Kris Everatt was tracking lion prides as part of his conservation research in Mozambique's Limpopo National Park when he came across dozens of dead vultures near a waterhole.
As he walked closer to the waterhole, he saw the mutilated bodies of three lions. Their faces and paws were missing.
"I'd never seen a lion with its head and feet cut off before," said Everatt, the Mozambique program manager for Panthera, a global wild cat conservation organization. "But I knew they were poisoned."
That was more than five years ago. Since then, the number of lions in Limpopo National Park has plunged from 67 to about 10 or less, according to Everatt, who began studying the park's lion population in 2011. Each was poisoned by suspected poachers, and the animals that scavenged their carcasses dropped dead too, he said.
Many of the lions were found with their heads and paws hacked off, while others were only missing their teeth and claws. Some were completely deboned, with just their butchered flesh and skin remaining, Everatt said.
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It's illegal to hunt lions in Limpopo National Park, a protected area of 1 million hectares along Mozambique's western frontier. But just across the border in South Africa, killing captive-bred lions to export their skeletons is perfectly legal -- and increasingly lucrative. The bones are typically shipped to Asia, where they are often falsely advertised as tiger parts in luxury products.
Everatt said he's witnessing the detrimental impact that South Africa's legal lion bone trade is beginning to have on the conservation of wild lion populations, which are already in steep decline across Africa. He said poachers in the region have caught on to the growing market for lion parts, and the iconic big cats are relatively easy to kill by simply lacing a piece of meat with poison.
"There's been this increase in poaching of wild lions where there wasn't before," Everatt told ABC News in a recent telephone interview. "Lions are on the menu now."