November 21, 2013
In the past decade, the deer hunting world has been inundated with catch phrases like antler restrictions, age-class restrictions and all sorts of management plans.
The overall theme suggests deer hunters are solely obsessed with trophy deer. In some ways, that obsession is there. But the idea behind so many of the restrictions you read about really center on creating a healthy deer herd, and big bucks are just a residual effect.
“I always get a little miffed when I hear people refer to these management plans as a mania for trophies,’’ Dr. James Kroll said. “Bigger antlered bucks are a benefit, but the whole purpose for having antler restrictions is to increase age structure that in turn creates a healthy herd.”
Dr. Kroll, known as Dr. Deer to many, has been at the forefront of deer management for over three decades. Some might even refer to him as the father of modern-day deer management.
While some folks may view antler restriction management plans as a way to more trophy bucks, that idea is ultimately a misnomer that doesn’t matter.
“The average guy is not giving a lot of thought to degrading age structure. But the reason for having antler restrictions is to increase age structure,” Dr. Kroll said. “If you've got better age structure, you've got more genetic diversity. More genetic diversity, you've got better antlers. Other than that, you're getting to experience a lot of things a lot of hunters don't get to experience, like rattling and calling.”
Dr. Kroll points out these management plans play along with what should be occurring naturally. As in all things in the natural world, there is what scientists have termed “natural selection.” In layman’s terms we are more familiar with saying “survival of the fittest.”
In a healthy, functioning deer herd, a buck has to fight his way up the ladder to be able to breed.
“He doesn't get to breed unless he is fit,’’ Dr. Kroll said. “If you have a situation where a deer has to wait until he's four or five years old to make his biggest contribution to the herd: What has he gone through to get there? You know he's had to survive a lot of things.
“More than likely, he's gone through a one-year drought so the characteristics are there to survive that. He's done a bunch of things. He's a better fighter. He's a better everything. If you don't have that age structure, then it's a world run by teenagers. Everybody gets to breed. Even some buck fawns breed.”
When that happens the overall health of the herd degrades. While genetics can be a testy subject for a lot of people, the overall point is the entire deer herd is better off when the healthiest survive and breed. The herd works the way God intended for natural things to work.
“In a well-ordered deer herd, you have regulators,” said Dr. Kroll, espousing a good age structure with a healthy percentage of mature bucks. “That puts less stress on everybody. The bucks lose less weight.
“When immature bucks breed, it's like breeding too young a bull. If they aren’t part of the breeding, which they shouldn’t be, they don't have that physical stress put on because they're suppressed. So they can route their resources to building their body, building their antlers. You force a buck to compete a lot, and to breed a lot; his antlers are going to go down the next year.
“That’s often the case between ages four and five, because it’s a stressful time. You see more scars on a four-year-old than you will any other age. That’s a tough year for a deer, but if he’s been through three years prior to that he should be able to handle that for that very reason.”
Like a runner training months for the one-day marathon, the four-year old has been training his whole life for that year. The toll to the body is rigorous, but even more so for a young buck not quite ready physically.
“If there are older, more experienced, bigger deer out there, then he's trying to join that club,” Dr. Kroll said. “They're going to put him through a test, and haze him a little bit, to see if he actually belongs.”
There is an age-old scenario some hunters have professed for far too long: “We're shooting all these younger bucks, saving our one bull of the woods.” While arguably more of an excuse to kill anything that walks than following a management plan, these hunters are not allowing the herd to get the genetic diversity the natural world needs it to have.
Bulls have been bred through the years to breed lots of cattle. A deer on the other hand is physically set up to only breed a handful of doe.
“With deer, the more pressure you put on an individual, the more serious problems you can have,’’ Dr. Kroll said.
Every deer hunter with an inkling of interest in managing their deer herd understands the three building blocks of bigger deer are age (allowing a deer to grow to its potential), nutrition (which really translates to the abundance and quality of food in the habitat) and then genetics (the material offered from doe and buck that make a unique animal).
In many case, hunters understand that passing on a buck and letting it grow a year or two increases the likelihood of bigger antlers. They also understand food plots and managing habitat can increase the carrying capacity of the land, which means more deer to chose from, although the trend has been to offer more corn as food than enhancing high-quality browse.
When it comes to genetics, that is something most hunters simply give up on, stating it’s out of their control. In truth a big part of that building block is genetic diversity, not just introducing new strains of deer into their herd. And it goes hand-in-hand with all three of the building blocks.
When it comes to genetics, genes operate in the same way all organisms operate when it comes to natural selection. The strongest and fittest survive, so the best traits are passed on. And in layman’s terms, the extreme opposite of genetic diversity is inbreeding.
No one wants that in their deer herd. The end product, regardless if you are managing for meat or trophies, is bucks.
“It’s all about recruitment,’’ Dr. Kroll said. “You have a herd size that fits the habitat it lives on with a variety of age classes within your bucks.”
In that instance, the bucks are breeding the handful of does at its disposal, during a rut that typically lasts 7 to 10 days. When does outnumber mature bucks and the whole gang gets into the process, then that rut trickles out over a longer period. Every doe in the herd will eventually be bred, continually coming into estrus until the job is done in what it known as a trickle rut.
“The problem is when you look at the variation in birth on conception rates, it's over a broad period of time. So, on the other end of it, we have fawning period over a broad period time. What you've got is a sustained yield food supply for coyotes and other predators. You don’t have the recruitment you need for a healthy herd.
“You want those fawns to hit the ground during the same period. You overwhelm the predator then. There’s no way he can get to them all. We call that genetic swamping. The other way they just pick them off one at a time and no one survives, except the coyotes and you eventually become healthy coyote producers instead of healthy deer.”
Most of the deer hunting destination states in this country are in the north or northern part of the Midwest. Those states have a pronounced rut. The rut and fawning take place during a specific period and there is very little spillover or trickle affect. The result is age-class recruitments and a herd that is typically healthy with a good representation of older-aged mature bucks.
A big advantage for those states is hard winters that take out the weak. Winterkill may not happen every year, but systematically it knocks them back, trims off the edges, so to speak. One tenant many wildlife managers espouse is: “If the hunter won’t take care of the issues within their deer herd, Mother Nature will.”
To the north, that comes in the form of harsh winters. To the south it can come in the form of disease.
“The thing to remember is there is no one-size fits all management plan,” Dr. Kroll said. “But regardless of the site, having a deer herd that has a good representation of age classes from your yearlings on up to four and a half, five and a half, and even beyond is, is the more healthy model for the overall herd.
“It's really more about the health. The benefits are better bucks. We just use better bucks to sell, because it's a motivating factor. It's a side benefit. Everybody wants that, and if that's what we can do to get healthy, then that’s what we do.”
Dr. Deer's Camera Take
Go to 2013 Deer Camp