A Sierra Nevada red fox is shown in this handout photo taken with remote motion-sensitive camera provided by the National Park Service at Yosemite National Park, California, and provided on January 29. Biologists have spotted a Sierra Nevada red fox at Yosemite National Park for the first time - a sighting of one of the rarest mammals in North America, thought to number only 50 on the continent, officials said on Thursday. - Reuters/National Park Service/Handout