The stags leave the females when the rut is over, forming bachelor herds for the rest of the year. The calves are born after a gestation period of eight and a half months. They are able to stand unsteadily at 20 minutes old, and are able to take milk 10 minutes later. A calf will stay with its mother until she gives birth again. At this time, she drives it away so that it will not compete with the new calf.
Deer hunting is a popular, though controversial, sport.
But the number of deer must be controlled each year, to prevent the herds from exhausting their food supply. Hunting, therefore, is seen as a necessary population control. Some species of deer are bred like cattle, but red deer are not suitable to be raised on ranches because they become dangerous during the rut. The red deer are common and increasing, culling in many places, and protected both as game and as ornamental animals. The stag uses his antlers as a weapon when fighting other males for access to females during the mating season each fall.