Rationale
(Changed due to Genuine change in status (since first assessment))
The regional population of Bearded Vulture Gypaetus barbatus satisfies the population criterion for regionally Critically Endangered (population size estimated to number less than 250 mature individuals and greater than 90% of mature individuals occurring in a single sub-population). In addition, a decline of 82.8% over the past three generations satisfies the criterion for regionally Critically Endangered, while a quantitative analysis shows the probability of extinction in the wild is at least 50% within the next three generations.
Distribution
The species occurs in Europe, Asia and Africa (Mundy et al. 1992). The subspecies barbatus occurs north of the Tropic of Cancer in Africa, Europe, and Asia while meridionalis occurs only south of the Tropic of Cancer in Ethiopia, East Africa and southern Africa. The regional population is restricted to the highlands of Lesotho and South Africa along the Drakensberg Escarpment of eastern KwaZulu-Natal, north-eastern Eastern Cape and north-eastern Free State. Historically the species has lost c. 40% of its former range in the southern and south-western Western Cape and Eastern Cape provinces (Boshoff et al. 1978, Brown 1991). The species is restricted to Alpine, Sour and mixed grasslands on rugged mountains and escarpments at an altitude of greater than 1 500 m. The birds forage along ridges and valleys in protected areas, but range out over communal and commercial lands. Adult birds appear to avoid areas of human habitation (Mundy et al. 1992). Home ranges of breeding adults did not vary in size between seasons but adults utilised their home range more intensively whilst breeding, moving greater distances during the incubation and chick hatching period (Krüger et al. 2014a). Young birds wander widely, but concentrate in areas of low adult densities, i.e. nursery areas (Mundy et al. 1992, Krüger et al. 2014a).
Population
The global population has been quantified at 1 300-6 700 mature individuals (BirdLife International 2014). There are two isolated populations in Africa, one in Ethiopia (c. 4 000 pairs) and Kenya, Uganda and Tanzania (c. 50 pairs) and an isolated sub-population in the region. The regional population, which is a distinct sub-population, is estimated at 352-390 birds of which c. 200 are mature individuals (Krüger et al. 2014b). The current estimate is based on known nest sites rather than estimated number of nest sites. Confidence in the regional population estimate is high.
Population trend
This species is declining throughout its global range, with the exception of northern Spain, where it has increased since 1986 (BirdLife International 2014). The regional population suffered a decline of nearly 40% in its distribution range from the 1700s until 1969 (Boshoff et al. 1978). In 1991, Brown estimated the breeding population to be in the region of 204 pairs: 122 in Lesotho and 82 in South Africa (Brown 1991a). In the 1990s, Colahan and Esterhuizen (1997) found no breeding pairs in Free State, and Maphisa (1997) noted that sightings in the lowlands of Lesotho were rare and some nest sites were abandoned. The present regional population is estimated at c. 200 mature individuals (Krüger et al. 2014b). Based upon Brown's (1991) and more recently estimate by Krüger et al. (2014c), the decline over the past three generations, or 53 years, is 82.8%. The Vortex (9.9b) population model was used to simulate the extinction process with models predicting a negative growth rate for the population over the next 50 years with a high probability (0.89) of extinction as a result of low survival estimates (particularly for adults; 86%) and reduced productivity (55%). To achieve a positive growth rate, mortality rates would need to be reduced by greater than 50% and productivity increased by greater than 25%. The confidence in this regional population trend estimate is high.
Threats
The primary threat is poisoning with 42% of tracked birds (n=21) being killed due to poison ingestion (Krüger 2014c). Poisoning incidents are mainly indirect, with jackals being the primary target. Electrocution and collisions with power-lines are an additional major threat. Since it is difficult to find carcasses in remote, mountainous terrain, the number of mortalities due to collisions is assumed to be far greater than recorded (SC Krüger pers. obs.). An increase in the electrification of the Lesotho Highlands, in conjunction with current electrification networks of the lowlands of South Africa, is likely to cause collisions to increase (SC Krüger pers. obs.) A further threat is a reduction in food supply caused by a loss of natural ungulates, superior animal husbandry practices and improved animal hygiene (Boshoff et al. 1983). Bearded Vulture mortalities due to gin traps have been recorded in the Free State (Colahan 2004) and Lesotho (Maphisa 1997), but is considered a lesser threat. The intensity of disturbance by people may be increasing because of better access to the interior of Lesotho for the Lesotho Highlands Development Project; many new roads around Katse and Mohale dams allow people and development to move into much of the Lesotho Highlands (Maphisa 1997). Although the threat of direct persecution may not be a current one in South Africa, an increase in the number of firearms in Lesotho may see an increase in incidents (Maphisa 1997). Vultures are an important component in prognostication (e.g. predicting the outcomes of horse races, political elections) in traditional medicine. The skin as well as plumage have been known to be used for ceremonial purposes in southern Africa. The birds are reputed to be used as food in Lesotho (Maphisa 1997). Fires below nesting cliffs, especially if extensive, intensive and of long duration, may influence breeding success.
Conservation
Underway
The Bearded Vulture Task Force coordinates conservation efforts in the region to ensure collaboration between Lesotho and South Africa in implementing actions identified during the Bearded Vulture PHVA workshop held in March 2006. The Bearded Vulture Task Force drafted a Biodiversity Management Plan which was gazetted in May 2014 (Krüger 2013). Current conservation activities include monitoring of nest sites, breeding success, ranging behaviour, population age structure and habitat use. An annual count day, which has a dual purpose of monitoring and awareness raising, is held on the first Saturday of September every year.
Proposed
The action plan section of the Biodiversity Management Plan contains 16 objectives and 107 action steps. A summary of these objectives and action steps is as follows:
Research
* Continued tracking of the population will provide better survival estimates over time which is essential for modelling population trends, avoidance rates of new infrastructure such as wind farms and mortality causes.
* A research project dedicated to exploring lead levels in Bearded and Cape vultures is required to identify the sources of lead contamination in the environment.
* Nuclear markers should be explored to further inform questions on the genetics of the southern African population; such as whether the population is inbred and whether nuclear diversity is as low as mitochondrial diversity was found to be.
* Continued monitoring of the status and demography of the population is essential to evaluate the success of the implementation of the management actions that have been recommended above. Monitoring results should be used in the 5-year review cycle of the management plan to inform future actions as part of an adaptive management approach.
