Lions are a keystone species in their ecosystem
The elimination of top predators destabilizes ecosystems, setting off far-reaching and unpredictable reactions along the food chain.
BY Karyl Carmignani
Photography by Ken Bohn
Lions have been padding across the savanna for centuries, vying for mates, raising cubs, and cooperatively chasing down prey. The lions’ finely tuned dance with their habitat has helped keep the complex ecosystem in balance: apex predators control hoofed animal populations, as well as keeping them wary and on the move, thus not overgrazing any one area. Countless other creatures rely on the lions’ leftovers to survive. With their broad habitat tolerance, lions once roamed across most of Africa, and even lived in Greece, the Middle East, and into southern India. They are now found only south of the Sahara Desert and in a small population surviving in India’s Gir Forest.
Taxonomists have found that the lion’s closest living relatives are the jaguar and leopard.
Lion Panthera leo populations declined by about 43 percent between 1993 and 2014, according to the IUCN Red List. A bloody combination of forces has led to this drastic decline: indiscriminate killing of the big cats in retaliation for taking livestock or human life, and the depletion of the lion’s prey base (large, wild herbivores), animals that are often consumed by burgeoning human populations. Compounding the pressure is the poaching of the cats for their body parts, which are illegally traded for use in Asian folk remedies. Poorly regulated trophy hunting can also pose a threat by removing the “biggest and baddest” male lions from an area, which can disrupt or destroy lion prides. As human populations have increased, so have threats to lions, including habitat loss. The lion has disappeared from about 80 percent of its African range; estimates say less than 20,000 wild lions survive in Africa today.
Like most conservation issues, saving lions is a complex, multilayered, cooperative proposition. While it is easy for “city slickers” to shake our fists at locals who kill these clever and ecologically important carnivores, the fact is, the cats can be a menacing threat to the livelihood and families of people who share the habitat. In southeastern Tanzania alone, about 400 lion-related human deaths were documented between 1997 and 2007. For pastoralists, who rely on the meat, milk, and blood of their cattle and goats to survive, lions preying on their livestock can have a huge adverse effect, ranging from $290 to $370 per owner each year. Nomadic pastoralists, often children, can inadvertently walk into lion territory as they herd their flocks to fresh pastures in search of grazing, alongside wild herbivores.
To head off a family’s economic or personal disaster, “lions are persecuted intensely in livestock areas across Africa,” according to the IUCN. This includes tainting cattle carcasses with poison, which lions often return to after a bout of feeding. The lions then suffer a prolonged, excruciating death, as do many other animals in the food chain, including scavengers like hyenas and vultures.
But lions serve a keystone role in their habitats, keeping hoofed animal populations of zebra, buffalo, giraffe, and antelope in check and mobile. “Without lions as the apex predator, the entire ecosystem is thrown out of balance. This causes a cascading effect that results in numerous other extinctions or invasions by nonnative species,” explained Carmi Penny, San Diego Zoo Global director of collections husbandry science and curator of mammals. People who live in and near lion habitat—and who often compete with native hoofed animals because their grazing livestock push out these prey species—will feel the crash of lion populations first. Left unchecked, native animals will overgraze vegetation, leaving little for livestock, and resulting in hardship for the local people.
Helping People Help Lions
In order to change the dynamic and prevent this catastrophe, San Diego Zoo Global provides funds to two boots-on-the-ground partner organizations that work to protect habitat and wildlife diversity: Ewaso Lions and the Northern Rangelands Trust. To be successful, strategies to save lions (and other wildlife) must respect and incorporate the needs of local people. By showing that predators like lions are critical to the health and diversity of the ecosystem, these community-based conservancies benefit both humans and animals. They foster understanding that the occasional loss of a cow or goat is acceptable, because of the greater good to the community by having lions present. At the same time, these partner organizations are also helping to develop programs to better control and protect livestock. While human-lion conflict may continue to occur, through education and community support, people can learn to live with lions, and stronger, healthier ecosystems will prevail.