Lions are the only big cats to live in family units called prides. Other big cats live solitary lives, except when breeding or raising cubs. A lion pride may include up to three males, a dozen females, and their young. Lionesses are the primary hunters, while dominant males are responsible for protecting the pride's territory. Lion prey includes antelopes, zebras, wildebeest, buffalo, and other grassland animals. These animals are often larger and faster than an individual lion. By hunting together, lions are able to exhaust and kill their prey. Tsaro lions are called swamp cats. They hunt water buffalo by stampeding them into the water where they can attack and kill the young or weak members of the herd. After the initial stampede, the lions herd the buffalo through the water and relentlessly pursue them for hours at a time. Each attack weakens the herd, resulting in a feast for the Tsaro pride.