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The Effect of Coyotes on Deer Populations

The Effect of Coyotes on Deer Populations

The effect of coyotes on deer populations is an area of great interest and concern to land and wildlife researchers and managers.  Due to the declining fur market over the past several decades, the coyotes’ range has expanded dramatically.  With litters of up to 19 pups, coyotes’ numbers increase every year.  Tagged coyotes have traveled over 400 miles, and they now inhabit the lower 48 states and Alaska.  

During the booming fur industry, the southeast had no coyotes and a high deer density.  Now deer are scarce in in some high-density locations previously having 50+ deer per square mile.  The U.S. Government has to kill over 90,000 coyotes yearly because of stock predation.

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Studies: Effect of Coyotes on Whitetail Deer Populations

Studies have confirmed that coyotes affect whitetail deer populations.  The researchers of a northern Alabama study included Dr. Karl Miller[1] of the University of Georgia, Cory Van-Gilder[2], graduate of the University of Georgia, and Dr. Grant Woods[3], graduate of Missouri State University, University of Georgia, and Clemson University.  The study focused on 2,000 acres where 22 coyotes and 10 bobcats were removed during fawning season.  The result was a doubled fawn population.

Later, Miller went on to conduct a second study in Southwest Georgia on 2 sections of land.  One section of 11,000 acres, 23 coyotes and 3 bobcats were trapped and on another 7,000 acres no trapping was done.  The results were staggering.  In the trapped area, 2 out of every 3 does had fawns. In contrast, in the un-trapped area only 1 out of 28 does had fawns.

Dr. John C. Kilgo[4] at the U.S. Forest Service at the Savannah River Site in South Carolina conducted one of the largest studies concerning the affects of coyotes on whitetail deer.  Sixty fawns were collared and observed.  Within the first 6 weeks, 73% (44) of the fawns died.  Approximately 80% (35) were killed by coyotes, 13% (6) were killed by bobcat, and 7% (3) by unknown causes. 

Dr. Kilgo’s Research on Deer without Collars

Dr. John C. Kilgo conducted another study on the adjoining land with deer having no collars. The researchers used only trail cameras to prove that the collars didn’t slow the fawns down.  The mortality rate was the same. 

Dr. Kilgo’s most recent studies disprove the theory that fawning cover will reduce the predation of fawns, finding the same results on land with less fawning cover. 

Dr. Kilgo and Christopher Shaw of the U.S. Forestry Service tested the theory of “predator swamping” where the buck-to-doe ratio was balanced, wherefore all the fawns would drop at the same time.  They conducted a test on 2 tracts of land, on the first tract the deer had a high density and on the second tract a low deer density.  Even though the land had roughly the same amount of coyotes, the rate of predation was roughly the same.

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Additional Studies of Effects of Coyotes on Deer Populations

In year 2005, Dr. Stephen Ditchkoff [5] of Auburn University and his students began collaring 50 fawns a year.  When starting, they scarcely had a fawn killed by coyotes, but in 2008 34% were lost and in 2009 over half were lost. 

Mark Buxton[6], a wildlife manager with Southeastern Wildlife Habitat Services in Thomaston Alabama, says at the QDMA’s annual convention in Louisville Kentucky “…food plots, timber stand improvements, and restoring native vegetation… can maximize their (the deer) potential.  The coyote is the next big part of that equation.”  Buxton says “if coyotes are not a problem on your hunting property they will be in a few years.” 

Coyotes Target Fawns

It has been said that fawns were at the wrong place at the wrong time.  Buxton believes this is not the case.  He trapped predators in 2009 during 3 months of spring and caught 20 coyotes and 15 bobcats from 1500 acres, beginning about a month before fawning begins.  After 1 year, Buxton had caught 49 coyotes and continued into the 2010 fawning season trapping 14 more.  In total, 54% of the coyotes trapped were caught during fawning season (34 of 63). 

“That tells me when coyotes are targeting fawns,” Buxton states, “when fawns hit the ground its game on for coyotes”.  Ditchkoff agrees, saying, “coyotes might have learned to identify doe behaviors that indicate fawns are nearby. That’s not unheard of.  In Alaska, they’ve documented that when a cow moose acts in a way that indicates a calf is nearby, brown bears start a systematic search to find the calf. They just hammer moose calves.”

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A Sharp Decline in Deer Population

During the late 1980’s coyotes advanced into South Carolina and by year 2006 the deer population declined by 36%.  Is this merely by chance?  An in-depth study on Michigan’s Upper Peninsula indicated coyotes kill more grown deer and fawns than wolves, bears, or bobcat.  For 3 consecutive years coyotes caught and killed more adult deer leaving their competition in the dust. Coyotes killed 7 deer, whereas wolves killed 3. Bears and bobcat trailed behind with 1 each.  Coyotes were also the apex killing predator fawns with 22.  Bobcats killed 12 and bears and wolves tied at 4.

