The expansion of the human species has advanced in tandem with the extinction of predators. Two-thirds of North America’s large mammals disappeared after humans’ arrival 10,000 years ago, likely because of competition for prey or outright extermination. During the 19th and 20th centuries, wolves, bears, and other modern predators were nearly hunted to extinction.
If large predators will survive the 21st century, human settlements must accommodate wildlife. Parks in the industrialized world, holding just a fraction of the world’s biodiversity, are not enough. A hopeful new study hints that predators and humans can live together, even in the developing world where deaths from wildlife are still relatively common.
The case study came out of Nepal’s Chitwan National Park, where tigers remain abundant despite large numbers of people entering their habitat either on foot or in vehicles. The authors say that the assumption that humans must be relocated out of sensitive wildlife habitats may be flawed. Empirical research on the question is scarce, but the findings from Chitwan suggest humans and tiger populations have increased without conflict because of behavioral changes and more local management.
"Tigers have adapted to human presence by becoming more active at night and less active during the day, when human activities peak," explained a statement released by the Proceedings of the National Academy of Sciences of the United States of America (PNAS), suggesting a new approach to predator conservation. By using camera traps and other monitoring techniques, the researchers found activity patterns of tigers (nocturnal) and humans (diurnal) would alternate, peaking at different times so the same terrain was used at very different times. "Our ﬁndings afﬁrm the notion that effective management policies, such as those policies that improve habitat conditions and lower exploitation, are more important to tiger conservation than human density per se," report the authors (PDF).
For the fewer than 4,000 tigers left in the wild (4% of the population just a century ago), the future may depend on finding ways for humans to share the landscape with wildlife. "Conservation plans informed by fine-scale spatial and temporal insights can help address a major global challenge-meeting human needs while sustaining wildlife in an increasingly crowded world," say the authors.