Wisconsin's War on Deer Management – Part 2
The discussion and drama following Wisconsin’s disappointing deer hunting season and the debate about the future direction of herd management continues to grow as the 2014 gun season saw a 15-percent decrease in harvest from 2013.
In Part 1 of “Wisconsin’s War on Deer Management,” we organized the scattered facts and statistics into one source to get everybody on the same page. Now it’s time to discuss what potentially caused the lowest gun harvest in 30 years, and if there is reason for the mass panic we are currently seeing in the Badger State.
The Numbers Don’t Lie
Gun license sales in 2014 dropped four percent from 2013. Though four percent doesn’t sound like a significant decrease, that drop equates to nearly 25,000 license holders. If we assume that those 25,000 license holders had a 30-percent success rate (hunter success was about 32 percent in 2014), then there would have been another 7,500 deer harvested in 2014. These 7,500 deer would have brought the total harvest closer to the 200,000 mark but certainly doesn’t explain the staggering drop in harvest. So what other factors might have influenced the decreased harvest?
The winter severity index (WSI) is a measure used by biologists to gauge how tough the past winter was on a deer herd. The Wisconsin WSI is calculated by adding the number of days where 18 inches or more of snow is recorded to the number of days where the minimum temperature is 0 degrees Fahrenheit.
These totals are then tallied across the entire winter season. Although the criteria for his method is somewhat subjective, it does give biologists a way to track the potential influence winter has on a deer herd. As hunters, we need to fully understand the impact of winter. During a very severe winter (WSI ≥ 100), much like those experienced in the Northwoods during 2013 and 2014, a herd can see up to a 30-percent mortality rate, which is a huge number!
This high mortality rate is alarming, but remember this is Mother Nature’s way of balancing over populated deer herds with the amount of food they have available. Obviously, these high mortality rates have more of an impact on a deer herd that isn’t over populated and is part of the reason why harvest numbers were down in 2014. In an attempt to combat these severe winters, the DNR reduced antlerless permits, which also likely influenced the declining deer harvest.
The good news is there is hope for 2015 as this past winter was literally “half” as severe according to the WSI. The milder winter should lead to less winter kill, which should equate to a greater number of healthy deer for this upcoming fall. Hunters also will see benefits caused by the past two severe winters. There will likely be an abundance of food for deer due to increased winter mortality in 2013 and 2014. This could potentially mean that there will be an increased recruitment of fawns this summer as mothers will have an abundance of food available during pregnancy which means that hunters will have more deer to hunt in the immediate future. It also likely means that hunters will see improved body weights and antler size of bucks this fall as they too will have an increase in food this spring and summer.
One of the hottest topics in Wisconsin, and in the country for that matter, has been the effect of predators on local deer herds. One of the largest research projects in the country looking at fawn survival has been ongoing in Wisconsin since 2011.
The two study areas being examined are in the east-central Farmland and the Northwoods regions. Not surprisingly, predation has been the number one source of fawn mortality in the Northwoods. Survival has varied from a low of 22 percent to a high of 52 percent. At those lower survival rates, you can see why deer herds are not replenished after the previous hunting season and recruitment can be additionally influenced even more after a severe winter.
For example, when fawn survival is only 22 percent, then about two out of 10 fawns will survive to three months. Assuming those two three-month-old fawns survive until November, they are then susceptible to hunting. Assuming they then survive rifle season, they then must survive a tough northern Wisconsin winter. As you can see, life in the Northwoods isn’t easy for a deer in their first year of life.
In the Farmland region, predation was not the number one cause of fawn mortality. In fact, the number one cause was starvation and/or abandonment. However, the survival rate did not vary nearly as much in the Farmland region as in the Northwoods, ranging from 58 percent to 62 percent.
This is the type of research that is needed in order to better manage deer populations as it identifies other causes of mortality that we may not have otherwise known about. Regardless the reason of fawn mortality in the Farmland region, fawn survival rates in this region are really good and probably are one of the reasons the Farmland deer herd numbers have not dropped as severely as they have in the Northwoods.
Adult Buck Survival
The same study looking at fawn mortality in Wisconsin also is looking at adult buck mortality. So far, though no surprise, researchers have found that the number one source of mortality for adult bucks is hunting. Yes, hunters are still considered predators and have major influences on the deer herd. But the number two reason is different for the Farmland and Northwoods regions.
Since 2011, vehicle collisions were the second source of mortality for adult bucks in the Farmland region. That said, there aren’t any “perks” being given to the DNR from insurance agencies here, those are completely myths. Remember, the Wisconsin DNR’s primary funding source is hunting license sales, so why would they sabotage that?
Winter severity was the second highest source of adult buck mortality in the Northwoods. The absence of predators in the top two causes of mortality of adult bucks may come as a surprise to many of you and may leave you scratching your head. The important thing to remember is that deer are not the only food source for these predators.
For example, outside of the fawning season, black bears mainly forage on berries and natural vegetation. Generally, adult deer are too large of prey for coyotes to takedown by themselves. However, there are now reports of coyotes being able to take down adult deer. Although wolves will eat a variety of smaller animals, deer still comprise a majority of a wolf’s diet.