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In yet another study, Sarah Saalfeld[7], a student of Auburn University, under the direction of Dr. Stephen Dithckoff, found coyotes impacted deer in an urban environment the same as in the wild, contradictory to the expectation that cars would be the highest cause of mortality.  Coyotes killed 67% of the fawns in an urban environment just as in rural environments.

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It appears coyotes negatively influence deer populations.  The elimination of coyotes have been known to double the survival of fawns.  The removal of predators, especially coyotes can significantly increase the deer population. Do your part to put these fawn slayers in check by trapping and hunting and to bring back a thriving deer herd, but be sure to check your states laws before you go out!

 

Hampton Harris

 

[1]Miller, Karl The Coyote Factor – Taking a Bite Out of Deer http://www.aonmag.com/article.php?id=2077&cid=189

[2] Van-Gilder, Cory The Coyote Factor – Taking a Bite Out of Deer http://www.aonmag.com/article.php?id=2077&cid=189

[3] Woods, Grant The Coyote Factor – Taking a Bite Out of Deer http://www.aonmag.com/article.php?id=2077&cid=189

[4] Kilgo, John C. The Coyote Factor – Taking a Bite Out of Deer http://www.aonmag.com/article.php?id=2077&cid=189

[5] Ditchkoff, StephenHow Coyotes Affect Deer Herds http://www.americanhunter.org/articles/how-coyotes-affect-deer-herds/

[6] Buxton, Mark How Coyotes Affect Deer Herds http://www.americanhunter.org/articles/how-coyotes-affect-deer-herds/

[7] Saafeld, Sarah The Coyote Factor – Taking a Bite Out of Deer http://www.aonmag.com/article.php?id=2077&cid=189

Mulligan, Don Study Shows Coyotes Impacting Deer Populations http://www.kpcnews.net/outdoors/index.php?option=com_content&view=article&id=665:study-shows.

 

 

18 responses to “The Effect of Coyotes on Deer Populations”

  1. […] hens to every one jake.  We believe that the reason for the enormous hen population is due to the predator killing we did the previous year on our land.  Keeping the predator population down is of utmost […]

    • J.J. says:

      Didn’t get my turkey this spring turkey season, but I did take out a pregnant female coyote on the last day of the season.

  2. Qed Suvwi says:

    Things from the study omitted here:

    Trapping coyotes is another more intensive option but can be expensive and must be done correctly to be effective. If you trap, it must be conducted immediately prior to and during the fawning season, or other coyotes will quickly repopulate the area. Opportunistic harvest of coyotes (i.e. shooting every one you see while deer hunting) will typically have little or no effect. In some cases it may even worsen the problem by temporarily reducing competition for resources, which can increase coyote pup survival.

    Also

    Until we have more southeastern coyote/deer research under our belt, those are the management options we have to work with. Regardless of the methods you choose, I highly recommend consulting a wildlife biologist to help you efficiently meet your management goals. I’ve worked with numerous hunt clubs that believed that coyotes were decimating the local deer population only to find out that their harvest rates far exceeded what the herd could handle. Deer hunting and management are evolving rapidly, and relentless research is the only way to keep up.

  3. […] native plant and tree in the Southeast at 14. My other son wrote my highest read blog entry about Trapping which has been used by many blogs and […]

  4. Charles May says:

    When I was growing up it wasn’t anything to see 10 to 20 DEER around my Grandpa’s land then I kill my FRIST Coyote in 1989 I didn’t even know they were around middle GEORGIA then people kept saying the Game Wardens were bringing them in Lord I didn’t even know the y that they were moving in to Ga. Now back here in the Country where I live I can hear droves of them howling at night I TRULY GOING TO START BUYING UP TRAPS TO TRY TO GET THEM THING UNDER CONTROL CAUSE WE DEPEND ON THE DEER TO HELP US SUPPLEMENT OUR FOOD SORCE HERE ! GODBLESS YOU ALL FOR YOUR STUDY PLEASE GET THIS INFORMATION OUT TO LET EVERYONE KNOW JUST HOW IMPORTANT IT IS TO GET THE COYOTE UNDER CONTROL

    • Stacy Harris says:

      Thanks for your comment. Isn’t that the truth. We do need deer to supplement our food. Of course I am prejudice. I think it is the best food in the world!

    • Sal Sorace says:

      I think the game commission should respond to all of us with what they intend to do,to help us deal with this problem.

  5. Brian Miller says:

    First of all, I am a deer hunter and enjoy seeing coyotes. They are an awesome animal to say the least. As I see it, there is no crime in hunger. Just look at coyote predation like a wildlife tax. But most of you pigs can’t see past your #$#%#$ to give a damn about anything but your own selfish, pathetic interests. I could go on and on….The same mentality that basically destroyed this country’s wildlife heritage.

