Setting Boundaries

African lions are better off in fenced reserves than roaming free, researchers argue in Ecology Letters.

People seeking to protect large carnivores such as lions face a choice: Should the animals be kept separate from humans or allowed to range unfettered over the land? In parts of Africa, fences have kept many lions from harming people and livestock, “yet this strategy runs counter to a long-standing conservation ethic of keeping protected areas unfenced,” the authors write.

The team wanted to find out whether lions fared better with or without fences. So the researchers examined data from 42 sites in Africa, some of which had been surveyed for decades, and estimated how much the lion populations had grown.

The populations grew faster in fenced reserves over the last decade than they did in unfenced areas, the authors report. And lion populations behind fences will likely “remain at or above their full potential” over the next century, the team predicts. In contrast, many unfenced sites will struggle to support even 10 percent of their potential population in the next few decades.

Nearby people are also less likely to affect fenced than unfenced lions, the study says. While fences are expensive to build, they cut management costs once they’re in place. Roberta Kwok | 7 March 2013

Source: Packer, C. et al. 2013. Conserving large carnivores: dollars and fence. Ecology Letters doi: 10.1111/ele.12091.

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