In the weeks since a U.S. dentist killed the beloved Cecil the lion, some experts worried that rival males might infiltrate the pride, oust Cecil’s brother Jericho, and kill off any existing cubs in an attempt to start over fresh with their own genetic line. Concerns for the pride heightened shortly thereafter when Jericho briefly disappeared, and reports spread that he had also been killed.
Luckily, Jericho—who more likely was Cecil’s unrelated domestic partner rather than blood-related—ultimately resurfaced, very much alive, and appears to have resumed his role as head of the pride and protector of the cubs. Some experts have reportedly theorized that enough time has passed now for rogue males not to be much of a threat anymore — so perhaps Cecil’s remaining family will continue on in peace, after all.
But the concern was not altogether unwarranted — and it provides an important window on how human killing of lions, whether for sport or other reasons, can ultimately have disturbing effects well beyond the death of any single individual.
The bottom line, say scientists, is that killing off a mature male lion has a destabilizing effect on lion society, so to speak — and can usher in chaos and more violence.
While many male lions do often live in “coalitions,” or groups of two or more males who govern prides together, smaller coalitions are vulnerable to intrusion by larger ones, according to Craig Packer, director of the University of Minnesota’s Lion Research Center. These intrusions are bad news for babies, as invading males typically kill off any cubs that don’t belong to them.
And “singleton” males, like Jericho is now that Cecil is gone, have an even higher risk of being evicted by roving coalitions, or even just a younger, stronger male. “It’s much harder for a single male to defend himself against a group of young guys than, obviously, a pair,” says Laurence Frank, an associate research zoologist at the University of California, Berkeley and lion conservation expert. This is why conservationists were concerned that Jericho might be overthrown and all the cubs destroyed.
And not only is it sad when a passel of baby animals is killed — there’s a conservation concern associated with this event as well. “If every few years a male is overthrown and all their cubs are killed, that reduces the reproduction rate of the population,” Frank says. It’s not a disaster if this kind of thing happens every now and then (lions “breed like rabbits,” after all, says Frank), but when turnover becomes too high, lion populations can be stunted.
In fact, Packer has published research to this effect. In a 2004 letter in the journal Nature, Packer and his colleagues explained that excessive trophy hunting, which targets males, could cause the death of enough cubs to eventually cause the extinction of a population. These kinds of losses could spell big trouble for lions, which have already declined by at least 90 percent since the 1950s. Recent estimates put total lion numbers at around 35,000 or less.
In the same paper, Packer and his colleagues made some recommendations to improve the sustainability of trophy hunting. In the course of their research, they found that populations were not likely to be significantly affected if hunters limited their kills to males more than five or six years old. This practice lets “younger males have the opportunity to remain resident long enough to rear a cohort of young,” the authors wrote.
An age restriction on lion hunting has since been implemented in some countries, such as Tanzania, Frank says — although he adds that it can sometimes be difficult for hunters to tell the age of a male lion just by looking.
That said, Frank cautions that trophy hunting, even with its risks, is just the tip of the iceberg in terms of human threats to lions. Farmers routinely kill lions in retaliation for the big cats preying on their livestock, and lions also frequently die in snares intended for other animals, such as antelope, he says. And unlike trophy hunting, which typically takes out males, these types of killings are generally indiscriminate.
Still, it seems that worries over Cecil’s young had some grounds beyond just the horror of a baby animal being killed. The case of the cubs is a reminder that good conservation is founded in good science, which tells us the extent to which human activities can be permitted before they start to do real damage. And it’s one more consideration in the increasingly heated debate about the ethics of trophy hunting, which — amidst growing outcry from wildlife lovers — is already in the cross-hairs.