Wildebeest
Both species of wildebeest are even-toed, horned, greyish-brown ungulates resembling cattle. Males are larger than females and both have heavy forequarters compared to their hindquarters. They have broad muzzles, Roman noses, and shaggy manes and tails. The most striking morphological differences between the black and blue wildebeest are the orientation and curvature of their horns and the color of their coats. The blue wildebeest is the bigger of the two species. In males, blue wildebeest stand 150 cm tall at the shoulder and weigh around 250 kg, while the black wildebeest stands 111 to 120 cm tall and weighs about 180 kg. In females, blue wildebeest have a shoulder height of 135 cm and weigh 180 kg while black wildebeest females stand 108 cm at the shoulder and weigh 155 kg. The horns of blue wildebeest protrude to the side, then curve downwards before curving up back towards the skull, while the horns of the black wildebeest curve forward then downward before curving upwards at the tips. Blue wildebeest tend to be a dark grey color with stripes, but may have a bluish sheen. The black wildebeest has brown-coloured hair, with a mane that ranges in color from cream to black, and a cream-coloured tail. The blue wildebeest lives in a wide variety of habitats, including woodlands and grasslands, while the black wildebeest tends to reside exclusively in open grassland areas. In some areas, the blue wildebeest migrates over long distances in the winter, whereas the black wildebeest does not. The milk of the female black wildebeest contains a higher protein, lower fat, and lower lactose content than the milk of the blue wildebeest. Wildebeest can live more than 40 years, though their average lifespan is around 20 years.
Black-tailed jackrabbit
The black-tailed jackrabbit does not migrate or hibernate during winter and uses the same habitat of 0.4 to 1.2 mi (1–3 km) year-round. Its diet is composed of various shrubs, small trees, grasses, and forbs. Shrubs generally comprise the bulk of fall and winter diets, while grasses and forbs are used in spring and early summer, but the pattern and plant species vary with climate. The black-tailed jackrabbit is an important prey species for raptors and carnivorous mammals, such as eagles, hawks, owls, coyotes, foxes, and wild cats. The rabbits host many ectoparasites including fleas, ticks, lice, and mites; for this reason, hunters often avoid collecting them.
Like other jackrabbits, the black-tailed jackrabbit has distinctive long ears, and the long powerful rear legs characteristic of hares. Reaching a length about , and a weight from , the black-tailed jackrabbit is the third-largest North American hare, after the antelope jackrabbit and the white-tailed jackrabbit. The black-tailed jackrabbit's dorsal fur is agouti (dark buff peppered with black), and its undersides and the insides of its legs are creamy white. The ears are black-tipped on the outer surfaces, and unpigmented inside. The ventral surface of the tail is grey to white, and the black dorsal surface of the tail continues up the spine for a few inches to form a short, black stripe. The females are larger than males, with no other significant differences.