Deer Management In The New Era Of Coyotes

0
Fawn Survival Is Key

Hunters and deer managers face a new reality in the Southern woods. In case you haven’t heard—maybe you’re a new reader of GON—coyotes are here and having a significant impact on deer populations on some pieces of property.

It’s a story we’ve been researching and telling for years. Just how dramatic an impact coyotes could be having really came to light with an article published in the May issue of GON called “The Predator Pit.” For the first time, top deer researchers explained that coyotes, on some Southern properties, were eating enough deer and lowering deer populations so much the herd couldn’t recover, even when doe harvest by hunters was eliminated.

What about your hunting land? Are coyotes killing enough deer to lower your deer population? Could you even be in a dreaded predator-pit scenario?

The key to answering these questions is getting a sense of how many fawns are surviving on your land—your fawn-recruitment rate. If you are worried about coyotes, and you are serious about deer management, there are three things you should consider doing. You should record lactation data, you should conduct trail-camera surveys, and you should keep up with observation data. We’ll go into more detail about all three, but first let’s look at fawn-recruitment rate and why it’s so important.

Fawn recruitment is a management term for the number of fawns per doe that survive to six months of age. Dr. Steve Ditchkoff, an Auburn professor and a top whitetail researcher who heads up Auburn’s Deer Lab, said traditionally in the Southeast, deer managers looked for a recruitment rate of .7. In other words, 70 six-month-old fawns per 100 does was considered to be healthy in the Southeast.

“In a healthy population with deer in good condition and not above carrying capacity, .7 was considered to be a good recruitment rate—.6s were fine, .5s were maybe a cause for concern,” Steve said.

Now, researchers are documenting recruitment rates as low as .25 and even .2 on some tracts of land in Alabama. When we hear that, and we hear coyotes howling at night when we’re in deer camp, the knee-jerk reaction is to get fired up about killing some dang yotes. Count me on that team. But Steve cautioned against knee-jerk reactions.

“Yes, there have been some areas in the Southeast that have documented much lower recruitment rates and have additionally documented high rates of predation on fawns. But where and how prevalent those low rates are is unknown at this time,” Steve said. “I think it can be very educational to understand that just because you see a fawn that died doesn’t mean they are all dying. That happens every day on every piece of property, whether it’s eaten by a coyote or dies of malnutrition, that dead fawn is the norm, not the exception.”

To put this into context, go back to that good, standard recruitment rate of .7 fawns per doe. Now, consider that six months prior when fawns were first born, the average was 1.7 fawns born for every doe.

“If you have .7 fawns per doe, that means 59 percent of your fawns are dying before six months of age. That’s only a 41 percent survival rate,” Steve said. “Most people tend to think fawns just survive unless they’re eaten by something. There are a lot of fawns dying even when they’re in great condition and things are exceptional.”

So, even without coyotes, more than half your fawns die naturally. Now, add coyotes to the mix. If your deer are getting hammered by yotes, and your property is seeing a recruitment rate of only .25, that’s a fawn survival rate of only just about 15 percent. That’s a problem—unless you enjoy seeing very few deer and don’t mind very few buck fawns being added to the population.

Dr. Karl Miller is a professor at the University of Georgia and one of the country’s foremost whitetail experts. Karl was one of the first to begin extensive coyote research about six years ago when he began to suspect coyotes were impacting deer numbers. Karl, also an avid hunter, was hearing from other hunters about seeing fewer fawns, and Karl also began to notice a lot of “dry” does—adult female deer that he or friends killed that didn’t have milk. When he started his research, the general feeling from biologists was that coyotes might kill a fawn every once in a while, but they couldn’t impact populations. His research and studies by others quickly changed that sentiment.

Karl said more than ever it’s important for land managers to get a feel for the fawn-recruitment rate on their land. One way is to keep track of how many does you kill that have milk. This simple effort, recorded on does killed when fawns on your property are 4 to 5 months old, gives you lactation data.

