Vivvo CMS 4.1 PRI: Public Radio International http://www.pri.org/ ©2010 Spoonlabs d.o.o. PRI: Public Radio International http://www.pri.org/files.php?file=rss_682409203.gif http://www.pri.org/ What's behind the grizzly bear attacks in Yellowstone? http://www.pri.org/stories/science/environment/what-s-behind-the-grizzly-bear-attacks-in-yellowstone-10336.html Environment Wed, 20 Jun 2012 09:00:00 -0500 Grizzly bears killed two people last year in Yellowstone National Park. After 24 years of no deadly encounters, many people were left wondering what caused the fatal attacks. Some said global warming had depleted the bears' normal food sources. Others say the answer is much simpler. PRI: Public Radio International