Packer’s reward has been an epic kind of science, a detailed chronicle of the lives and doings of generations of prides: the Plains Pride, the Lost Girls 2, the Transect Truants. Over the decades there have been plagues, births, invasions, feuds and dynasties. When the lions went to war, as they are inclined to do, he was their Homer.
“The scale of the lion study and Craig Packer’s vigor as a scientist are pretty unparalleled,” says Laurence Frank, of the University of California at Berkeley, who studies African lions and hyenas.
One of Packer’s more sensational experiments took aim at a longstanding mystery. A male lion is the only cat with a mane; some scientists believed its function was to protect an animal’s neck during fights. But because lions are the only social felines, Packer thought manes were more likely a message or a status symbol. He asked a Dutch toy company to craft four plush, life-size lions with light and dark manes of different lengths. He named them Lothario, Fabio, Romeo and Julio (as in Iglesias—this was the late 1990s). He attracted lions to the dolls using calls of scavenging hyenas. When they encountered the dummies, female lions almost invariably attempted to seduce the dark-maned ones, while males avoided them, preferring to attack the blonds, particularly those with shorter manes. (Stuffing still protrudes from the haunches of Fabio, a focal point of Lion House décor.)
Consulting their field data, Packer and his colleagues noticed that many males with short manes had suffered from injury or sickness. By contrast, dark-maned males tended to be older than the others, have higher testosterone levels, heal well after wounding and sire more surviving cubs—all of which made them more desirable mates and formidable foes. A mane, it seems, signals vital information about a male’s fighting ability and health to mates and rivals. Newspapers across the globe picked up the finding. “Manely, lady lions look for dark color,” one headline said. “Blonds have less fun in the lion world,” read another.
Lately, Packer’s research has taken on a new dimension. Long a dispassionate student of lion behavior and biology, he has become a champion for the species’ survival. In Tanzania, home to as many as half of all the wild lions on earth, the population is in free fall, having dropped by half since the mid-1990s, to fewer than 10,000. Across Africa, up to one-quarter of the world’s wild lions have vanished in little more than a decade.
The reason for the decline of the king of beasts can be summed up in one word: people. As more Tanzanians take up farming and ranching, they push farther into lion country. Now and then a lion kills a person or livestock; villagers—who once shot only nuisance lions—have started using poisons to wipe out whole prides. It is not a new problem, this interspecies competition for an increasingly scarce resource, but neither is it a simple one. Among other things, Packer and his students are studying how Tanzanians can change their animal husbandry and farming practices to ward off ravenous felines.
Scientists used to believe that prides—groups of a few to more than a dozen related females typically guarded by two or more males—were organized for hunting. Other aspects of the communal lifestyle—the animals’ affinity for napping in giant piles and even nursing each others’ young—were idealized as poignant examples of animal-kingdom altruism. But Packer and his collaborators have found that a pride isn’t formed primarily for catching dinner or sharing parenting chores or cuddling. The lions’ natural world—their behavior, their complex communities, their evolution—is shaped by one brutal, overarching force, what Packer calls “the dreadful enemy.”
The Jua Kali pride lives far out on the Serengeti plains, where the land is the dull color of burlap, and termite mounds rise like small volcanoes. It’s marginal habitat at best, without much shade or cover of any kind. (Jua kali is Swahili for “fierce sun.”) Water holes look more like wallows, prey is scarce and, especially in the dry season, life is not easy for the pride’s four females and two resident males, Hildur and C-Boy.