As I sat in my stand on the field's edge, I glanced to the east just as the moon was clearing the treetops. Like thousands before me, I contemplated what, if any influence it had on deer movement. Would tonight be a good night to hunt? The moon was nearly full, and conventional wisdom said most activity took place after dark. Furthermore, the moon was just rising. It wouldn't be overhead for several hours, and the latest moon theory said that peak activity occurs when the moon is directly overhead. Besides, it was only the first day of November. The rut was still at least a week away.

Bucks begin rubbing as soon as their velvet sheds. Rubbing intensifies leading up to the seeking phase, making this a good time to take rub lines into consideration when choosing a stand site.

Theories about the moon's relationship to deer abound, and probably have for nearly as long as man has walked the earth. To quote writer Jeff Murray in his book Moon Struck, some hunters swear by the moon, others swear at it. Even today, researchers and non-professionals disagree on how the moon influences deer behavior. However, a pair of dedicated whitetail enthusiasts have joined forces to come up with some enlightening theories and a substantial body of evidence to support their contentions. Applying what they've learned could help you maximize your time afield this fall.

The name Charles J. Alsheimer is a familiar one to most serious whitetail hunters. If you've never heard it, just look closely at the photo credits in most major deer hunting magazines. Alsheimer has been hunting, observing and photographing whitetails for almost four decades. A name perhaps less familiar is Wayne Laroche. Laroche is an avid whitetail enthusiast too, and a professional wildlife biologist who has been hunting and studying whitetails for just as long.

Laying The Foundation
In 1994, the pair teamed up. Laroche's interest in moon-phase theory began in the early 1990s. Traveling from his native Vermont to Maine, he noticed striking differences in rut sign and behavior from year to year, and he wanted to know why. Knowing from his research that moonlight affects fish, he wondered if it could have a similar effect on whitetails. Alsheimer's interest began in the late 1980s, spawned from many hours afield photographing, observing and hunting deer. What he was seeing just didn't jibe with the accepted theories at that time.

Laroche began compiling evidence. We know that a whitetail's pineal gland responds to changes in the amount of daylight by releasing hormones, which ultimately triggers the reproductive cycle. The accepted doctrine was that daylight meant sunlight, and since this varies little from year to year, it seems plausible that the rut should be relatively consistent on an annual basis. However, the moon also produces light. Furthermore, the period of greatest moonlight varies from year to year, depending on when the full moon falls in the calendar year. Laroche noted that the brightest full moons occur in November and December.

He also uncovered another interesting fact. Most does are bred under a dark-moon period. Jumping ahead to an average 199-day gestation period, he calculated that most fawns are born within a day of the third-quarter moon. The adaptive advantage of this is obvious. Fawns born during a dark moon phase have a better chance of avoiding or escaping predators.

Based on this and other evidence, Laroche eventually formed a hypothesis. He believes decreasing amounts of daylight prime a doe's reproductive cycle. Then more subtle changes occur with the amount of available light, cued by moonlight that triggers hormonal production by the pineal gland. Alsheimer explains in his book Hunting Whitetails by the Moon, "A northern doe's estrogen level peaks around November 1 as does a buck's sperm count. With both sexes poised to breed, it stands to reason a mechanism must be in place if the doe is to enter estrus and be bred under the darker phases of the moon, which is the third quarter to first quarter. That mechanism in the north is the second full moon after the autumnal equinox, which I call the rutting moon."

Observing The Rut
Numerous research projects and myriad hours of anecdotal evidence have yet to produce any conclusive findings on how general deer activity corresponds to moon phase. However, many well-known whitetail authorities maintain there is a connection. Texan, John Wootters, a mainstay of Petersen's Hunting, is one such authority. In his book Hunting Trophy Deer, Wootters had this to say: "I've seen scientific correlations that tended to show the phase of the moon has nothing to do with whitetail activity, if all other things are the same. Which convinces me that either the deer haven't seen the same charts or all other things are never the same. I will go to my grave unshakably convinced that exactly the opposite is true, and that moon phase is critical to a hunter's plans."

Moderate sparring during the early part of the fall season will give way to all-out battles as the rut peaks. If you choose to rattle, vary the intensity to correspond with the animals' current levels of aggressiveness.

While the moon phase may have little affect on the day-to-day activity levels, Alsheimer and Laroche's work has generated some enlightening evidence on how moon phase affects the rut, in terms of both timing and intensity. The widely accepted belief among most biologists is that peak breeding north of the Mason-Dixon line occurs around November 15 every year, and is set by photoperiod. Most of the evidence for this comes from measuring fetuses in the spring, and backdating. However, even biologists will admit this method has a 20-day margin of error. That means the actual peak breeding period could occur anytime within ten days before or after November 15. It is Alsheimer's contention that this date varies annually according to how the moon phase corresponds to the calendar. He also believes that when the Rutting Moon falls during the first eight days of November, the rut's intensity is greater.

When you consider that the rut is triggered by photoperiods, this only makes sense. The moon too is a source of light, which increases in intensity approaching the full moon. If you don't believe the whitetail's estrous cycle is correlated with the moon consider this: the lunar cycle is 29.5 days, and the whitetail estrous cycle is 28-29 days.

Knowing they faced an army of critics, Laroche and Alsheimer began intensively studying a group of deer under controlled conditions. Most notable in their findings thus far is that nearly 80 percent of mature does are breeding during a 14-day window predicted by Laroche's hypothesis. Assuming Laroche's theory is correct, it has direct application for the hunter.

Application
Pre-rut is generally considered a slow period. You'll recall this is the first full moon after the fall equinox. It begins a couple days before the pre-rut moon and ends seven days before the rutting moon. It is still early fall. Though deer are growing their warm winter coats, temperatures are warm and deer, especially bucks, are less active. They tend to stick to their core areas and move mostly during the cooler hours of twilight and night. The cooling nights, however, signal deer that fall and winter are on the way. Feeding intensity picks up and deer begin switching from high-protein summer foods to fall foods that are rich in carbohydrates.

This is the time to hunt food sources, especially those close to bedding cover. You don't want to hunt too close to bedding however, as you may move deer out of the area completely. You also want to stay away from rut hotspots. According to another whitetail authority, Mark Drury, this is one of the biggest mistakes hunters make. "Every year I see it. Guys do their scouting, and then come October first, they're in there hunting their best rut spots. They burn their stands out because of over-anxiousness. By the time the rut arrives, every one is used up. Early in the season you can do some afternoon hunting in or near food sources, but save your good stands for the rut."