Yosemite National Park has helped cut the amount of human food eaten by black bears by 63 percent after requiring that visitors lock up their food, baby wipes and even toothpaste, according to a new study. Researchers tracked the diets of 200 black bears by analyzing the chemical signatures in hair samples, Live Science reported. "What we found was that the diets of bears changed dramatically after 1999, when the park got funding to implement a proactive management strategy to keep human food off the landscape," said Jack Hopkins, lead study author and a wildlife ecologist at the University of California, Santa Cruz. "This suggests that the bear's diets are likely going back to their natural diet." Yosemite spends about $500,000 annually on supplies, outreach and other efforts to prevent bears from eating human food.