Wildlife managers estimate that more than 570 Yellowstone National Park bison have been killed so far this winter. The Bozeman Daily Chronicle reports that the numbers show that bison managers are making progress on their goal to eliminate 1,300 bison from the Yellowstone herd. A 2000 management plan calls for a population of 3,000 bison in the region, but about 5,500 live there now. A Yellowstone report says 179 bison have been transferred to Native American tribes for slaughter and 359 have been killed by hunters as of last Friday. A Montana Fish, Wildlife and Parks report on the bison hunt compiled last week shows a lower number of confirmed bison kills but says officials believe more the total number of bison hunted and killed is already above 400.