    • Cameron Moore says:

      you don’t no what you are talking about brian miller you just want a reason to b#$$# about every thing it is a problem the coyotes in America so get it together it is just there opinion.

    • Stevie says:

      Dear Brian,

      You started off perfectly balanced. However, you quickly slid into nonsensical babbling. I love coyotes because they balance the deer heard. I have had trail cameras out for 10 years in two different states. (Oklahoma and Missouri)

      If the coyotes kill and eat that big buck on my trail camera I have to get over it. I can go buy a chicken and eat it, a coyote must hunt for a living. Seemingly sadly its the fawns who are eaten, we all know it’s just nature. But, we all like fast food once in a while don’t we? If the deer numbers are thin the coyote numbers will balance naturally.

      One more quick point about field dressing deer. Why do we leave that much free food in the woods. I have put game cameras on my gut piles. The coyotes are shy for a while, but soon take advantage of the free food. They don’t have to expend any calories to catch a 5 pound energy packed liver. All of nature is basically a math problem. They receive free energy and as you know wild animals waste next to nothing. We actually help coyotes through a cold winter with a belly full of organ meat.

      My recommendation: Don’t leave anything in the woods but a blood trail. Pack all of the animal out. I know it’s a pain in the rear, but, it does not give the coyotes a free meal to boost their energy in a time that they should be balancing their numbers. (just a thought?) I know some of you reading this also practice this same tactic.

      I love it when the coyotes eat the neighborhood cats. Nothing against cats it’s that they insist on urinating on everything I own. I know, I know it’s just nature. But, domesticated animals are not part of nature. They are man made. They don’t belong.

    • Galen says:

      Thanks for being a voice of reason. I can’t believe the number of know-nothings attempting to justify the creation of a serious wildlife imbalance. Hasn’t history taught them anything? Do they begrudge every predator species a meal? Sure is some old-times attitudes here.

  6. Steve says:

    I’m not an expert or anything, but since whitetails co-evolved with red wolves, surely they’ll be able to handle this influx of a similar predator. Unfortunately this probably means people who really need venison are going to have a hard time in the near future. From what I’ve read, killing coyotes is more or less a waste of time (if you’re trying to control their population, obviously some people probably like hunting them for sport or other perfectly valid reasons) since there’s an insane abundance of food (which is a good thing) and they can have so many babies in a good year. We have open seasons on coyotes and wild hogs in NC and both populations continue to rise.

  7. Chowey says:

    Coyotes are a huge problem in Montana. The deer population is going done and i have barely seen any fawns this year. Coyotes need to be stopped; hunters need to pick up there game and tree hugger need to back off.

  8. Edward Heisel says:

    Have we learned nothing in the past 150 years? Nature requires predators to create some sort of balance. Killing coyotes is senseless slaughter that does harm to the environment. Plus, they’re really cool animals to watch and listen to.

  9. Wow, it’s impressive to know that the absence of coyotes can potentially double the population of deer. I might try to get a coyote control service for my rural property soon because I’d like to start raising some deer and let them roam around the surrounding woods. With predators around, that would be quite impossible to do.

  10. Rattlerjake says:

    Edward Heisel – It is untrue that nature requires predators to create balance! Nature creates imbalances all the time. Killing coyotes is not senseless slaughter that does harm to the environment because the way nature works is that certain predators, in areas where prey species are plentiful, often increase their population over the carrying capacity, and they over predate the prey species often to the point of extermination. When this happens, either the predators start dying from starvation or they begin predation on other non-species, including those that do not have sustainable populations which then causes their extermination, then the predators die off from starvation. Those prey species often take many years to repopulate the area and the other species that were eliminated may or may not – these are called cycles, and happen over several year span. (Example: In years that the snowshoe hare/rabbit are plentiful, usually because the lynx/bobcat populations have declined, the lynx/bobcat population increases due to the increase in available prey species and more kittens survive. But as soon as the “cat” population is high enough to significantly reduce the rabbits, the cats starve out.)

    MAN is a predator, a predator that has the ability to maintain animal populations a optimum carrying capacity by regulating the numbers of predators and prey species, and preventing the decimation of both. Also when man does this, these animals are not wasted through starvation, they are harvested for food and/or their pelts. The only problem with this is the fools that insist on protecting every animal on earth, which then leads to the imbalances as mentioned before.

    In North America there was once a population of bison that numbered in the millions. That population allowed for huge numbers of predators. But as is seen in other continent’s herd animals, when the predation becomes too high, those herds migrate out of the area and the predators starve, or if the predator numbers were not high enough there would be huge die-offs of the bison because they over grazed the land. This we never experienced because the American aboriginal (from Asia) hunted the migrating herds, just as the other predators do.

    Man has been an integral part of nature’s “balance” since the beginning of time!

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