For decades, Dr. Packer ran the Serengeti Lion Project in Tanzania and lobbied for greater oversight of the country’s hunting industry. His tenure ended in 2014 when Tanzanian wildlife officials barred him from the country, citing derogatory statements he made about the industry in an email. Months later, the killing of a beloved lion named Cecil by an American tourist in Zimbabwe set off a firestorm over the ethics of big-game hunting. But while the debate that ensued attracted global attention, it failed to address a fundamental challenge: If African wildlife can’t pay its own way, who will?

The answer, increasingly, is what’s known as “collaborative management.” More and more, African wildlife authorities are partnering with nonprofit organizations to secure ecologically valuable landscapes. And as these public-private ventures have in recent years proliferated across the continent, they’ve channeled philanthropic capital to conservation efforts on an extraordinary scale.

The use of philanthropy to support conservation is hardly a new phenomenon; many of America’s most iconic protected areas owe their existence, in part or in whole, to gifts of land and money. But while governance and operations have long been the exclusive domain of the state, new collaborative management models take a hybrid approach, using private resources and technical expertise to protect and expand lands held by the government while restoring native habitat and rebuilding populations of wildlife.

One prominent example of such a philanthropy is the American Prairie Reserve, a nonprofit that raises private funds to stitch together more than three million acres of existing public lands across Montana’s northern Great Plains. There’s also Tompkins Conservation, a group founded by the American philanthropist Kristine McDivitt Tompkins and her husband, Douglas, to create national parks and restore ecosystems in Chile and Argentina. The group’s donation of more than a million acres of restored conservation land to the government of Chile prompted the creation last year of five new national parks and the expansion of three others.

Nowhere are the stakes higher, though, than in Africa, home to the world’s largest intact ecosystems, close to a quarter of global biodiversity and some of the planet’s highest rates of human population growth.

“People all over the world enjoy African wildlife, but for those who live next to these animals, it’s a daily challenge,” I was told by Mujon Baghai, an independent researcher and the leading author of a recent study of protected areas in Africa. “Their crops get raided, their livestock may get eaten, and they forgo opportunities to use the land in other ways,” she said. “The international community has a responsibility to help preserve these wild places and to do in ways that ensure local communities benefit.”

In the study, Ms. Baghai and her colleagues examined the strengths and weaknesses of various partnership models. “By far the most successful are those that are long-term,” she said. “Projects like Gorongosa in Mozambique and, on a much larger scale, African Parks.”