Fringe benefit. Nature parks can provide water and other resources for local residents, such as these herders in northern Kenya, who are allowed to graze pasture inside reserves.

George Wittemyer

Nature Parks: Loved to Death?

Nature reserves can be bad for animals and good for people. That's the counterintuitive bottom line of a new study showing that conservation dollars spent on infrastructure in and around these parks attract new residents, who in turn engage in illegal poaching and deforestation.

The extent of reserves set aside for wildlife conservation has risen by some 500% over the past 3 decades. In some countries, however, politicians have opposed the creation of new parks and nature reserves, arguing that they hurt rural people who lose access to traditional hunting grounds and other resources. But that logic didn't jibe with Justin Brashares, a conservation biologist at the University of California (UC), Berkeley. He noticed that the population of villages around national parks in Ghana was booming. At the same time, antelope and other wildlife in the parks were suffering from increased hunting.

Brashares teamed up with ecologist George Wittemyer of UC Berkeley to get the big picture. They analyzed United Nations population data for the areas surrounding 306 rural nature reserves in Africa and Latin America. In 245 of the reserves, population growth was higher in the 10-kilometer swath outside the reserve borders than it was in equivalent rural areas elsewhere, the team reports in the 4 July issue of Science. On average, population growth rates were almost double those in other rural areas. "Parks have become magnets for human settlement," Brashares says.

What's attractive about living near a park? The researchers note that international conservation grants often have a development component that aims to improve the lives of local residents, providing schools, roads, clinics, and other services. Indeed, population growth near the reserves was positively correlated with the amount of international conservation funding received. The local job market may play a role, too: People tend to move preferentially to parks that have relatively more employees. "The message comes through pretty loud and clear," says tropical ecologist S. Joseph Wright of the Smithsonian Tropical Research Institute in Balboa, Panama. "Parks are attracting and improving the life of people."

But the immigration doesn't improve the situation for wildlife in the parks. Brashares and Wittemyer cite other studies that show higher rates of logging, mining, hunting, and fires inside protected areas surrounded by humans. For example, when the duo looked at data on 55 forested reserves, they found that those with a 4% average annual population growth rate suffered more than 5% loss of forests, and those with a 2% average population growth rate lost less than 5% of forest. Wright has his own anecdote: Smithsonian researchers hired locals to work at a nature reserve in Panama and then discovered that the locals' relatives had also moved in and had begun poaching.

One solution, Brashares and Wittemyer propose, might be to invest development dollars in towns farther away from nature reserves to give an incentive for people to move away from parks. "The edge of parks have become battlegrounds for control of resources," Brashares says. "These battles are only going to intensify over the next decades, and we have to plan for that."