Few periods of a deer’s life are as important to hunters as that reproductive time commonly called the Rut. It is the subject of much discussion, anticipation and study. It is the one time each year when hunters have a better-than-average chance at seeing and harvesting a trophy buck. But do you as a hunter know how to best use the collective research to kill the trophy of a lifetime? The woods are full of deer sign in the fall. Much of this sign deals with deer as they enter the rut. Knowing and properly interpreting these signs can make the difference in success or failure. Sorting out all the variables is a little like a computer flow-chart, with dozens of “if-then” blocks to consider. In the end the solution is there, right before your eyes.
Mississippi State University has one of the most-respected whitetail research programs in the United States. And each year graduate students and resident researchers compile data to add to the growing cannons of knowledge about Mississippi’s number one big-game animal.
Here are a few of the factors that come into play when the rut kicks in:
Photoperiod, Genetics and Climate
"The length of the daylight hours is the key that triggers the hormonal response in does, and thus kicks off the rutting period," said Dr. Bronson Strickland of Mississippi State University. "Genetics then come into play as a contributing factor. This is to say that does in a given area are hard-wired to enter estrus based on a set of given criteria."
Research at MSU continues to investigate and document those factors that affect the rut, including climate and overall health. Nutrition, as well as doe-to-buck ratio, also come into play.
Strickland pointed out that the rut in the northern portion of North America begins sooner in the calendar year than it does in the more southerly areas. Even deer in Mississippi display variances from north to south of as much as a month.
See the accompanying map for a breakdown of how the rut plays out across the state.
Now that we have a basic understanding of what triggers the rut, what are the definitive signs that bucks and does are about to have an intimate encounter? And how does Ms. Whitetail let Mr. Whitetail know when and where she wants to rendezvous?
Billboards in the Woods
"Rubs are some of the first sign of deer activity a hunter will see in the woods," said William McKinley, a MDWFP deer program biologist from Kosciusko. "A buck will use its antlers to strip the bark from a small tree, or several small trees. This is little more than the buck saying ‘I was here’ at a given point in time.
"Generally, the bigger the tree used for the rub, the bigger the bucks antlers, but this not an iron-clad axiom."
McKinley said rubs begin to appear as velvet dries and does not indicate the rut is beginning. However, later in the season — as the rut truly begins — bucks will continue to rub, leaving their calling card, so to speak, for other deer to see.
Strickland referred to these later rubs, made in association with scrapes, as a sort of ‘billboard’ announcing that the buck is there.
Research at MSU has not documented a quantity of rubbing activity by Mississippi bucks, but studies by Dr. Karl V. Miller at the University of Georgia indicate a mature buck may make as many as 1,000 to 1,200 rubs a year.
Playing in the Dirt
This magic time known as the rut has many facets that may seem curious to humans but are serious business to deer. These include the buck’s use of glands to advertise his presence and the doe’s willingness to be bred.
"The breeding activity centers around a scrape or, more accurately, a series of scrapes," McKinley said. "The rut is a bell curve, with a few females entering estrus before the greatest number — or peak — and a few entering after the peak. These few (deer) may give hunters the false impression the rut is early or late, depending on specific observations.
"But as the curve indicates, there is a high point when the greatest number of does enter estrus at near the same time."
According to Strickland, bucks create a scrape with their feet, placing scent in and around the scrape by several means.
The act of pawing the scrape leaves scent from the inter-digital gland between a deer’s toes. The same buck will then lick a branch overhanging the scrape, leaving scent from his saliva – he may also rub the limb with his pre-orbital glands near the eyes, and make a nearby rub, leaving additional scent.
But he isn’t through with his ‘billboard’ just yet: He also will squat over the scrape and urinate, allowing the urine to flow over his tarsal glands and onto the scrape.
The female then uses her keen sense of smell to locate these scrapes, and she urinates in them, as well.
As McKinley said, this is when the fun begins.
Bucks have a gland in the roof of the mouth known as a vomeronasal organ. In a posture called a ‘lip curl,’ it is used to sniff or taste doe urine to determine the stage of estrus.
This all may seem very technical and lost on the hunter, but how it benefits the hunter is coming up soon.
Bucks will make the circuit of their scrapes (and other bucks’ pawings, as well), checking for a ready doe. If the wind is right, and the buck recognizes his scrape has not received a visit from another buck or a doe, he may move on without actually coming to the scrape.
If another buck has been there or a doe has visited, he may come in to investigate more closely.
This indicates to the hunter the importance of having a commanding view of that area downwind of an active scrape.
Once the buck senses a doe is about to reach her peak, when she will stand and allow herself to be bred, he will pursue her tirelessly, perhaps for several days.
It is during this time that bucks start to drop their defenses somewhat and move out of their daily routine by extending travels out of their core area and during daylight hours.
The hunter will best benefit from hunts that stretch from pre-dawn to sunset.
"Every year I hear stories of the savvy hunter who waited that extra hour before breaking for lunch or remained in the stand through mid-day and killed a buck as it ambled along checking scrapes," McKinley said. "And most of these were not from shooting houses on food plots, most were in transitional areas such as the edges of fields, cutovers or along logging roads."
Loose Women and Traveling Men
According to MSU research, once a doe nears her peak, she may have any number of bucks of various ages following her at the same time. Since doe are social creatures and tend to hang out together, it is not odd for several doe to enter estrus at the same time, thus increasing a buck’s chance to score.
"Bucks work out the pecking order," Strickland said. "Dominate bucks will chase away subordinate bucks, but they may not go far, and while ‘The Man’ is tending a doe, the No. 2 man will be making time of his own.
"When a doe is ready to stand and be bred, she will stand for the buck that is nearest at the time — be it an 18-month-old spike or a 5-year-old wall hanger."
Strickland added that, once a buck has bred a doe, he is done, at least for a day or three.
Meanwhile the doe will take on all comers. Studies indicate does frequently have multiple partners, and 25 percent of the time twin or triplet fawns born to a doe have different daddies.
According to McKinley, an MSU study at a 3,000-acre enclosure indicated the hottest buck making the most fawns was a 3 1/2-year-old 8-point, even when the pen contained much larger and older bucks.
Another interesting point made by McKinley is the phenomenon among bucks known as a rutting excursion. Based on several studies, mature bucks will sometimes travel several miles outside their home range to breed, and then return to their home range a few days later.
For this reason there has to be some question about the wisdom of harvesting "management bucks" on open range.
The bottom line is hunters wanting to kill a buck need to be in the woods as much as possible during the rutting period.
The Sound and the Fury
"There is no doubt in my mind that vocalizations are an important part of the rut," Strickland said. "I’ve used a soft grunt call to bring bucks into shooting range, and other times bucks have just ignored them.
"Bucks grunt when following or tending a doe, and while breeding. They also produce grunts when establishing dominance. The grunt-snort-wheeze is a sign of dominance — a way of saying ‘I’m the biggest, baddest buck on the branch.’"
And that’s why it’s important to use this call sparingly.
" Hunters who are too aggressive in using this call may actually drive away some bucks," Strickland said.
He added that calling puts a buck on alert — he will come in with eyes scanning, and nose and ears on alert for the other deer.
So while calling might mean you see more deer, it also increases the chances you might get busted.
Strickland also said no research data at MSU indicates that does use vocalizations during the rutting process. He was quick to point out that doesn’t mean they don’t; it’s just that MSU has no data to support that they do.