The species is assumed to be declining throughout much of its range in the face of a multitude of threats (Boshoff and Anderson 2007). Sixteen known or suspected mortality factors were identified and ranked at an expert workshop with a decrease in the amount of carrion (particularly during chick-rearing), inadvertent poisoning, electrocution on pylons or collision with cables, loss of foraging habitat and unsustainable harvesting for traditional uses considered the most important factors (Mundy et al.
1992, Barnes 2000, Benson 2000, Borello and Borello 2002
, Boshoff and Anderson 2007). The primary threats are currently thought to be contamination of their food supply and possibly a shortage in food supply, negative interactions with human infrastructure and hunting for use in the traditional health industry (BirdLife South Africa in prep.). Further threats include disturbance at colonies, bush encroachment and drowning (Anderson 1999, Borello and Borello 2002
, Bamford et al.
2007). In southern Africa, vultures are caught and consumed for perceived medicinal and psychological benefits (McKean and Botha 2007, Anon. 2008). It is estimated that 160 vultures are sold and that there are 59,000 vulture-part consumption events in eastern South Africa each year, involving an estimated 1,250 hunters, traders and healers. At current harvest levels, the populations of this species in the Eastern Cape, KwaZulu-Natal and Lesotho could become locally extinct within 44-53 years. Should the populations of
White-backed Vultures G. africanus
become depleted first, the resultant increase in hunting pressure on G. coprotheres
could cause a population collapse within the subsequent 12 years (McKean and Botha 2007, Anon. 2008). Extrapolation from a limited study of traditional healers in Maseru, Lesotho, suggests that, conservatively, nearly 7% of the breeding population in that country would be lost annually for such use
(Beilis and Esterhuizen 2005). A study in South Africa found that should current rates of exploitation for market trade continue then the populations in Lesotho, KwaZulu-Natal and Eastern Cape could be exhausted within 54 years (McKean et al
The species suffers mortality from the ingestion of poison left for pests (not vultures) (Diekmann and Strachan 2006) and potentially diclofenac, a non-steroidal anti-inflammatory drug often used for livestock, and which is fatal to Gyps
spp. when ingested at livestock carcasses (Komen 2006,
BirdLife International news www.birdlife.org/news 2007). In 2007, diclofenac, was found to be on sale at a veterinary practice in Tanzania
(BirdLife International news www.birdlife.org/news 2007). In addition, it was reported that in Tanzania, a Brazilian manufacturer has been aggressively marketing the drug for veterinary purposes (C. Bowden in litt
. 2007) and exporting it to 15 African countries
(BirdLife International news www.birdlife.org/news 2007). A single poisoning incident can kill 50-500 birds, making the species susceptible to sudden local declines (M. Diekmann in litt.
2006). The collapse of a key colony in eastern Botswana has been attributed to human disturbance, especially insensitive tourism (Borello and Borello 2002). The ongoing urbanisation around Hartbeespoort Dam and the Magaliesberg Mountains, South Africa, has limited the extent of natural areas for foraging by vultures, perhaps resulting in their reliance on supplementary food at vulture "restaurants"
(Wolter et al
. unpubl.). If such restaurants were closed, vultures might be exposed to unsafe carcasses
(Wolter et al
Poor grassland management in some areas has promoted bush encroachment, making finding carcasses more difficult for vultures (Schultz 2007). There are records of at least 120 individuals (21 incidents) of this species drowning in small farm reservoirs in southern Africa between the early 1970s and late 1990s (Anderson et al
. 1999), although modifications to many reservoirs have now been made (Boshoff et al.
2009). Raptors are thought to drown after attempting to bathe or drink, with mass vulture drownings probably due to the triggering of group behaviour by the actions of one bird (Anderson et al
. 1999). In Magaliesberg a large number of fatalities have been associated with powerline collisions and electrocutions, and this is one of the main factors causing the ongoing decline of the species in South Africa (K. Wolter in litt
. 2007). It is estimated that a minimum of 80 vultures are killed annually by collision with powerlines in Eastern Cape Province (Boshoff et al
. 2011). A controversial wind farm development in Maluti-Drakensberg, Lesotho, an important site for Cape Vulture was given approval in 2014 (Anon. 2014). Even relatively small-scale wind energy developments in the Lesotho Highlands pose a threat to the species (Rushworth and Krger 2014). It is reported that a lack of adult females in the relict Namibian population may have led to four males breeding with G. africanus
, although this is not thought to be a problem across southern Africa (Diekmann and Strachan 2006). Patterns in the contraction of the species's range since the 1950s imply that climate change could be an underlying factor driving its decline through changes in habitats and decreases in prey populations, though further research is required to confirm a link (Simmons and Jenkins 2007).