This is because nomadic males often follow the migrating wildebeest up north during the dry season and return to the Serengeti in the wet season. Surprisingly, there is still no sure answer to the question of why lions have manes. In the past people thought that the mane acted as protection in fights against other males. But lions often fight by biting each other on the back. Another possibility is that the mane acts as a signal to other lions.
Lions are the only cats with manes, and only males have manes.
Signals that are only found in males, such as the peacock's tail as another example, are often shown to be attractive to females. Such signals may give the female information about whether the male would make a good mate. We are testing this idea with the Serengeti lions by using large, toy lions with varying manes. Lions do occasionally purr, but they are different from house cats in that purring is not common or important in their social life. Also, lions make a sound only as they exhale instead of continuously the way house cats do.