In the wild, African lions are strapping animals. They prowl in prides — the males, with their distinctive manes, defend their territory with thunderous roars; the females, the primary hunters, work together to stalk and ambush their prey. Measuring roughly four feet tall and several hundred pounds, the species is known as “the king of cats.”

But in a set of unnerving images publicized in recent days, five lions are pictured caged, emaciated and dying, held behind bars in a Khartoum park and stripped of all natural stateliness. The photographs were first shared Saturday by Osman Salih, a concerned advocate in the Sudanese capital. Since then, they’ve attracted an audience of thousands, spreading across social media feeds around the world and prompting an online campaign that has adopted the hashtag #SudanAnimalRescue.

But those pleas for help were already too late for at least one lioness, which died Monday, Salih said in a Facebook post that was illustrated with a photo of the animal — eyes closed, frail body curled and ribs visible beneath its patchy fur.

“Seeing these animals caged and be treated this way made my blood boil,” Salih wrote in another post.

Salih watched as some of the lions limped, so malnourished that their spines and hip bones looked like they may poke out of their skin. Others lay on concrete floors, next to rotting meat, as swarms of flies landed on their faces.

The scene was especially hard to see, he said, after he learned about thousands of animals perishing in Australia’s wildfires this month.

It wasn’t immediately clear how the lions ended up in the cages, but they’re located in Al-Qureshi Park, managed by the city government and funded in part by private donors, according to the news service Agence France-Presse, which sent its journalists to see the lions and published more photographs of them.

“Food is not always available, so often we buy it from our own money to feed them,” park manager Essamelddine Hajjar told the outlet.

Officials estimated some of them have lost nearly two-thirds of their body weight. Park administrators have blamed Sudan’s wildlife officials for the lions’ worsening health, Salih said.

“The income of the park for a month is not enough to feed one lion for a week,” he wrote.

Salih said he has worked with a group to contact veterinarians and wildlife specialists, and has arranged meetings with government officials. He wants to offer help — both monetary and manpower — at a time when the country has seen economic crisis and political upheaval.

“The issue is not simply food but most importantly the animals need detailed and special treatment to rid them of infections and issues probably brought about from infested meat and poor diet,” Salih wrote.

But as of Monday, Salih hadn’t yet formed a plan for collecting the donations that many on social media were eagerly offering. Wary of fraudsters, Salih asked anyone interested in giving money to hold off until there is an organized system in place to receive it.

“Too often these situations are exploited and people are scammed,” he wrote in a Sunday post.

In that post, he also said the animal charity and rescue group Four Paws International had agreed to send a team to rehabilitate the animals and train wildlife officials. A spokesperson for the organization said it was “closely monitoring the situation and working hard to get access to the country and the zoo.”

“We are in frequent contact with the responsible national authorities in Sudan,” Martin Bauer, head of public relations for Four Paws, told The Washington Post. “As soon as we get their approval, Four Paws will send a team, consisting of veterinarians and wildlife experts, to Khartoum to provide the urgently needed care for the lions. We hope we can help soon but the final decision for a rescue mission depends on the approval from the national authorities.”

But the problem is probably much larger than Al-Qureshi Park. It’s unclear how many lions are held in captivity in Sudan, but their population is declining worldwide. In the past 21 years, their numbers have dwindled by 43 percent, according to the African Wildlife Foundation. The International Union for Conservation of Nature considers them “vulnerable.”

Salih said there could be parks across Sudan holding lions, and other animals, in similar conditions.

“It is extremely important to note that after this post it has come to our attention that many other parks are in the same poor state,” Salih wrote. “So we hope this initiative can reach out to all wildlife parks and sanctuaries.”

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