Published: Jul 07, 2011 5:56 PM EDT
Updated: Jul 07, 2011 4:57 PM EDT

YELLOWSTONE NATIONAL PARK, Wyo. (AP) - A Yellowstone National Park official says authorities won't try to capture a female grizzly bear that killed a backcountry hiker because it was trying to defend her cubs when she was surprised by the man.

Park spokesman Al Nash said Thursday the mauling of a 57-year-old man was a purely defensive act by the bear. He said Yellowstone typically does not try to capture or remove a bear in what he calls a wildlife incident.

Wednesday's attack occurred about 1-1/2 miles up a popular backcountry trail and was the first fatal grizzly attack inside the park in 25 years - but the third in the Yellowstone region in just over a year.

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