September 22, 2010
By Dr. James C. Kroll
EVALUATING YOUR MANAGEMENT PROGRAM
In the last issue, I discussed how confusing the term "deer management" can be. I talked about the three important aspects of managing whitetails -- people, habitat and populations. Each has to be addressed in order to succeed, and this truth has been pointed out in many articles. In addition, I added a very important fourth component: a well-defined, measurable goal. Without a clear goal, you'll never succeed.
Unfortunately, many private land- owners and state agencies have non-existent or poorly defined goals. And in spite of being the most popular game animal in North America, that's what makes whitetails also the most poorly managed! Many landowners and hunters alike are becoming disillusioned with management since they are not seeing the progress in buck quality they had anticipated. If you fall into this category, this installment will show you how to go about diagnosing your current situation so that you can arrive at a prescription for success.
RELATED: What Is Whitetail Management, Part 1
WHERE ARE YOU NOW?
The best place to start analyzing your management program is to let your deer tell you what's going on. That's where all the records you've been keeping come into play. A healthy deer herd has the following characteristics:
1) A high recruitment rate of at least 70 percent.
2) Balanced buck age structure.
3) Doe age structure favoring younger age-classes.
4) High age-specific antler quality.
Remember that recruitment is the percentage of fawns born in any given year that are still alive one year later. In most areas (except southern Florida) this means June. It doesn't matter how many fawns are born if only a handful reach one year of age.
Using infrared-triggered cameras, Ben Koerth and I normally conduct two camera censuses on a property: one in early fall, another in late winter/early spring. The early fall census gives us a good idea of:
1) The fawn crop from the summer.
2) The age structure of bucks and does.
3) Antler quality assessment.
START WITH THE DOES
From an aging standpoint, does should be placed in the following categories: fawns, yearlings, mature (2 1/2 to 4€‚1/2 years), and over-mature (5€‚1/2 years plus). You really don't want any over-mature does in your herd. Why? If you are doing a good job of recruiting high-quality bucks, you want their daughters to be the primary breeding does. That's how you improve the most difficult component to management: genetics.
Ask yourself this question: "If I have an 8-year-old doe on my property, what was I doing nine years ago?" Younger does will be your best breeders, and they tend to have sons with larger antlers earlier in life. I do not know why, but that has been my experience. Furthermore, in well-managed herds, a high percentage of doe fawns will breed on the second estrous cycle, and the majority of their offspring will be bucks!
Bucks can be aged with reliability to the year most of the time, so we prefer to use the actual estimated age. However, you also can place them into the following general categories: fawns, yearlings, immature (2€‚1/2 to 3€‚1/2), mature (4€‚1/2 to 5€‚1/2), and over-mature 6 1/2 plus). Although there has been a lot of press lately about all ages of bucks breeding, there is no study to date that supports the idea that mature bucks do not contribute a larger share of offspring.
Thirty-five years of experience has taught me that although all age-classes do indeed do some breeding, in a balanced-age buck population the "breeding pool" pretty much is limited to the mature bucks. The accompanying graph illustrates how the age-class distribution of a well-managed buck and doe herd should look.
ANALYZING ANTLER QUALITY
The next thing to study from your fall camera census is the quality of antlers by age-class. In even the best-managed herds, 2-year-old bucks usually grow 8 points, although there is not a great deal of predictability between a 2-year-old's antlers and what he will have at maturity. So that means that the 3-year-old bucks should be the first age-class that we want to seriously evaluate.
We add up all of the 3€‚1/2-plus-year-old bucks that have 8 or fewer points and those that have 10 or more (9-pointers are considered as 8-pointers). Then we calculate the ratio of 8-point to 10-plus-point bucks. If the ratio is not even or is in favor of the multi-point bucks, there is a problem. It might be nutrition or it might be genetics. Some geographic areas just seem to have 8-point genetics, and there is not a whole lot you can do about it. Nutrition, on the other hand, can be improved, and I will discuss this aspect later.
Don't expect more than your deer can deliver. Our landmark antler study clearly showed that the average mature buck "wants" to have 8 points and a B&C score of about 130 inches. Anything over that is a real plus, no matter where in America you hunt. Our data also showed that the chances of a buck fawn ever breaking 150 inches is about 12 percent. So it's best to use the average as a standard against which to judge your program.
LATE WINTER/EARLY SPRING CAMERA CENSUS
This is the most important camera census. Your photographs will tell you how many fawns survived the winter and how many bucks survived as well. Study the body condition of your bucks. The shape a buck is in during March has a great deal to do with what kind of antlers he will produce the following summer. Body condition also will tell you something about the nutrition of your deer, particularly in regard to what condition they were as they entered the fall season. Deer will not add fat during the winter, so fall condition is critical. The target is to have a 70 percent recruitment rate, so use this as your standard.
In Part 3, we'll wrap up this series by discussing the most important aspect of quality deer management: nutrition. See you then!