During the rut, many physical and social changes take place in deer. The shortening of daylight triggers certain hormones to rise in the deer. During the rut testosterone levels in the bucks increase, causing the velvet to be shed from the antlers, and the neck becomes larger. During this time bucks separate from the groups they lived with during the summer.
Bucks begin to spar with their antlers as a test of strength and a way to establish dominance.
Bucks also begin to seek out does in heat and also begin to signposting. Signposting is done by scrapping a spot on the ground and depositing scent on over hanging branches. The buck also deposits scent on the ground with the glands on the legs. Does in heat respond to signposting by urinating in the scrap. The actual rut last for about a month.