Rut (mammalian Reproduction) - White-tailed Deer

White-tailed Deer

The rut for white-tailed deer (Odocoileus virginianus) usually lasts from 1–3 months in the Northern Hemisphere and may occur most of the year in tropical zones. The rut is the time when white-tailed deer, especially bucks, are more active and less cautious than usual. This makes them easier to hunt, as well as more susceptible to being hit by motor vehicles.

Some people believe that the white-tailed deer rut is also controlled by the lunar phase and that the rut peaks seven days after the second full moon (the rutting moon) after the autumnal equinox on 21 September. However, study of white-tailed doe conception dates conducted in Minnesota between 1980 and 1987 showed no correlation between peak breeding dates of white-tailed deer and any lunar phase.

A white-tail doe may be in estrus for up to 72 hours, and may come into estrus up to seven times if she does not mate. Cow elk may come into estrus up to four or more times if they do not mate.

The breeding season for white-tailed deer is also known as a term call the “rut.” The rut is a time period, usually during late fall, when deer, elk, and other species from the deer family breed. The male, or in this case the buck, will chase after many does for weeks, with barely eating. The buck has one thing on his mind at this time of the year, and that is to find as many does as he can. The rut can take its toll on the bucks; they are definitely worn out by the end of the breeding season.

The rut can start as early as the end of September, and can last all the way through the winter months. Bucks begin to start this process usually when the velvet is falling off their antlers. This process can last all the way until they start to shed their antlers. The peak of the rut however, is right in the middle. Studies have shown that the “average peak day for the rut in the U.S. is November 13.” Around this period of time, the bucks and does are very active, with the rut in full swing. For a hunter sitting in a tree stand at this time of the year, it is not uncommon to see many deer pass through your specific area, due to other deer chasing others. The rut is definitely a busy time for the white-tailed deer.

There are many behaviors a buck will do during the rut. During pre-rut, bucks will spar with each other. Sparring is just somewhat messing around and pushing each other. Bucks of different sizes will do this to each other. Don’t get this mixed up with fighting however. Fighting is an entirely different thing. After pre-rut is finished, a buck will rub his antlers on a tree, thus making a “rub”. This is one way a buck will mark his territory. A buck will also make scrapes on the ground with his hooves, this also is a way in which a buck will mark his territory and proclaim his dominance for other bucks to see. These activities are nocturnal; usually done during the night hours.

The biggest behavior of all during the heat of the rut is fighting. This is where bucks show their true dominance to the others. Usually the bigger the buck, the more dominant he is. Fighting is usually where bucks battle against similar sized deer. Usually, you won’t find a small buck fighting with a mature large one. Most often than not, the smaller bucks are afraid of the more mature bucks, and somewhat leave the dominant deer’s territory. The fights can go on and on, with the winner getting the group of does. Some fights go on until death, and if not death, it is not unusual to see one of them get injured.

With all the chasing and fighting during the breeding season, a buck can lose an immense amount of weight. Research shows that a buck can lose up to “20%” of his body weight in these months. On average, a buck before breeding season can weigh up to “180pounds”. After he has gone through the stages of rut, he can weigh about “135 pounds”. This is about 50 pounds of lost weight, which is a lot, especially for only a few months of time. In the post-rut, a buck will need to replenish his body and catch up on the weight and energy he has lost.

Sources have said that after the rut, a buck will go to a bedding spot and will remain “motionless” for a large amount of time, even to the extent of about two days. The buck is thoroughly exhausted. After he has rested, he will get up and start to feed. He will eat and eat, trying to catch up on all the needed nutrients his body requires. Croplands have a lot of high nutrient grain in them, and a buck can be found here often times, eating and getting nutrients. When the climate is extremely cold, a buck will sometimes resort to swamps and bogs, because of the warmer temperatures these areas hold. As you have seen above, the rut is a strenuous process on deer and can really wear them out. There are many steps and stages they all go through, and the bucks definitely run themselves ragged, losing a lot of their weight and energy. They will shed their antlers and grow a new set in the spring; then come fall, the process will start again.