Harteman Wildfowl, presented by Jan Harteman
This species has a small population which constitutes a single metapopulation as there is presumed to be movement of individuals within its large range. It is listed as Vulnerable by the IUCN because information from across its range indicates that numbers are in decline owing to a variety of threats.
Trigonoceps occipitalis has an extremely large range in sub-Saharan Africa (from Senegal,Gambia and Guinea-Bissau disjunctly east to Eritrea, Ethiopia and Somalia, and south to easternmost South Africa and Swaziland), where it is uncommon to locally common, but generally widespread outside forested regions (Harrison et al. 1997). It has declined rapidly in parts of West Africa since the early 1940s (P. Hall in litt. 1999, J. M. Thiollay in litt. 2006, 2012), is declining in East Africa (Virani et al. 2011) and in southern Africa is now largely confined to protected areas. In Botswana only four nests were located during gyrocopter surveys of three Important Bird Areas during 2008 and the species has the lowest relative abundance of the vulture species recorded (Hancock 2008), while in Niger there are only four records since 1995, all in the Gadabeji area (J. Brouwer in litt. 2012). The species has probably declined in central Mozambique (Parker 2005a), where the population is estimated at 200 pairs (Parker 2005b). An extrapolated estimate of the global population suggested there were 2,600-4,700 pairs (7,000-12,500 mature individuals) (Mundy et al. 1992).
An estimate of 7,000-12,500 mature individuals was extrapolated from a number of regional estimates. This equates to 10,500-18,750 individuals in total, here rounded to 10,000-20,000 individuals.
More information: http://www.iucnredlist.org/details/106003382/0