Part 2: Lessons Learned from the 2016 Deer Rut
December 06, 2017
Last month, I discussed what made 2016 one of the most frustrating whitetail seasons of my career. In retrospect, it was a perfect storm in which multiple factors (some varying by geographic region) colluded to make the season a special challenge.
I pointed out that deer continue to be in poor physical condition in many areas, due to years of overpopulation. To make matters worse, many came out of a challenging 2015 winter in very poor condition. Then climatic and astronomical conditions added fuel to the fire. Climatic conditions negatively affected forage conditions and the mast (acorn) crop in many areas. To make things even worse, full moon timing, a blue moon and three super moons threw deer off their normal cycles. Abnormally high temperatures during hunting season also suppressed daytime movement.
Whitetails will gladly "answer" our questions about them, provided we ask the right ones. And paying attention to key factors throughout the year will help us formulate the right questions. It was true last year, and it will be true in '17 as well.
The successful hunter spends as much time as possible in the woods, noting what's going on with the habitat and the deer herd. It all begins in spring, when deer are just coming out of the winter stress period. The physical condition of deer immediately after winter can tell us a great deal about what will happen the next hunting season.
I begin my annual data gathering by looking at two key indicators: fawn survival and body condition of bucks. Let's delve into those individually.
Most regions (particularly the upper Midwest) still have very high fawn crops. We measure the fawn crop in October, and it's expressed as a percentage: the number of fawns per 100 does. Fawn crops of 80 percent or higher aren't unusual for many states and regions. Yet some of these same areas now are seeing true recruitment rates (yearlings produced per 100 does) as low as 15 percent. In those places, we're losing a lot of fawns between early fall and early spring.
The best way to determine recruitment is to place trail cameras strategically (over bait where legal; on trails where not) around your hunting territory in March or April. We run our cameras for two weeks during this time, then count the number of photos of does and "coming yearlings" (fawns approaching a year of age) to obtain a percent recruitment.
For example, suppose we had four cameras taking photos during the last two weeks of March. They yielded 341 images of does (being sure not to count shed bucks) and 67 of coming yearlings. Dividing 67/341, we obtain an estimated recruitment rate of 19.6 percent. That's pretty low recruitment.
Such data tell us two things. In the short term, we now have a reliable index on the impact of winter; low recruitment often means heavy winter stress. In the long term, a low "freshman class" will translate to fewer mature bucks being available three or four years down the line.
Our next key indicator is the condition of bucks coming out of winter. If, for example, in March you see and/or photograph bucks that have very poor hair coats and thin bodies, it confirms what low recruitment is telling you: Winter stress has the potential to affect the next hunting season. Whether it will have a major impact is determined by growing conditions in early spring.
If you have a late or unusually dry spring, bucks will have a tougher time recovering body condition and growing quality antlers. In areas where we depend too heavily on agriculture to help deer recover, late planting of crops such as soybeans and corn also can have a negative impact.
Over the past three years I've traveling about the northern U.S., looking at forage conditions in farm country. As a result, I'm concerned about the devastation that years of over-browsing have visited on native forages. Many agricultural crops are only present for 4-5 months of the year. This leaves deer to find additional nutrition in the woods and "stringers" of woods surrounding fields. Of course, food plots are helping to counter this problem.
The combined impact of high winter stress and poor spring nutrition is that does will have to work harder to nurse their fawns, leading to poor body condition after weaning. In preparing for fall, all deer have to do the following things in correct order: 1. replace lost reserves after summer; 2. store white body fat to carry them through the winter; and 3. shed the summer coat and grow the winter coat (requiring a huge amount of protein and energy). Bucks must finish growing and mineralizing their antlers and build muscles critical for combat. That brings us to the next set of questions.
As discussed last month, available energy is the single most important limiting factor to whitetails. Energy can be found in many forms, but certain forages and fruits are most important. In the South, one of the most important late summer energy foods is American beautyberry, a shrub that produces an abundance of purple berries in August and September. It's one of the few native plants bearing fruit at this time of year. These berries often are the highest energy food source at this time.
In agricultural areas, maturing crops of corn and beans also provide an abundance of digestible energy. I prefer to make many trips to my hunting territory in late summer to assess the availability of energy foods. I also have permanent walking transects over which I travel to develop an assessment of acorn production potential. Walking along the same trails each year, I stop periodically to examine the limbs of oaks, using binoculars. You can just record the relative abundance of acorns (absent, light, moderate or heavy), or count the numbers of acorns on randomly selected limbs. Either way, you obtain an index of acorn production.
We conduct another trail camera survey in late summer to determine several demographic metrics (age, sex, fawns, etc.), along with the overall body condition of bucks and does. If deer are in good condition, they'll be shedding the summer coat and growing the winter coat at the same time. Images of some deer with grayish coats and others in worn summer coats is an early warning of poor fall condition.
As noted last month, deer must perform certain physiological activities in exact order. For instance, a doe won't come into estrus on time if she's late in recovering her body condition after summer. I assure you a herd with does in highly variable physical condition in early fall will translate to a trickle rut.
MOON & WEATHER
There's nothing you can do about moon phases or climatic conditions, obviously. But there's still value in paying attention to how they might impact deer.
