A female elephant will have a single baby (called a "calf") every four or five years. Calves are born tall and weigh around . An elephant's gestation lasts about 22 months. Another female elephant often stays with the new mother until its baby is born. The newborn elephant can often stand within a half hour after it is born. Mother elephants touch their babies gently with their trunks. It takes a baby a year or more to control its trunk and learn its many uses.