Lions have been discovered for the first time in an Ethiopian national park, confirming centuries-old stories that the big cats thrived there.

The lions were found in the Alatash National Park in North West Ethiopia, on the Ethiopia-Sudan border in an expedition led by Hans Bauer, a renowned lion conservationist working for Oxford University’s Wildlife Conservation Research Unit. They were also found in Dinder National Park, across the border in eastern Sudan.

“Considering the relative ease with which lion signs were observed, it is likely that they are resident throughout Alatash and Dinder,” Bauer said in a statement. Based on the numbers found, he estimated there could be a population of 100 to 200 lions for the entire ecosystem and more than 50 in Alatash.

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“Due to limited surface water, prey densities are low, and lion densities are likely to be low, we may conservatively assume a density in the range of one to two lions per 100 square kilometers (38.6 square miles),” Bauer said.

Part of the reason the lions have gone undiscovered for so long by outsiders is that the area is rarely visited. Even the International Union for Conservation of Nature only considered Alatash a possible range for the species.

But that changed with Bauer’s expedition, in which they successful obtained camera trap images of lions and identifying lion tracks.

The discovery has been welcomed by conservationists, who have been calling for international efforts to halt the lion's demise. It is listed as vulnerable on the IUCN’s Red List of Endangered species.

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Lion numbers are estimated to have declined 50 percent to 75 percent since 1980 and the species only occupies 8 percent of its historic range across the continent. They were thought to be locally extinct in Sudan.

They are increasingly being killed off to protect humans and livestock and they have lost habitat to agriculture.

Researchers say the next step is alerting government officials in Ethiopia and Sudan about the discovery, so they can embark on possible efforts to conserve these populations and better protected these areas.

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"The confirmation that lions persist in this area is
exciting news,” Born Free’s Chief Executive Adam M. Roberts, whose group funded the expedition, said in a statement.

“With lion numbers in steep decline across most of the African continent, the discovery of previously unconfirmed populations is hugely important – especially in Ethiopia, whose government is a significant conservation ally,” he said. “We need to do all we can to protect these animals and the ecosystem on which they depend, along with all the other remaining lions across Africa, so we can reverse the declines and secure their future.”