So how are wolves not one of the top two sources of mortality of adult bucks? The estimated wolf population in spring of 2014 came in at just under 700 wolves in Wisconsin. If we assume that an adult wolf kills about 20 deer per year (a number reported from previous studies) that puts wolves at a yearly tally of about 14,000 deer. This number doesn’t even come close in comparison to the number of deer that hunters harvest on a yearly basis. Now we are not saying that wolves don’t have a local impact on deer herds, but in the grand scheme of things, wolves appear to have minimal impact on the overall deer herd.
Although we tend to think predators have a huge effect on the entire deer herd, aside from fawns, it is really minimal. Even with expanding wolf populations, the total mortality is a fraction of hunting, deer vehicle collisions, and winter kill. (Jeremy Flinn photo)
How Do We Fix It?
We’ve identified some of the major factors that influence the overall deer population and deer harvest, and have shown that this is a very complicated issue with many things to consider. As hunters, we have no control over the severity of a winter. We also have very little control over the declining license sales, unless we start introducing many new people to the sport.
And, yes, the DNR still reigns supreme over much of the license allocation and bag limits, though now the general public has more input via the County Deer Advisory Councils (CDACs). So what do we have control over?
Approximately 83 percent of Wisconsin is privately owned. This means that private landowners can have a huge influence on their own deer hunting by taking initiative and implementing quality habitat management practices. But how do you know where to start with habitat management? That’s now much easier to do with the help of the Deer Management Assistance Program (DMAP).
This program allows for a professional biologist to assist landowners in establishing and accomplishing realistic goals for the deer herd. The beauty of this program is it allows for a more personal interaction with biologists from the DNR. This, in turn, is beneficial because biologists now have the chance to educate landowners on why the DNR manages the way it does, and for landowners to voice their concerns and experiences directly to DNR biologists. And contrary to the program’s name, biologists will help with the management of a variety of species of animals. This program really is a win-win for both landowners and the DNR.
Wisconsin has now activated County Deer Advisory Councils (CDACs) which will provide public input on deer management regulations in their respective areas. (Jeremy Flinn photo)
What about the predators? Surely, this is one thing that hunters can help to control. Obviously, predators are eating deer, but are they really affecting the overall deer population? If hunters are seeing less deer and more predators, then predators must be the reason for the declining population, right? Although this seems like a logical answer it may not be the correct one. For example, ask yourself what other factors might be influencing the deer population? How severe have the past few winters been? When was the last time the forest you hunt has been thinned?
This last question may be the most important. By implementing quality habitat management practices, you increase two vital things needed for deer survival: food and cover. It doesn’t matter how many predators are on the landscape, there won’t be many deer around if there isn’t enough food and cover.
Additionally, hunters can conduct simple camera surveys which will give them the data they need to monitor local deer populations. This is the type of data that hunters need to make educated decisions about the level of influence predators are having on the local deer herd.
However, if you are still adamant about predator control, you must realize that opportunistically shooting predators during a deer hunt won’t do much good in the overall scheme of things. Rather, trapping is the more efficient method of predator control. With all this being said, predators are here to stay. We, as hunters, need to learn more about the interactions of predators, deer and their habitats to more effectively manage all three.
We’ve talked a lot about quality habitat management practices, but what exactly do we mean? Food plots are the first thing that comes to mind when most people think about habitat management. Yes, supplemental food plots can be incorporated into a habitat management plan. But what we are really talking about is timber stand improvement (TSI).
TSI includes multiple methods such as selective timber harvest, hinge-cutting and/or prescribed burns. All of these methods will help to improve habitat quality by creating better fawning cover which will help fawns escape predators and also will create valuable native foods like woody browse.
Native foods are what deer depend on throughout the year, and particularly during those hard winter months. By creating high quality thermal cover, such as spruce, pine and cedar thickets and providing abundant native food through implementing TSI, deer will have a better chance at surviving a severe winter. However, we do recommend consulting with your local biologist and forester before implementing large scale TSI. Unfortunately, there isn’t much else that can be done when winters are as severe as they have been the past few years. Luckily, those winters don’t occur year in and year out.
The positive news is there are things hunters can do to improve their deer hunting. The negative news is it sounds like a lot of work and that’s because it is. Just like anything in life, if you want the best of something you are going to have to work for it. Quality deer hunting is no exception.
As hunters, we can’t expect to have our cake and eat it too without putting in the work. This may mean that we need to be honest with ourselves about our goals for deer management and the amount of work we are willing to do to accomplish those goals. However, the most important thing to remember regardless of the goals you set for yourself is to have fun.
Rifle hunting in Wisconsin has a rich history; it’s a history full of memories of going to hunting camp, being with friends and family and having a chance to get away from the real world for nine days. In many ways, this is even more important than harvesting a deer and is something that we should never let go.
Yes, deer harvest was down in 2014, but this is a trend that many Midwestern states experienced. The good news is this trend is reversible but doing so will take a lot of work. As hunters, we can start to reverse this trend by directly working on the landscape to improve habitat as well as working with our neighbors and DNR biologists.
We need to remember that when working with neighbors and biologists, communication is a two-way street and we must do our part to be effective communicators. We will never reach the full potential of deer hunting in Wisconsin unless we all work together. Balance is the one thing people, animals and habitat all seek in order to thrive.