“Record lactation data, and look particularly at how it changes from year to year,” Karl said. “Does that are dried up likely lost their fawns early. If a doe stops lactating, it doesn’t just mean she lost a fawn; it means she lost both fawns if she had two. A 70 percent lactation rate probably means only a ballpark figure of 50 percent fawn survival.”

To measure fawn recruitment or assess predation by coyotes, it has to be done with some type of standardized technique. Keep track of lactation data every season.

Some feel the best standardized technique to measure fawn recruitment is with trail-camera surveys. Dr. Steve Ditchkoff said cameras can be a good tool for measuring fawn recruitment.

“Spread out some baited camera sites. The more sites you can survey that are 100 to 200 acres apart, the better estimate you can get. If it’s one camera per 100 acres, or one camera per 200 acres—it doesn’t have to be exact. Just put the cameras out there. The standard technique we use is to pre-bait for five days with corn and run a camera for seven to 10 days. Simply count how many does and how many fawns you see in the pictures,” Steve said.

There are some problems with using trail cameras to measure fawn recruitment. Fawns come into the baited camera sites more or less frequently based on the time of year. In the early fall, fawns won’t come into baited sites as often as they will when they are older.

“Our data show there is no time of the year when you don’t get biased data from these baited camera surveys,” Steve said. “The best time is probably either the pre-rut or post-rut. Those are the best times, the least biased. But if you’re hunting, you can’t run a baited camera site. You pretty much have to do it post-rut. At that time, your doe numbers are going to be right on, but our studies show your fawn numbers are going to be high, about one-and-a-half to twice as high.”

Instead of trying to adjust your camera survey results for this kind of seasonal bias, the key is to look at data over a period of time, several years at least.

“The take home message is this. You’re not going to get accurate or precise data,” Steve said. “You can’t go out there one time and throw some cameras out and walk away and say, ‘This is what my fawn-recruitment rate is.’ What you can do is get a glimpse of what’s going on. Anytime we do surveys of deer, whether it be with spotlights or cameras, we have to understand it gives us a distorted image of what’s happening. It’s kind of like driving slowly down the road and looking through the bushes at an animal. When you stop at any one spot, you get a glimpse, a distorted image, of what the animal is. When you move the car, you get another distorted image. When you get multiple distorted images, it helps you build a better picture of what’s going on. It’s important to get multiple distorted images—multiple years, multiple cameras, multiple years of observations while hunting, lactation data. The more distorted images you get, it allows you to start to get a better feel for what’s going on.”

Instead of worrying exactly what your fawn-recruitment rate is, think more in terms of getting a sense of what it is, and pay attention to changes and trends over the years.

“You’re never going to get something precise,” Steve said.

Using trail cameras to survey fawn-recruitment rates and other deer-population dynamics is something Lindsay Thomas Jr. knows quite a bit about. Lindsay is Director of Communications for the Quality Deer Management Association (QDMA) and editor of Quality Whitetails magazine, and he also edited a book (see sidebar on this page) called “Deer Cameras, The Science of Scouting.” It is impossible to cover all the important aspects of effectively using trail cameras to survey fawn recruitment in a single article. Lindsay’s book has four chapters on the subject, and if you’re serious about getting a sense of your fawn-recruitment rate, I highly recommend the book.

In addition to camera surveys and lactation data, Lindsay said the easiest-to-gather and potentially most-valuable information is simply recording what you see while sitting in a deer stand.

“The average hunter should be doing observation data. It is the simplest and most accurate of the three. Lactation data is simple as well, but it’s not as effective, not as accurate and has a lot more considerations and a lot more ways it can be misinterpreted,” Lindsay said. “Trail-camera surveys are the best in terms of accuracy if you do it right, and it goes way beyond fawn recruitment. You’ve got deer density, buck-doe ratio, buck age structure, fawn recruitment, predator index. You’ve got a total package of data that really can guide almost every decision in your deer-management program. But it is admittedly difficult, and not everybody can do that. You’re talking about a camera per hundred acres and the cost of running the cameras and sites. Not everyone can afford enough cameras the cost of baiting them and checking them.”

