LUNAR RUT PREDICTIONS-2003
What a year it has been. Last year, when my yearly article on Lunar Rut Predictions came out in the October 2002 issue of Deer and Deer Hunting the title line read, 2002 Lunar Forecast: The Worst Rut Ever? Shortly after, my phone started to ring. Some thought I was on to something, while others said I was crazy. Many said, "It took a lot of guts for you guys to make that prediction." Well, not really. Though Wayne Laroche and I certainly took an unorthodox approach, when we predicted a "trickle rut" and a later than normal November breeding in the North for 2002, it wasn't based on a whim. We based our predictions on hard scientific data, accumulated over seven years.
To make a long story short, what we predicted for 2002 was exactly what happened in the North. Not only did our computers and reporting stations confirm this but we heard from over a hundred hard-core hunters and outfitters across America who confirmed at season's end what we had predicted. The bottom line to 2002 was that hunters were scratching their heads last November, trying to figure what was going on. In a nutshell the 2002 rut was far less intense than other years and as "on again, off again," as anyone could ever remember. The good news is that you will not see a repeat of 2002 until 2005, so you have a couple of good years to look forward to before another mess like last fall returns. Before I predict what will occur this fall let me bring everyone up to speed.
In case you're a new subscriber to Deer and Deer Hunting, or can't remember the details of how to predict the moon's influence on whitetail rutting behavior I'll offer the following.
For the last eight years, Vermont wildlife biologist Wayne Laroche (who is also Vermont's commissioner of fish and wildlife) and I have been researching the influence the full moon has on the timing of the whitetail rut in the North. In its ninth year, the project is expected to run for fifteen years. Why so long? There are a number of reasons, but the primary factor is the fluctuation in the timing of what we refer to as the Rutting Moon (the second full moon after the autumnal equinox).
Those who have followed our work know that the timing of the Rutting Moon comes within a day or two of repeating itself every eleven years and reasonably close to repeating itself every three to four years. Consequently, it's important to collect good data over an extended period of time in order to evaluate the moon's impact on white-tailed deer rutting activity.
Genesis of the Work
Though we've been collecting data for the last eight years, our interest in this project was born well over a decade ago.
Laroche is a respected fish and wildlife biologist and an avid whitetail hunter who spends the entire deer season in northern Maine chasing big woods bucks. He became interested in the moon's influence on whitetails after researching the impact the moon has on Grouper fish in the Caribbean and the Gulf of Mexico. As he hunted the Maine woods every year, he noticed distinct fluctuations in whitetail activity patterns. After studying the yearly changes he began to wonder if the moon was affecting the way whitetails behaved during November, just as it had influenced the fish he had studied years before.
My interest in lunar-related behavior began in the late 1980s while hunting and photographing. Up until then I had bought into the research data that had originated in the 1950s and 60s that said the peak breeding period for whitetails in my region of the North (42nd latitude) would be November 15-20 each year.
Over a ten-year period from 1985 to 1995 I had the opportunity to photograph whitetails on a very large property in the Adirondack Mountains of New York. During this time I shot hundreds of rolls of film and kept detailed notes on deer behavior. Despite the deer population and adult-doe-to-antlered-buck ratio remaining the same, the peak breeding period was seldom the same from year to year. Some years the breeding took place in early November, some years late November, and other years mid-November.
In 1995 I built a 35-acre white-tailed deer research facility on our farm and have seen a repeat of what I saw in the Adirondacks. After nearly of twenty years of data collection it's obvious to me that something more than photoperiod, or shortening day length, plays an integral role in the timing of the whitetail rut in the North.
In the early 90s Laroche and I met when I did a magazine article on other deer research he was conducting. During one of our initial conversations Laroche commented that he believed the moon was partly responsible for the fluctuations in deer activity that both he and I were seeing during November. From this a fascinating research project evolved.
To provide further background and help you better understand the project, I'll offer the hypothesis for our research.
At some point in autumn, the amount of daylight decreases enough to reset the whitetail's reproductive clock, thus placing the breeding season in November, December and January in the Northern Hemisphere. Once the doe's reproductive cycle is reset by a specific amount of daylight, her estrous cycle is ready to be cued by moonlight, which provides a bright light stimulus to the pineal gland several nights in a row each lunar month. Then, the rapid decrease in lunar brightness during the moon's third quarter (the quarter after the full moon), triggers hormonal production by the pineal gland. Physiological changes prompted by the pineal gland culminate in ovulation and estrus.
A Northern doe's estrogen level peaks around November 1st 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 are the third through first quarters. That mechanism in the North (north of about the 35th latitude) is the second full moon after the autumnal equinox, which we call the Rutting Moon.
What We Know
With each passing year we've added more and more data collection devices to the research project. In the beginning we only had six adult does to monitor. We now have upwards of 100 does to draw data from.
We also monitor air temperature, weather patterns and moonlight intensity throughout the fall. In addition we have twelve Model 500 Trail Timers to record deer activity throughout each day. Four of the timers are in my farm's research facility and, at any one time, up to eight are positioned in other areas of the farm to monitor the wild, free-ranging whitetail population. The data, which is collected from October through December, is downloaded to our computers for analysis.
