The Surprising Fallout From Hunting Top Predators
Posted by Richard Conniff on October 25, 2013
My latest, for TakePart:
Humans have probably been hunting big, scary predators for as long as we have been human, and for the obvious reasons: They are big. They are scary. And they are competition. The fear goes deep in our culture— the Big Bad Wolf was appearing in folk tales in the early middle ages. When I spent a little time on foot in lion habitat a few years ago, the fear felt even more deeply rooted, down somewhere in my gut. Hunting helps restore our precious illusion of control.
Even today, and even among people who may privately loathe the practice, trophy hunting of top predators can seem like a useful tool. The theory is that trophy fees—$10,000 for a lion, say—help pay to protect habitat and keep out poachers. These fees can also provide economic benefits to local communities. That may increase tolerance among people who still live with large, dangerous animals outside their garden gates. Hunting some species may thus serve as the means to increase their numbers— killing predators in order to save them.
But a new study in the journal Biological Conservation asks whether what’s actually happening is the opposite: These methods may be saving large carnivores numerically, but altering their role as apex predators. A top predator that must constantly “look over its shoulder” for fear of human hunters, Andrés Ordiz and his co-authors suggest, may not be a top predator any more. And the effects of that subtle shift can reverberate through entire ecosystems.
As hunters tend to know too well, even white-tailed deer or Canada geese know what to do and where to avoid when hunting season starts. It’s the same for predators, according to the new study: Brown bears tend to shift their daily foraging and resting routines when human hunters arrive. So do lions. Wolves may actually relocate their breeding sites.
The natural ecological function of these predators is to instill “the landscape of fear” in their prey. But they become victims of that landscape instead, spending more time and energy being vigilant, and less out hunting. That means they may not be as effective at controlling numbers of prey species like moose or elk, according to Ordiz and his co-authors. And that can lead in turn to overgrazing and a cascade of other effects on the habitat.
Over the long-term, persistent hunting may also make the predators themselves less big and bad. The long history of hunting and persecution in Europe may be one reason, the study suggests, that European brown bears are not nearly as fierce as grizzlies in North America, though they are the same species, Ursus arctos. “Long-term, human-caused selection may explain the reduced aggression of brown bears towards people, their nocturnal behavior, and their higher investment in reproduction,” the authors write.
When I reached him by phone at the Norwegian University of Life Sciences, Ordiz said that hunters’ preference for large male trophies can have dramatic and destructive social effects, too. When a big brown bear is shot, for instance, infanticide increases over the next two years as other males move in to court the female.
The same thing happens with lions, Craig Packer of the University of Minnesota’s Lion Research Center told me several years ago, when I interviewed him about his research in Tanzania. A young male may take the place of a hunting victim long enough to begin a new litter, said Packer, who is not connected to the study. That new father then needs to stick around to protect those cubs for another two years. But a lot of younger males lack the moxie to hold off challengers. Social upheaval often ensues, with one male after another fathering cubs, but faltering as their protector, and none of the litters ever reaching maturity.
The new paper does not advocate a hunting ban. Controlled, licensed hunting of predators may still be a better alternative than leaving a habitat open to poachers, said Ordiz. (He also noted that his two co-authors have at times been hunters, though of prey species, not predators.) Instead, the paper urges conservationists to start thinking beyond mere predator numbers, to larger ecological effects.
The authors also make recommendations for managing large predators more thoughtfully. Among them: Establish core areas or large-carnivore reserves where predators can be predators, without fear of hunting. In places where hunting is allowed, limit it by space and season to minimize the ecological effects. And end or limit trophy hunting based on traits like the lion’s mane or the Kodiak bear’s size.
These traits—status symbols, social dominance, size, and a little raw ferocity—are the very things that enable these animals to function as big, scary predators in the first place.