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Fauna
Yellowstone is widely considered to be the finest megafauna wildlife habitat in the lower forty eight states. There are almost sixty species of mammals in the park, including the gray wolf, the threatened lynx, and grizzly bears. Other large mammals include the bison (buffalo), black bear, elk, moose, mule deer, white-tailed deer, mountain goat, pronghorn, bighorn sheep and mountain lion.Yellowstone Park Bison Herd is the largest public herd of American Bison in the United States. The relatively large bison populations are a concern for ranchers, who fear that the species can transmit bovine diseases to their domesticated cousins. In fact, about half of Yellowstone's bison have been exposed to brucellosis, a bacterial disease that came to North America with European cattle that may cause cattle to miscarry. The disease has little effect on park bison, and no reported case of transmission from wild bison to domestic livestock has been filed. However, the Animal and Plant Health Inspection Service has stated that Bison are the В«likely sourceВ» of the spread of the disease in cattle in Wyoming and North Dakota. Elk also carry the disease and are believed to have transmitted the infection to horses and cattle. Bison once numbered between thirty and sixty million individuals throughout North America, and Yellowstone remains one of their last strongholds. Their populations had increased from less than fifty in the park in 1902 to four thousand by 2003. The Yellowstone Park Bison Herd reached a peak in 2005 with four thousand nine hundred animals. Despite a summer estimated population of four thousand seven hundred in 2007, the number dropped to three thousand in 2008 after a harsh winter and controversial brucellosis management sending hundreds to slaughter. The Yellowstone Park Bison Herd is believed to be one of only four free roaming and genetically pure herds on public lands in North America. The other three herds are the Henry Mountains Bison Herd of Utah, at Wind Cave National Park in South Dakota and on Elk Island in Alberta, Canada.combat the perceived threat, national park personnel regularly harass bison herds back into the park when they venture outside of the area's borders. During the winter of 1996-1997, the bison herd was so large that one thousand and seventy nine bison that had exited the park were shot or sent to slaughter. Animal rights activists argue that this is a cruel practice and that the possibility for disease transmission is not as great as some ranchers maintain. Ecologists point out that the bison are merely traveling to seasonal grazing areas that lie within the Greater Yellowstone Ecosystem that have been converted to cattle grazing, some of which are within National Forests and are leased to private ranchers. APHIS has stated that with vaccinations and other means, brucellosis can be eliminated from the bison and elk herds throughout Yellow...
