Study by: Team of Biologists, University of Minnesota.
Declaration of interest: None
http://news.sciencemag.org/sciencenow/2 ... fires.html
African lions are one step away from becoming an endangered species, and a measure designed to preserve them is to blame. A new study suggests that hunters who pay to shoot the animals are killing too many of the big cats.
Seventy years ago, the kings of the jungle numbered 450,000. Now the lion population has dwindled to less than a tenth of that. In the 1980s and 1990s, African nations started to think an old practice might hold the solution to saving the lion: trophy hunting. They hoped that by allowing rich game-chasers to shoot a few animals, landowners would have an incentive to conserve lion habitats and keep the species alive while boosting their local economies. In the meantime, it became conventional wisdom to blame the decline on factors such as conversion of lion habitat for agriculture, disease, and killings by locals upset over lion attacks on people or livestock. But the newest research, to be published in an upcoming issue of Conservation Biology, shows that at least in Tanzania—home to more lions than any other country—that isn’t the case.
Led by Craig Packer of the University of Minnesota, Twin Cities, a team of biologists took a closer look at the diminishing lion populations in Tanzania over the last decade. The researchers analyzed the amount of game brought back by hunters from 21-day safaris, the only legal way to hunt lions in the East African nation. They discovered that from 1996 to 2008, the number of lions hunters bagged in Tanzania decreased by half. It’s not that hunters are scarce: Sales of the wilderness treks have risen by 60% since 1998. And the hunters probably aren’t deliberately shooting fewer animals either, according to geographer Brian Child of the University of Florida, Gainesville, who was not part of the study. “In general, if they’re paying a lot of money, they’re going to be hunting as hard as they can,” Child says.
This leaves only one reason the hunters are bringing in less game: There’s less game out there to shoot.
Packer’s team looked at several explanations for the decline. Expanding agriculture, disease, and retaliatory killings might all play a role, but those threats paled in comparison to recreational hunting, according to the team’s analysis. Shooting for sport was responsible for 92% of hunters’ reduced success.
“I would not have guessed that 92% of the population trend would be explained by trophy hunting, and these other factors would be so weak,” says Scott Creel, an ecologist at Montana State University, Bozeman, who was also not part of Packer’s team.
The numbers are falling in areas where hunting is banned as well. Populations decreased in three out of five protected areas analyzed, including two national parks. Although the reduction in one region (Ngorongoro Conservation Area) could be chalked up to an epidemic and some unfortunate confrontations with herders, those problems also existed in the few areas that saw their lion numbers rise or stay the same. That rules out sickness or retaliatory killing as reasons for the downward trend. According to Packer, trophy hunting can even harm lions that live in places where it’s forbidden, because lions don’t stay put. “These parks are not fenced, and so the lions can pass freely inside and outside the park,” he says. “And if they are outside the park during hunting season, they may be shot.”
Packer suspects that hunters have been overexploiting the lions. Although he acknowledges that the idea of hunting for conservation may work in theory, “there’s no point in providing the animal with economic value and then over-hunting them.”
“But there’s a silver lining here, which is that trophy hunting is something we control very directly. … We can decide how many we’re going to shoot,” Creel says. On the other hand, “telling people who live in poverty that they can’t convert their land to agriculture, that’s suddenly a very difficult thing to accomplish.”
Tanzania allows trophy hunters to shoot only male lions that are at least 6 years old. Theoretically, this is better for the species as a whole than shooting lionesses, but Packer and Child agree that even killing just the adult males poses a serious threat. The country tries to cap the number of yearly kills at 500 in a 300,000-square-kilometer range. Packer thinks even a third of that is dangerous.
However, eliminating the hunt entirely could be even more dangerous. "If you make hunting too difficult, then people are going to switch back to cattle,” says Child. “And then you’ll have no wildlife.”