Unlike eight years ago, when no one else was helping us, we now have several serious deer hunters, whitetail breeders and outfitters across North America (who are in the woods every day during the fall) keeping detailed journals to chronicle deer behavior in their regions of the country. This added information has allowed us to better understand what is happening in other parts of North America during October, November and December. An example of this is what we call our Maine Lab which I described in detail in last year's lunar update.
After eight years and 15,000+ computer data points (as well as hundreds of visual observations) we've observed that the second full moon after the autumnal equinox stimulates both buck and doe rutting activity. Based on observed behavior we've broken the rut into three phases; seeking, chasing and breeding. Without exception it's been the Rutting Moon that has triggered the seeking phase, which is the beginning of the rut.
Interestingly we have seen that some ruts are more intense than other and believe there are several reasons why this is so. Certainly, temperature, adult-doe-to-antlered-buck ratios, presence of mature bucks, and human pressure play a part in the rut's timing and intensity but the biggest factor is when the Rutting Moon occurs.
We've observed that when the Rutting Moon occurs between about November 1 and 12 the rut is most intense, especially in a well-tuned deer herd, where the buck to doe ratio is good, mature bucks are common and the temperatures cool. When the Rutting Moon falls in this time frame we believe the stage is set for what we call "a classic rut."
Nothing will keep a rut from taking place. However, the project has revealed several factors that can greatly affect daytime deer activity.
Air temperature: As reported in previous lunar updates, our Trail Timer/computer-generated data has shown that when the daytime temperature here in western New York rises above 45 degrees during the rut deer activity begins to fall off. With their heavy fur coat and inability to ventilate as humans do, deer simply cannot function in warm weather.
Sex ratios: Adult-doe-to-antlered-buck ratios greater than three to one also decrease deer activity. This is primarily due to the fact that does are less active than bucks in November. When there are far more does than bucks in a population, every available buck is with a doe when the breeding phase of the rut arrives. On the other hand, in areas where the adult-doe-to-antlered-buck ratio is one-to-one or two-to-one, buck activity is greater because there are far less does to go around, resulting in competition between bucks for breedable does. As one might expect, we also see greater buck activity in populations that have more mature bucks in the herd.
Human pressure: The impact of human pressure is perhaps the mother of all rut suppressors, especially when daytime air temperatures are unseasonably warm, which in the research project's location is 45 degrees or warmer. Our Trail Timer data shows that approximately 55 percent of deer movement occurs during daylight hours in areas where there is little or no human presence. In areas where there is moderate to heavy human activity, only about 30 percent of deer movement is during daylight.
What we've learned in the last eight years has been incredible. It's now obvious that day length plays a major role in setting the stage for the whitetail rut, but there is far more to the equation than just shortening day length. As the data shows, the moon does indeed play a part in timing the whitetail's rutting activity in the North.
This fall the second full moon after autumnal equinox will occur on November 9th. We have a lot of excellent data for a year like 2003 and firmly believe that this fall deer hunters will see a classic whitetail rut. For those of you who keep accurate records it should be a near repeat of 1995 and 2000. So strap yourself in for a great time because it won't be anything like the frustrating trip we had last fall. Simply put, if temperatures are normal or cooler than normal it should be an incredible rut.
To recap what is found on the 2003 Deer and Deer Hunting calendar, expect to see the following phases of the rut if the whitetail herd is not burdened by rut suppressors like warm weather, poor adult-doe-to-antlered-buck ratios, human pressures and baiting.
Seeking Phase: Minor-Oct. 7 thru 14; Major-Nov. 6 thru 12
Chase Phase: Minor-Oct. 15 thru 21; Major-Nov. 13 thru 19
Breeding Phase*: Minor-Oct. 22 thru 28; Major-Nov. 20 thru 26
Seeking Phase: Minor-Nov. 6 thru 12; Major-Dec. 4 thru 11
Chase Phase: Minor-Nov. 13 thru 19; Major-Dec. 12 thru 17
Breeding Phase*: Minor-Nov. 20 thru 26; Major-Dec. 18 thru 26
* Note that this is the peak of the breeding phase. There will be slightly less breeding on three days either side of this time frame.
One of the major reasons for conducting our research is to help hunters know when they need to be in the woods. Another is to inform hunters of the kind of strategies they should incorporate into their hunt.
During the seeking and chasing phases of the rut concentrate on areas that experience the greatest deer movement. During these two phases bucks will be covering a tremendous amount of territory, in many areas up to 4,000+ acres. Setting up in prime travel corridors, funnels and pinch points should offer the greatest opportunity of ambushing a wary buck. It's in these locations that a tremendous amount of scraping and rubbing will take place. Strategies, like calling and rattling should shine during this time.
When the breeding phase of the rut kicks in it's time to concentrate on hunting doe groups because this is where the bucks will be. The hunter who becomes adept at using a grunt tube will have a great advantage during this phase of the rut.
A more detailed look at this research and the hunting strategies based on its results can be found in my book Hunting Whitetails by the Moon, which can be purchased by sending a check or money order in the amount of $24.50 to the following address:
4730 County Route 70A
Bath, NY 14810