Endangered white-backed vultures across southern Africa often shun national parks, preferring to forage further afield where they can encounter dead cattle or even poisoned carcasses intended to control other carnivores such as jackals, researchers at Durham University reported.
The problem is not limited to Africa, the researchers said. In India, several vulture species are on the verge of extinction due to accidental poisoning from cattle carcasses containing anti-inflammatory drugs administered by farmers.
There is concern such drugs, non-lethal to cattle yet fatal to vultures, could become more widely used in Africa, they said.
Vultures prefer to feed in savannah grassland habitats and away from other competing carnivores such as lions, and will go to considerable lengths to find food, Durham biologist Stephen Wills said.
"We found that young vultures travel much further than we ever imagined to find food, sometimes moving more than 220 kilometers (135 miles) a day," he said. "Individuals moved through up to five countries over a period of 200 days, emphasizing the need for conservation collaboration among countries to protect this species."
The researchers tracked six immature African white-backed vultures using GPS tracking collars.
"In the past, we believed that protecting nature reserves and conservancies was the way to go but tracking devices show that vultures are spending very little time in protected areas, and this makes conserving these birds much more difficult," said Kerri Wolter of the vulture conservation program VulPro.
"Given the distances that vultures forage, we cannot conserve these birds 'in-country' but have to work together with conservation organization's, governments and neighboring countries to safeguard vulture species across the globe."