By late August, the bull elk's antlers stop growing. The blood vessels inside the velvet dry up, causing the velvet to fall off, and the bulls rub the velvet off on trees and brush. In the fall, elk also begin to shed their thin summer fur and grow warm winter coats. This is when the calves lose their spots.
Bulls bugle to let the cows know they are there and to scare other bulls away.
Each bull tries to convince the cows that he's the healthiest and mightiest elk around because the cows want to mate with the biggest and smartest bull so that their calves will be big and smart too. When two large bulls cross paths, they wage violent battles for control of the harem. During the rut, the elk are so busy that they can't eat much, and the bulls use up lots of energy chasing cows and fighting. So in the weeks after the rut, the elk must eat constantly to build up fat in order to survive the oncoming winter. Click on a thumbnail to see the larger image.