Hunts, slaughter threaten bison in Yellowstone Park

Wildlife advocacy groups are suing to force the US government to look again at whether the hunting and slaughter of bison that wander outside of Yellowstone National Park threaten the survival of one of the last genetically pure populations of the national mammal.

Buffalo Field Campaign, Western Watersheds Project and Friends of Animals filed the lawsuit against the Interior Department and the US Fish and Wildlife Service Monday in US District Court in the District of Columbia. They are asking a judge to order federal wildlife officials to re-examine whether the Yellowstone bison should be listed as a threatened or endangered species.

Bison, which Congress designated as the national mammal earlier this year, were hunted to near extinction in the late 19th century. The estimated 4,900 Yellowstone bison are one of the last remaining populations in the U.S. that don't have cattle genes in their DNA.