Tourists—unless they are too unruly—may be helping wild brown bears increase their numbers. Noisy humans can drive big male bears away from their normal feeding zones, which allows mothers and their cubs to eat in peace, say researchers from the University of Central Lancashire and Utah State University. Because cubs are sometimes killed by the males, more young bears survive. Brown bears, also called grizzly bears or Kodiak bears, can be found in the wilderness and mountains of North America, Asia and Europe. But in the United States, their numbers are dwindling: Fewer than 1,000 brown bears are left, and most of those are found in protected national parks, including Yellowstone.