In the Serengeti, which has a 50-year-record of arrests and patrols, the scientists divided the number of poachers arrested by the number of patrols a day to estimate the amount of poaching. They assumed that arrests per patrol were representative of poaching intensity and not, for instance, that officer training or informant networks improved.
"We show that a precipitous decline in enforcement in 1977 resulted in a large increase in poaching and decline of many species," Hilborn and his co-authors write. "Conversely, expanded budgets and antipoaching patrols since the mid-1980s have significantly reduced poaching and allowed populations of buffalo, elephants and rhinoceros to rebuild."
Outside of established reserves, using tourism or hunting expeditions to generate economic benefits for local communities is the cornerstone to enlisting their help in protecting wildlife, Hilborn says. But the community conservation programs initiated in Tanzania since 2000 occurred after stepped-up patrols in the Serengeti proved effective.
"Antipoaching is effective in protected areas," he says.
The work marks the first time anyone has been able to reconstruct a history of poaching going back as far as 50 years, says Tom Hobbs, professor of ecology at Colorado State University and who is not affiliated with the work being published in Science.
"The Hilborn team has shown that protection of wildlife by active enforcement of laws and regulations remains an essential tool for conserving biological diversity," Hobbs says. "This sounds so simple, but it has been controversial."
Source:University of Washington