I keep a long-term moon phase calendar on my computer, so I can easily determine when the full moon will occur for each month. Whitetails would "prefer" to breed ±3-5 days about the full moon related to their geographic race. They prime their systems on the harvest moon (full moon in September), then coordinate breeding on a subsequent moon. Avery Island whitetails (native to Louisiana and the upper Texas Gulf coast) key on the hunter's moon in October; Midwest deer on the beaver moon in November; and South Texas and Mexico deer on the winter or frost moon in December. More and more, however, many whitetail populations are becoming less predictable in their rut timing.
But there's a caveat to the full moon priming of the rut. To the average hunter, the term "rut" doesn't mean when a large percentage of does come into estrus and are bred; rather, it refers to the "chasing" phase, when bucks are running over the landscape trying to find willing does. I love to rattle, yet learned long ago the best time for rattling is about a week before the chasing time. After that, mature bucks find receptive does and greatly restrict their movement. At such times, they definitely aren't interested in fighting.
I subscribe to government websites that report and predict climatic conditions for specific geographic areas. One of these is the USDA Drought Monitor official site (droughtmonitor.unl.edu/), which is updated weekly. If you'll study this online map, you can get a feel for the conditions you might be facing during the season.
A CUSTOMIZED HUNTING PLAN
I love hunting with my friend Larry Porter of Ken Tenn Hunting. He does an incredible job of managing both the habitat and the deer. As the '16 Kentucky gun season opener approached last November, Larry kept me informed as to what was happening with deer movement and activity, including forwarding me trail camera photos of some great bucks on the farm I'd be hunting.
In this situation, you'd assume I'd have no problem killing a trophy buck. Yet here is what I knew going into the hunting season:
* Deer were coming off a very droughty spring and summer.
* I'd learned from earlier trips to Kentucky that the acorn crop was spotty at best.
* The full moon would be on Nov. 14, and it would be a "supermoon" (much closer to earth than normal, and thus much brighter).
* The season opener would be Nov. 12, designed to coincide with the rut (breeding).
* Temperatures for the season's first week would be well above normal.
For these reasons, I predicted a trickle rut that had no peak but a great deal of nocturnal movement, due to more moonlight and higher daytime temperatures. With the full moon on Nov. 14, two days after the opener, some of the bucks would be tied up with a handful of estrous does. As the acorn crop wasn't reliable, I reasoned the Buck Forage food plots would be very popular. So I decided to focus on hunting the food plots and built brush blinds to favor the wind. Rattling would be out of the question, as the chasing time had already occurred.
Opening day was a disappointment, as we saw only two yearling bucks. I was concerned that we didn't see any does. That night Larry's trail cameras caught two monsters feeding on the plot between 1:00 and 2:00 a.m., but that wasn't exactly helpful. Each day produced the same results, and every night the bucks were frustratingly feeding near my blind. Not a single time was either buck with a doe.
On opening day the full moon rose at 4:37 p.m. and the sun set at 5:32 p.m., making it possible for deer to wait past shooting light and taking advantage of the rising full moon. Having only a week to hunt, I surmised that if I were to have any chance, there would have to be an appreciable time between the onset of darkness and the rising of the almost full moon. That would provide a lag time for the deer to adjust to changing light conditions.
To shorten the story, it boiled down to my last two days: Nov. 17-18, when the moon would rise at around 9:00 p.m. By then we already were noticing signs of an activity shift, as we'd begun to see immature bucks coming to the plot around midday. I knew deer would begin to feed on the plot just at sunset to "stock up" until light conditions improved. (Whitetails are slaves to their rumen and need to feed every 3-4 hours.)
The first evening produced a 3 1/2-year-old 10-pointer that came in to feed on the oats. Two does were there already, and they ran away when they saw him. But nothing bigger showed up. Now I was down to one day of hunting, and things weren't looking good.
The 3 1/2 came in earlier than the previous day and fed for a half-hour or so. Then, just as we were about to lose shooting light, I saw a larger-bodied deer along the edge of the plot. The 3 1/2 looked up and stared. Was it one of the bucks I'd been waiting on?
This new deer stopped at two scrapes and worked them slowly. By now, light was fading fast. When he finally walked in to the plot, it was obvious he was quite old, probably 7 1/2 or more. He had impressive bases, but just seven weak points on short beams.
Now I was on the "horns of a dilemma." Should I shoot him, or wait for one of the big guys I knew were there? I decided to wait . . . and lost. Darkness came without either of the bigger bucks showing up.
We were taping this hunt for North American Whitetail TV presented by Quick Attach, and the goal always is to show a representative deer being taken. Still, I'm satisfied I made the right decision to let that buck walk. What need is there to kill a deer just to make TV? I've learned our viewers are experienced hunters who appreciated my decision. Deer hunting on TV is as much about the experience as it is the deer.
In Kentucky, waiting until the moon rose later in the night and hunting a reliable food source eventually paid off with an opportunity at a mature buck. In retrospect, I could have elected to move farther into the woods to take advantage of bucks staging downwind of the food plot. That might have resulted in my getting a shot at one of the other mature deer in the area. But that's a difficult choice to make when shooting TV, because the video cameras can more easily pull in light in open areas than in the woods.
Although I didn't fill my tag, this rut hunt from last November illustrates the thought processes I feel you should use in deciding where and when to hunt. The more information you have about the deer herd, food availability and climatic conditions, the better decisions you can make about hunting strategies. Oh, and studying up on deer behavior never hurts.
It's one thing to understand what's going on with your deer herd, but it can be quite another to do something about it. That said, we all should try to develop hunting plans that take current environmental and herd conditions into consideration.