Namibia’s vultures ‘dying out’

NAMIBIA, renowned for its natural beauty and unique variety of fauna and flora, is on the verge of losing several bird species unless people urgently adopt a more positive role in managing the environment.

A recent trip with the Vultures Namibia Study Group into the Namib-Naukluft Park (NNP) produced irrefutable proof that extinction is looming for several species of the country’s big birds. Seven of the world’s 22 vulture species are found in Namibia.The future of all seven local species is threatened and immediate efforts to preserve their dwindling populations are crucial.The monitoring and ringing of lappet-faced vultures – Africa’s largest vulture – by Vultures Namibia in the NNP is the longest running project of its kind in the country.”It is providing an increasing amount of data, which can be used for wildlife management planning by ornithologists and biodiversity researchers,” explained Peter Bridgeford, co-ordinator of the Vulture Study Group.After its inception in 1991, investigated areas were limited due to vast distances between known breeding zones.Since 2000, an aircraft is being used during the breeding season to conduct an aerial survey during which the exact locations of occupied nests are recorded on GPS.Adult birds, chicks and even eggs can be spotted from the air.”However, it is impossible to differentiate between birds roosting on nests and breeding birds,” said Bridgeford.About a month later, the team returns to the marked locations to measure and ring chicks that have hatched and monitor the growth of previously tagged birds.”This is certainly not a good year for the vulture,” Bridgeford summarised the findings of the 2006 survey, “with only 22 chicks ringed.”The Tsauchab River, ending at Sossusvlei, has shown the biggest decline over the past years, with no breeding birds found for three years now.Ten chicks were ringed there in 1996.Bridgeford ascribed the demise of the breeding colony to increasing tourist vehicles and pleasure flights in the vicinity.Numbers in the Sukses/Tsamvlei and Saagberg/Kamberg areas are down as well and in the Ganab area 14 breeding birds were counted this year compared to the 40 found in 2004.The fact that more birds were ringed on the Tsondab plains, a vast area with only a few scattered trees, than in the Tsondab River and Vlei where the habitat is ideal for breeding, indicates that disturbance by aircraft could be to blame.”Planes on sightseeing trips do not fly over the flat, uninteresting plains, but over the vlei and along the river,” Bridgeford explained.Since 2004, when 52 lappet-faced vulture chicks were ringed in the NNP, numbers have declined rapidly and this year only 22 were ringed.In the past, birds have been marked with a numbered metal ring and five coloured plastic rings.Because it was difficult to observe birds marked in this way and very few sightings were reported, it was decided to use patagial tags.These are numbered, coloured plastic tags fitted to the wing of the bird once it reaches a certain size.FARMERS Vultures and other scavengers are one of the most persecuted groups of animal.Their survival depends largely on farm management techniques aimed at their protection.Indiscriminate and irresponsible use of poison and chemicals on farms is the single biggest threat to their existence.Ten years ago, one farmer in the NNP annihilated ten per cent of the country’s lappet-faced vulture population through a single poisoned carcass, according to information by the Vulture Study Group.Poison also wiped out the entire Cape griffon breeding colonies consisting of thousands of birds.Today, a small population at Waterberg is all that remains in Namibia.Aside from being illegal, the poisoning of carcasses often kills animals other than the targeted predator.The study group reasons that successful farm management is not measured by the number of predators that are killed, but by minimising conflicts between predators and farm animals.Vulture populations are also threatened by drowning in open water reservoirs, electrocution when they fly into power lines, water pollution, disturbance of their nests and the destruction of their natural habitat through bush encroachment and desertification.When a vulture is seen feeding on a carcass, it is often assumed that the bird killed the animal.But vultures are scavengers and not adapted for killing: they are extremely cautious and have weak claws.A bird of prey perched near an ewe that’s giving birth also doesn’t mean the bird is about to kill the newborn.In most, if not all, cases, the bird is waiting to feed on the afterbirth.BENEFITS As carnivores, vultures claim top position in the food chain and their presence is indicative of a healthy environment.Vultures are scavengers that search for food from the sky.Exceptional vision allows them to spot a carcass from thousands of metres away.Vultures are considered to be