While all three—lactation data, trail-camera surveys and hunter observation data—are important tools to getting a feel for your fawn-recruitment rate, Lindsay recommends at the least that hunters start writing down what we see in the deer woods.

“The average hunter needs to be collecting observation data. Each time in a deer stand, write down how many hours they hunted and the numbers of deer separated by buck, doe, fawn and unidentified,” Lindsay said. “Every deer you see, you put an honest decision on what is was. Was it an adult doe, was it a fawn? Was it a deer I just couldn’t tell what it was, or was it a buck? If fawn recruitment is your interest, write down every time you see a bobcat or coyote, too. You can index that as well. Tally it up.

“Getting the hours you hunted in there is important. The thing to remember about observation data is at the end of the year the total numbers don’t mean anything. You’re not saying I saw 40 fawns last year and 30 this year, so that means I have a problem. You have to index it. For fawn recruitment, the index is fawns per doe. So at the end of the year, you take the total number of fawns, and you divide your does into it and come up with that fawn recruitment ratio, whether it’s .2 fawns per does or one fawn per doe. A lot of factors can affect that total number of deer you saw, right down to your choices of where you hunt this year. But if you index it, that smooths out all those fluctuations and makes it comparable year to year.”

If you want to keep track of predators, your index is the sighting rate per hour. Total up the number of coyotes seen and the number of hours people sat in stands to get the sighting rate.

Record and look at these numbers across years—trends are the key.

“With observation rate, you want to rely less on what I call the snapshot look—what was our fawn-recruitment number this year—and rely more on your trend data—what was it this year compared to last year? This is a way to remove seasonal changes like the acorn crop and stuff like that,” Lindsay said.

To make trend data work and be able to compare it year to year, it’s important to collect it the same every year. If last year no one bowhunted, don’t add bowhunting data the next year. Only compare the same time period. Record the same way every year, so that it compares accurately.

“So that’s it, you track what you see and boil it down at the end of the year to your fawn-recruitment rate, and you track that from year to year,” Lindsay said.

In this new era of coyotes in the Southern woods, monitoring trends in your fawn-recruitment rate is critical if you want to manage your deer.

“We have all this research showing coyotes are hurting fawns in a big way in some areas, but that does not mean it’s happening the same way where you hunt or that there’s anything you need to do about it,” Lindsay said. “Fawn recruitment is where we’re pumping out the deer we’re going to hunt in future years, particularly our bucks. So we want that fawn-recruitment number to be high, and we want to be able to harvest does to manage the density. We don’t want coyotes eating a bunch of fawns. They’re indiscriminate. They’re eating bucks and does. That’s your factory output of bucks for the future.

“If you have a problem with coyotes, you need to find that out and deal with it, but you can’t assume that is happening. That’s where collecting data at your site helps you figure out if you have a problem and if you need to deal with it,” Lindsay said.

Coyotes changed the game. It’s the new face of deer management, and the key to managing in this coyote era is fawn recruitment.

Using Trail-Cameras To Survey Fawn Recruitment Rates

There’s an art and a science to using trail cameras as a tool to survey your fawn-recruitment rate. There’s so much information it’s impossible to include it all in an article. The author highly recommends the book, “Deer Cameras, The Science of Scouting,” published by the Quality Deer Management Association (QDMA) and edited by former Georgia Outdoor News editor Lindsay Thomas Jr.

The book covers all aspects of trail-camera use, and there are four chapters on using trail cameras as a tool to survey your deer herd—from choosing sites, seasonal variations, interpreting and calculating results, pitfalls and the value of trends. To order the book, go to www.qdma.com/shop/category/books or call (800) 209-DEER.

Share.

Leave a Reply

Be the First to Comment!

Notify of
wpDiscuz