of past and probable future decreases in its population and because of its susceptibility to on-going land conversion, climate change and possibly increased predation (Hofmeyr 2012). For example, the species is likely to have suffered major habitat loss through the conversion of land to cultivation in the western Cape lowlands (Hockey et al. 2005). The comparison of mapped data from the first and second Southern African Bird Atlas Projects (SABAP1, 1987–1992 and SABAP2, 2007–) indicates that the species declined in abundance in c.80% of its range (Hofmeyr 2012). A negative trend was confirmed by occupancy modelling using the same atlas data, and data from Coordinated Avifaunal Roadcounts indicate declines between 1997 and 2010 in Overberg and Swartland, while it may have increased in the Eastern Cape Karoo region (Hofmeyr 2012). Hofmeyr (2012) argues that these data and analyses constitute convincing evidence that the population of the species declined overall between 1992 and 2010, although the decline may have decelerated from 2008 onwards. Based on these conclusions, Hofmeyr (2012) recommends that the species be considered for listing as Vulnerable under criterion A4, on the basis of a suspected reduction in population size of at least 30% over a three-generation period stretching from the past into the future. This is based on a suspected generation length of at least five years (Hofmeyr 2012); however, BirdLife International estimates the species’s generation length to be c.10.3 years, and thus the three-generation trend period to be c.31 years. Therefore it is possible that the species is in rapid to very rapid decline over a period of three generations (31 years). Additional information is requested on this species, including more input on the severity of threats and the likely population trend over the past 31 years, next 31 years, and/or a window of 31 years stretching from the past into the future. Under criterion A, a decline approaching 30% (typically 25-29%) over three generations would likely make the species eligible for listing as Near Threatened, while a decline of 30-49% would suggest the species should be listed as Vulnerable, and a decline of 50-79% would probably warrant uplisting of the species to Endangered. References: del Hoyo, J., Elliott, A. and Sargatal, J. (1996) Handbook of the birds of the world, Vol 3: Hoatzin to Auks. Barcelona, Spain: Lynx Edicions. Hockey, P. A. R., Dean, W. R. J. and Ryan, P. G. (2005) Roberts birds of southern Africa. 7th edition. Cape Town, South Africa: Trustees of the John Voelcker Bird Book Fund. Hofmeyr, S. (2012) Impacts of environmental change on large terrestrial bird species in South Africa: insights from citizen science data. PhD thesis, University of Cape Town.
Contact the BirdLife Red List Team under redlistteam [at] birdlife [dot] org.