Female chamois with two kids in autumn, in their natural environment. The younger without horns was born in May or early June, the other is called a yearling and was born the previous year. The kids do not reach sexual maturity until they are 3 to 4 years old, although some females may mate at as early 2 years old. At sexual maturity, young males are forced out of their mothers herds but dominant males (who sometimes kill them) and then wander somewhat nomadically until they can establish themselves as mature breeding specimens at 8 to 9 years of age.