The Science Behind Low Deer Numbers

Wildlife biologist and longtime deer hunter Dave Samuel explains the science behind why so many hunters are seeing fewer deer during the last few hunting seasons.
The Science Behind Low Deer Numbers

After the 2014 deer season, listening to talk in the local sporting goods stores in my home state of West Virginia, you’d have thought that there were no deer left. The comments started during the bow season. But after the DNR released preliminary data showing that the buck firearms kill was down 34 percent from the previous year, things really heated up. The 2014 kill was 37,277 bucks compared to the 2013 harvest of 56,523. I admit that a 34 percent drop is big, but does that mean the deer are gone? I don’t think so.

Of course there were hunters complaining that the DNR doe harvest quotas had wiped out the deer. We hear that every time there is a big one-year drop in the buck harvest. Not just in West Virginia, but everywhere. And during the West Virginia bow season I heard hunters talking about seeing fewer deer than they “normally” see. I believe their perceptions were true. I believe that lots of hunters did see fewer deer last fall, not just in West Virginia, but in parts of other states as well. But it wasn’t because there were fewer deer.

In years when the acorn mast is high, as it was this year in many areas, hunters see fewer deer. And when fewer deer are seen, fewer bucks are harvested. Acorns everywhere means the deer are scattered. They don’t have to go very far to find food (i.e. acorns), and when deer move less, hunters see fewer of them.

At the local level, other factors can play a role in deer harvests. Obviously weather is one. Extremely warm weather, heavy rains, and even very high winds can curtail the overall harvest, especially if you get those conditions the first couple days of the gun season. Weather aside, the real culprit here in West Virginia this year was a huge acorn mast.

Take Our Poll: Have You Seen Fewer Deer Over The Last Couple Seasons?

What that lower buck harvest means is that next year the harvest will contain a higher number of older bucks simply because they survived another year. That’s the take home message. Some will disagree, and the proof of my theory won’t really be known until the end of the coming year’s buck season.

That’s the situation here in West Virginia and parts of other states that had low acorn mast in 2014, but that isn’t the problem in other Midwestern states. Everything is not rosy in deer country.

Over the past 30 years we’ve watched deer numbers climb to heights never seen before in many of the states that hold whitetails. The peak occurred in the mid 1990’s and in response those states increased the bag limit for does. We’ll look at doe harvests in a minute, but regardless of the reason, hunters from Minnesota to Missouri and Iowa to Ohio are starting to vent their displeasure with their state deer managers. They aren’t seeing the numbers they once did and complaints are on the rise. Let’s look at some numbers and try to provide possible answers to explain lower deer harvests.

Illinois hunters are becoming very vocal relative to the decreased lack of deer sightings during the hunting seasons. The antlered buck harvest reflects that decline. In 2011, Illinois hunters harvested 70,513 bucks. According to a Quality Deer Management Association (www.qdma.org) survey, in 2012 that dropped to 69,681 (obviously not significant) followed by another drop to 57,769 in 2013. Meanwhile the antlerless doe harvest showed a decline, starting with 110,938 in 2011 then down to 90,845 in 2013.

The total deer harvest in 2013 was 148,614, and this dropped to 145,804 in 2014.  Going back to 2007, the buck harvest was 81,356 and the total deer harvest was 199,606. Yes, things have changed in Illinois.

The 2011 deer harvest in Minnesota was 192,500. The 2012 deer harvest was 186,634 and the 2013 harvest dropped 172,781. Data are not final for the 2014 deer harvest but one estimate puts it at 127,000. A lower number was expected because of new hunting restrictions on harvest, but this drop has hunters complaining. The kill in 2007 was 260,000 giving hunters a further perception that things are bad.

The 2011 Missouri buck harvest was 114,011 and the 2012 harvest bumped up to 120,549. But in 2013 the harvest dropped 13 percent to 104,815. As in some other states the 2014 went up a bit to 114,152, while the total deer harvest was 260,552. The 2007 deer harvest was a tad over 300,000. Yes, things have changed in Missouri.

Iowa showed a similar pattern. The 2011 buck harvest was 46,212, and in 2012 it was 47,927. The 2013 buck harvest was 39,447, an 18 percent drop, but it bumped back up to 44,512 in 2014.  The doe harvest has dropped considerably since 2011 when it was 75,195. By 2013, the Iowa doe harvest was 59,953 and 47,131 in 2014. The 2007 deer harvest totaled 146,214, while the harvest dropped to 91,643 in 2014. Yes, things have changed in Iowa and there might be many reasons for this, but two factors definitely played a role.

