Black wildebeest
The black wildebeest or white-tailed gnu ("Connochaetes gnou") is one of the two closely related wildebeest species. It is a member of the genus "Connochaetes" and family Bovidae. It was first described in 1780 by Eberhard August Wilhelm von Zimmermann. The black wildebeest is typically in head-and-body length, and the typical weight is . Males stand about at the shoulder, while the height of the females is . The black wildebeest is characterised by its white, long, horse-like tail. It also has a dark brown to black coat and long, dark-coloured hair between its forelegs and under its belly.
List of animals of Yellowstone
Bison are the largest grazing mammals in Yellowstone National Park. They are obligate herbivores, a grazer of grasslands and sedges in the meadows, the foothills, and even the high-elevation, forested plateaus of Yellowstone. Bison males, called bulls, can weigh upwards of 1,800 pounds. Females (cows) average about 1,300 pounds. Both stand approximately six feet tall at the shoulder, and can move with surprising speed to defend their young or when approached too closely by people. Bison breed from mid-July to mid-August, and bear one calf in April and May. Some wolf predation of bison is documented in Canada and has recently been observed in Yellowstone. Bison live an average lifespan of 20–25 years in the wild.