This, coupled with longer, coarser hair on the neck and shoulders, gives them the appearance of having manes, as do lions. Color gradually lightens as the animal ages and periodically molts. Most adult females are a yellowish, cream color on the back, although some remain darker. Males and females have a marked size difference. Females grow rapidly during the first four years but slow by the fifth year, with little growth after age 6.
Males continue to grow until the eleventh year.
Although there are variations, most females reach maximum size by the seventh year, and males reach adult size by the twelfth year. Although only 20 percent longer, the average adult male weighs over twice as much as the average adult female. They mate with females which give birth, then come into estrus in their territory. Females give birth to a single pup anytime from mid-May through July. They breed shortly after giving birth, but the fertilized egg does not implant in the uterus and begin growing until October.