What could make a baby bison white?

By CHRISTINA LARSON
AP Science Writer

WASHINGTON (AP) — Photos of a white bison calf in Yellowstone National Park have generated excitement as well as questions: How does that happen? A park visitor said she took the photos earlier this month, showing a fuzzy white youngster being nuzzled by its dark brown mother. Park officials said this week that they hadn’t yet spotted a white calf in the sprawling park that is home to about 5,000 bison, also called American buffalo. In the wild, there are two genetic variations that may result in unusually light-colored animals. The mutations result in either a partial loss or a complete loss of pigmentation.