A new study found that the Yosemite black bears have returned to their natural diet due to the Yosemite National Park's newly imposed food storage requirement for their visitors.
The Yosemite National Park houses hundreds of black bears and to initiate bear-to-visitor interaction, park officials began operating artificial feeding areas in 1923. However, it brought great changes to the black bears' eating diet. Instead of having their natural diet of berries, most of them started preferring human food, and the bears that were food-reliant became aggressive.
To prevent bears from stealing foods from the visitors, deaths, and injuries to human, the park spends $500,000 yearly on supplies and set new requirements for the food storage for the visitors -- brown metal food storage lockers for campers, and cylindrical plastic food storage for backcountry hikers. Everything must go into storage. They also encourage visitors to keep everything away from the black bear's sight even if it's their cars.
In a follow-up study, the researchers tracked the diet of about 200 black bears through analysis of their hair samples, as chemical signatures vary depending on food sources.
After analysis they found that only 13 percent of the food-reliant black bears appear to remain reliant on human food, a rate similar to the early days of the park. It also suggests that the park official's massive effort was effective.
"Reducing the amount of food on the ground and making sure visitors are compliant with food storage has led to this management success. It appears that management that is related to preventing bears from becoming too conditioned to food in the first place is one of the best things to put money into," said lead study author Jack Hopkins, a wildlife ecologist at the University of California, Santa Cruz to Live Science.
This study was published in the March issue of Frontiers in Ecology and the Environment.
