TRACKING BEARDED VULTURES

For the first time in the southern hemisphere, three juvenile Bearded Vultures (Gypaetus barbatus) have been captured and fitted with satellite tracking devices to enable conservationists to determine the extent of their home range and the threats to their survival. The birds, two females and a male, were recently trapped on a farm in the Underberg district and project leader, Sonja Kruger (KZN Wildlife's Ecologist for the Drakensberg area) has already received good data from three birds. The satellite tracking project is a collaboration between KZN Wildlife staff, the Bearded Vulture Task Force of the Birds of Prey Working Group of the Endangered Wildlife Trust and Swiss and Spanish biologists and veterinarians. Through Sonja's contacts with Bearded vulture specialists in Switzerland and Spain, she managed to obtain two satellite transmitters and one GPS solar powered satellite transmitter. In addition several Spanish volunteers came to assist with the capture and fitting of the transmitters. The Spaniards also assisted KZN Wildlife staff to monitor Bearded and Cape vulture nest site activity over the past couple of weeks.

The satellite data shows that the three year old male (blue dots on the map) is ranging widely across Lesotho. The two year old female (red dots on the map) has some very favoured roost spot and makes the occasional long distance trip into unusual areas, whereas the one year old female is restricting her movements to a narrow section of the KZN Drakensberg escarpment. Data from juvenile bearded vulture movement in the northern hemisphere shows that juveniles stay close to their nest during their first year before making large exploratory trips from their second year onwards.

  The satellite tracking programme addresses one of the key actions identified in the Population Habitat and Viability Analysis (PHVA) that was undertaken for the species in 2006. The PHVA used modeling techniques to determine the fate of the southern African bearded vulture population over the next 100 years. The result was the extinction of the species if the juvenile mortality rates were not reduced. It is therefore critical to determine what the threats to juvenile survival are within the range of the species, and hence the implementation of the tracking programme. The satellite data will indicate the movement patterns of the birds and will enable conservationists to identify and address potential threats within this range which may explain the high death rate among young Bearded Vultures. Known threats to the species include collisions with powerlines, poisoning, lack of available food and persecution by some people who think they take livestock. The Bearded Vulture is listed as endangered in the Red Data Book of Birds of South Africa, Lesotho & Swaziland and the breeding population in southern Africa is estimated at less than 150 pairs.

The team also bleached primary feathers on one of the bird's wings (see photo). This will enable EKZN Wildlife staff and the general public to observe the birds until the feathers moult in about two years time. We encourage people to keep a look out for the three birds and report their sightings to gypaetus@kznwildlife.com. Observers should include the date of observation, the location and whether it was the left or right wing feathers that were bleached. Blood samples were also taken from the birds for genetic studies and to determine whether the birds have been exposed to heavy metal poisoning, which is a major threat to the species in Europe.