When modern humans first started exploring the world, they found a land populated by a whole host of big cat species, many of which then went extinct around 10,000 years ago. It turns out that the forces that drove many Ice Age felines to extinction are still in effect today, and threaten the future of two big cats – the African lion and the Sunda clouded leopard.

It is thought that one of the major factors leading to the decline and eventual extinction of seven ancient felines – four species of sabre-toothed cats, the cave lion, American lion, and American cheetah – is the loss of their prey base. The lack of food, partly driven by our ancestors, coupled with pressure from climate change is thought to have been the main driver of their demise.

Researchers from the University of Sussex and Oxford’s Wildlife Conservation Research Unit decided to see if those same pressures were being exerted on today’s species of big cat. They found that of all modern species, two in particular stuck out. In a paper published in Ecography, they calculated that if all the currently threatened and declining species of prey on which these predators rely were to go extinct, then just 39 percent of the African lion’s prey and 37 percent of the Sunda clouded leopard’s prey would still survive.

“Where prey species have, or are likely to become extinct, this poses a serious risk to the big cat species which feed on them and we now know this is the continuation of an unhappy trend which began during the last Ice Age,” says co-author Dr Chris Sandom in a statement. “We need to buck this Ice Age trend once and for all and to reinforce the urgent need for governments to protect both big cat species and their prey.”

The researchers also modeled how well seven Ice Age big cats would fare if they’d survived the human conflict and climate change that pushed them over the edge 10,000 years ago, and it’s fair to say that it wouldn’t look good. They found that if the cats were still alive today, their prey base would only survive across an average of 25 percent of their historic range, after the majority have gone extinct due to human pressure.  

The study highlights how fragile and interdependent ecosystems are, and the necessity not only to protect the larger, more charismatic species, but the animals on which they rely.