First, licensed hunters continue to decline. Secondly, regulation changes were made. For example, in 2014 the deer harvest in 27 northwestern counties was restricted to bucks-only during the first season shotgun.

Complaints of decreased deer sightings have increased in recent years in Ohio. The 2011 buck harvest was 81,721, and was 81,149 in 2012. Total 2014 season numbers aren’t in as I write this, but the buck harvest during the seven day 2013 gun season was 75,408, but dropped 13 percent to 65,485 in 2014. Considering that the 2007 deer harvest totaled 232,854 while the 2013 harvest was 190,603, perception by some hunters is negative.

The Wisconsin 2014 gun deer season kill was 191,550, down eight percent from 2013. In 2007 the deer harvest was 517,573 and this dropped to 342,631 in 2013.

Obviously weather plays a role in deer harvests, especially when it’s bad during the first few days of the gun season. And there can be other local factors causing lower deer sightings and harvest in areas you hunt. Changes in habitat as forests are cut to plant more corn, high hunter numbers on a local piece of ground are local factors that the state wildlife agency cannot control.

But there is a bigger picture here. Historically, most Midwestern states reached peak deer numbers in the mid 1990’s, and most biologists felt (with some science to confirm their beliefs) that these numbers were just too high when trying to maintain quality habitat. Thus, states increased doe harvests to bring herds down. They had to do this. The growth had to end sometime.

More liberal doe hunting persisted until 10 years ago (or in that vicinity). At that time the trend in the Midwest was still greater for antlerless harvest opportunities, but that began to change. In the past five years that trend has reversed with less antlerless hunting opportunities.  According to a Quality Deer Management Association survey most of the Midwestern states are trying to stabilize or increase deer numbers. Only Indiana is in a decrease mode. Ohio, Kentucky, Illinois, Iowa, Missouri, and Kansas are trying to stabilize herds, while Nebraska, South Dakota, North Dakota, and Minnesota are trying to increase herds. (No data available for Wisconsin).  

Regulation changes definitely play a role in deer harvests, but they do not fully explain declines and I suggest that such declines are complex and can’t be blamed on one factor. There are several factors affecting deer numbers in our ever-changing world. One obvious factor is that hunter license sales continue to decline in most states. For example, Wisconsin showed a four percent drop from 2013 to 2014. Fewer hunters will kill fewer deer and license declines will probably continue in most states for years to come. 

Then there is this disease thing. Chronic wasting disease, though not yet killing many deer, has definitely influenced harvests. In areas where we get CWD, regulations and restrictions on hunters change. Hunter numbers decline, at least for a while, and in states with CWD, such as Wisconsin, it makes deer management a complex phenomenon at best.

Since 2007, Epizootic Hemorrhagic Disease has become a player in local areas. States such as South Dakota and Nebraska suffered large losses in widespread areas, while states such as Illinois and Iowa suffered large losses in localized areas. EHD mortality is very hard to measure and we know that herds will bounce back in areas hit by EHD. Even so, EHD can impact local harvests and hunter participation. 

Let’s look at the weather as well. Nasty, brutal winters have been problems in the past seven years in states such as the Dakotas and Minnesota and summer droughts have also occurred. These droughts not only affect vegetation, they exacerbate EHD by providing better breeding success for the biting midges that infect deer.

Then we have a whole new scenario with coyotes. Though probably not a factor as yet in most of the Midwest, there is a growing concern in the East and Southeast about coyotes impacting fawn survival. Ohio is now looking at the coyote situation, and coyote sightings there have grown rather substantially in recent years. You can expect to see further research on coyotes in other states. Add bobcats to the mix in the Midwest. They do eat some fawns and bobcat numbers are now at an all-time high. 

Finally, just when we think we have some idea on what affects deer harvest, consider what is happening in Kentucky. In 2011 their deer harvest was 98,756. In 2012, that jumped to 144,409. The 2014 deer harvest was still up there with 138,899 even though the acorn crop was rated as fair to poor and the weather was downright poor the second week of the firearm season. 

This example shows that the causes for ups and downs in deer numbers are not as simple as some hunters believe. My guess is that we’ve probably taken too many does in some parts of the Midwest, but state agencies apparently are working hard to correct that. However, if hunters are expecting to see the numbers of deer they did in the mid-90’s, then they will be disappointed, as numbers were too high at that time. 



Discussion

Comments on this site are submitted by users and are not endorsed by nor do they reflect the views or opinions of COLE Publishing, Inc. Comments are moderated before being posted.