Driven by a surge of hormones, the bucks, especially the largest and oldest males with their impressive rack of antlers, are now continuously on the move as they attempt to locate females nearing their estrous, or heat period. Rather than spend time resting or sleeping, bucks are on the go day and night in the days prior to, and immediately after, Veteran’s Day, as these individuals experience an innate urge to focus all their time and energy into spreading their genetic composition into the deer herd of that area.
A doe is receptive for only a 24 to 30-hour period, so a buck must service her during this brief time frame if her eggs are to become fertilized. In the days prior to coming into heat, a doe advertizes her condition by emitting various chemicals to her surroundings. Upon detecting any of these odors, a buck immediately follows her scent trail in an effort to locate her before any of his rivals. Once he encounters the doe, he attempts to breed with her. However, if the doe is not quite receptive yet, his advances go unanswered. The buck then remains with her until the time is right, or until another larger and more powerful buck arrives on the scene. In this instance, there is a battle between the two males to see which of the suitors will win the privilege to mate with her.
The dominant buck of an area must be successful in driving away younger rivals, as the presence of these individuals reduces his chances of guaranteeing that only his sperm will enter her reproductive tract. After breeding with a doe, a buck is strongly inclined to remain with her until her estrous period passes. The odor of other does nearing their heat period coming from a short distance away can prevent a buck from remaining with a recently bred doe. Should a buck stray too far from her immediately after mating, a subordinate buck could sneak back and breed with the still receptive doe and get his genetic material into that arena where fertilization eventually takes place. For the day, to day and a half period when a doe is receptive, she may breed with more than one buck if that opportunity arises.
Researchers believe that the time in autumn when a doe comes into heat is based primarily on a response to a specific amount of daylight, also known as photoperiodism. This is why rutting occurs in one general region every year at nearly the same time. Weather is also believed to influence the timing of this event to some degree, as well as the lunar cycle and the nutritional status of each individual.
While a few does experience their estrous period at the very end of October, the vast majority of white-tails come into heat around the second week of November. The great number of does in need of a buck’s services during this short time frame places tremendous physical stress on the bucks. The need to reproduce forces them to continuously track down soon to be receptive does and fight off rivals. Larger bucks have been known to lose as much as 10% of their body weight during this week to 10 day long event, as these animals often fail to eat, or are unable to eat enough to provide them with the energy lost during this phase of their life.
By the end of next week, most of the does in the Adirondacks will be successfully bred. The females that failed to breed on time experience a second heat period in another 28 days. This creates an event in hunting known as the second rut, which occurs in early to mid December, shortly after the close of big game season in this northern zone.
It has been said by some sportsmen that older and larger bucks are more active during this period of time, as the younger males have not yet recovered from the exhaustion experienced during the primary rut.
When operating a car during early to mid November, it is especially important to be alert for deer crossing highways. For much of the year, deer tend to be most active around the hours of dawn and dusk, however, with the onset of rutting season, bucks are actively moving at all hours of the day and night, as are some females looking for a buck to fertilize her eggs. There are times, such as when it is raining or the wind is blowing, when deer bed down and do not move which minimizes the chance of a deer collision. However, don’t count on this rule as rutting season changes everything.
Photo courtesy Duke University.