Jack Hopkins, University of California - Santa Cruz (image) University of California - Santa Cruz Share Print E-Mail Caption Researcher Jack Hopkins used barbed-wire snares to collect hair samples from bears in Yosemite National Park. Analysis of isotope ratios in hair samples showed how much of the bears' diets came from human food. Credit Photo courtesy of Jack Hopkins Usage Restrictions For use only with news coverage of this research Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.