the cleaners of the environment.They prevent outbreaks of diseases like anthrax and blowfly epidemics because they consume carcasses before they become breeding sites for flies or anthrax spores have time to develop.Seven of the world’s 22 vulture species are found in Namibia.The future of all seven local species is threatened and immediate efforts to preserve their dwindling populations are crucial.The monitoring and ringing of lappet-faced vultures – Africa’s largest vulture – by Vultures Namibia in the NNP is the longest running project of its kind in the country.”It is providing an increasing amount of data, which can be used for wildlife management planning by ornithologists and biodiversity researchers,” explained Peter Bridgeford, co-ordinator of the Vulture Study Group.After its inception in 1991, investigated areas were limited due to vast distances between known breeding zones.Since 2000, an aircraft is being used during the breeding season to conduct an aerial survey during which the exact locations of occupied nests are recorded on GPS.Adult birds, chicks and even eggs can be spotted from the air.”However, it is impossible to differentiate between birds roosting on nests and breeding birds,” said Bridgeford.About a month later, the team returns to the marked locations to measure and ring chicks that have hatched and monitor the growth of previously tagged birds.”This is certainly not a good year for the vulture,” Bridgeford summarised the findings of the 2006 survey, “with only 22 chicks ringed.”The Tsauchab River, ending at Sossusvlei, has shown the biggest decline over the past years, with no breeding birds found for three years now.Ten chicks were ringed there in 1996.Bridgeford ascribed the demise of the breeding colony to increasing tourist vehicles and pleasure flights in the vicinity.Numbers in the Sukses/Tsamvlei and Saagberg/Kamberg areas are down as well and in the Ganab area 14 breeding birds were counted this year compared to the 40 found in 2004.The fact that more birds were ringed on the Tsondab plains, a vast area with only a few scattered trees, than in the Tsondab River and Vlei where the habitat is ideal for breeding, indicates that disturbance by aircraft could be to blame.”Planes on sightseeing trips do not fly over the flat, uninteresting plains, but over the vlei and along the river,” Bridgeford explained.Since 2004, when 52 lappet-faced vulture chicks were ringed in the NNP, numbers have declined rapidly and this year only 22 were ringed.In the past, birds have been marked with a numbered metal ring and five coloured plastic rings.Because it was difficult to observe birds marked in this way and very few sightings were reported, it was decided to use patagial tags.These are numbered, coloured plastic tags fitted to the wing of the bird once it reaches a certain size.FARMERS Vultures and other scavengers are one of the most persecuted groups of animal.Their survival depends largely on farm management techniques aimed at their protection.Indiscriminate and irresponsible use of poison and chemicals on farms is the single biggest threat to their existence.Ten years ago, one farmer in the NNP annihilated ten per cent of the country’s lappet-faced vulture population through a single poisoned carcass, according to information by the Vulture Study Group.Poison also wiped out the entire Cape griffon breeding colonies consisting of thousands of birds.Today, a small population at Waterberg is all that remains in Namibia.Aside from being illegal, the poisoning of carcasses often kills animals other than the targeted predator.The study group reasons that successful farm management is not measured by the number of predators that are killed, but by minimising conflicts between predators and farm animals.Vulture populations are also threatened by drowning in open water reservoirs, electrocution when they fly into power lines, water pollution, disturbance of their nests and the destruction of their natural habitat through bush encroachment and desertification.When a vulture is seen feeding on a carcass, it is often assumed that the bird killed the animal.But vultures are scavengers and not adapted for killing: they are extremely cautious and have weak claws.A bird of prey perched near an ewe that’s giving birth also doesn’t mean the bird is about to kill the newborn.In most, if not all, cases, the bird is waiting to feed on the afterbirth.BENEFITS As carnivores, vultures claim top position in the food chain and their presence is indicative of a healthy environment.Vultures are scavengers that search for food from the sky.Exceptional vision allows them to spot a carcass from thousands of metres away.Vultures are considered to be the cleaners of the environment.They prevent outbreaks of diseases like anthrax and blowfly epidemics because they consume carcasses before they become breeding sites for flies or anthrax spores have time to develop.