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QDM and Coyotes

(En anglais seulement)

By: Lindsay Thomas Jr.

He is the trickster in Native American folktales — cunning, mischievous, and, much to the aggravation of those he torments, immortal. He might suffer a temporary defeat, but he will always be with us. Today, deer managers wonder whether this immortal trickster is impacting their efforts to manage deer populations and what, if anything, they can do about it.

For QDM practitioners who worry about coyotes, there is plenty of reassuring news and advice to be found in the results of the most comprehensive, long-term study of carnivores in the United States. Conducted by students and faculty of Mississippi State University (MSU), the project lasted almost 10 years, produced Master’s theses for 10 graduate students and was summarized in the end by doctoral candidate Michael Chamberlain, now a professor at Louisiana State University. At any point in time during the decade of the 1990s, students were tracking 50 to 60 animals through radio-telemetry equipment, including anything with canine teeth from coyotes to bobcats. The research, funded by a number of state and federal wildlife agencies and conservation organizations, produced a wealth of data on many aspects of coyote ecology and behavior, including much on their relationship with whitetails.

Do Coyotes Impact Deer Populations?
Dr. Bruce Leopold is a professor and the head of the Department of Wildlife and Fisheries at Mississippi State, and he supervised the carnivore study. According to Bruce, the overall results of their 1990s research reflected what earlier research had concluded — deer are an important food source for coyotes based on how frequently deer hair is found in coyote scat. However, the manner in which coyotes acquire this food is important.

“Our study showed two main peaks for finding deer hair in coyote scats: during fawning season and during the hunting season,” said Bruce. “The rest of the year there wasn’t much at all. One to five scats out of 50 to 100 that we were collecting per month would contain deer hair.”

The peak during fawning season supported the well-known idea that coyotes are random, opportunistic predators of fawns. Because deer hair became less common in coyote scat for the rest of the year — with the exception of hunting season — researchers concluded that coyotes rarely hunt down and kill healthy deer on their own but feed instead on carrion. Deer killed by cars, disease, hunters, accidents and other causes become food sources for coyotes. As numbers of hunter-killed deer are obviously higher during hunting season, coyotes make use of the resource. Many hunters can tell stories of coyotes arriving at a deer carcass before the hunter — particularly when a hunter leaves a deer overnight and returns to finish trailing in daylight.

But there are also hunters who can tell stories of witnessing coyotes chasing, harassing, and even bringing down live adult deer, particularly in the Northern United States. The December 2004 issue of Quality Whitetails included a series of trail-camera photographs submitted by David Pyle of Missouri. The wintertime photos appear to show two, large coyotes wearing down, killing and eating an adult doe. Whether the doe was injured or sick to start with is uncertain, but on other occasions David has witnessed two, outsized coyotes chasing whitetails.

QDMA member and professional wildlife photographer Bill Marchel of Minnesota has also witnessed coyotes taking down what appeared to be healthy whitetails.

“One evening in February I was photographing near a crossing on the Mississippi River, which was frozen, when I saw what I thought at first was a doe and a fawn running down the far bank,” said Bill. “They were both just loping along like a doe and a fawn would. But it was a doe and a coyote. The doe was running along the edge of the river where the ice is covered with snow, but then for some reason she turned and went out across the river. In the middle of the river there was no snow on the ice, and she went down and went spinning out across the ice. The coyote did the same thing, but it got back up and went over to the doe, which was trying to get back up but couldn’t. The coyote just started pulling mouthfuls of hair from the hindquarters, and he just kept eating until he hit an artery and the doe bled to death. It was a pretty gruesome deal but one of the most dramatic things I’ve seen in the wild.”

The event happened at dusk, and Bill’s camera captured only blurred images in the failing light. Investigating the remains the next morning, Bill found that the doe was a healthy adult that had been carrying twin fawns — strangely, the fetuses had both been removed from the placenta and were lying untouched on the ice, although in the night multiple coyotes had all but devoured the doe. In this case, ice aided the coyote, but Bill maintains that he has found evidence of kills in which ice was not a factor.

“They can and will take healthy adults,” he said. “I’ve tracked chase scenes for a quarter or a half mile or more in snow. They eventually hamstring the deer, and you hit a blood trail that continues for 80 or 100 yards, and then there’s the carcass.”

This behavior, according to Bruce Leopold, is uncommon and in most cases can be attributed to individuals or pairs of coyotes that have learned to use a specific method or habitat feature, such as ice, that facilitates their success. In David Pyles’ photos from Missouri, a frozen pond was located in the background, and tracks indicated that much of the chase had occurred on the pond.

“A coyote is an omnivore,” Bruce said. “When you have an animal like that in a food-rich environment, it’s going to shift food sources. Typically, it’s not going to attack an animal that might injure it, as an adult deer can, when there’s so much else to feed on. However, a coyote is an extremely intelligent animal, and certain individuals can learn how to kill deer and what habitats to find them in.”

Coyotes kill deer. They eat fawns. And some experienced individuals can learn to take down adults. The question is whether this has an appreciable impact on deer populations, and in a broad perspective the answer is no. Though coyotes are a relative newcomer to the eastern United States, in particular the Southeast, they have existed alongside whitetails for millennia in much of the whitetails’ range, and both animals thrive. MSU researchers found that deer were an important food source for coyotes, yet deer populations remained the same in the study area during a decade of research.

Locally, however, there can be situations in which individual coyotes are more than incidental predators of deer. The good news is that Quality Deer Management (QDM) is the most effective prescription for coyote treatment.

QDM Buffers The Impact of Coyotes
MSU’s research helped reveal a number of practices that can limit the impact of coyotes by revealing where and when coyotes are most effective in their predation. “Our results said that the best investment you could make toward limiting the impact of coyotes on deer is not to trap or shoot coyotes but to manipulate the habitat so that deer have many areas for fawning that are scattered across the landscape,” said Bruce.

When deer have many areas to choose from for fawning cover, fawns are scattered rather than concentrated in limited areas of thick cover, reducing the likelihood that individual coyotes will learn prime areas to stumble upon fawns.

“Although coyotes hunt by scent, most fawns give off very little scent for the first few weeks,” said Bruce, “and a coyote has to get within 100 to 200 feet of the fawn to detect it by scenting. So it’s usually a random event when coyotes find fawns. When you have good fawning cover and a lot of it, the coyote has a harder time detecting that prey. Tall grasses interspersed with forbs make good fawning cover. You don’t want a deep thicket, because the doe can’t get in there herself. The fawn can get down out of sight in mixed grasses and forbs, and when it does begin to emit more odor, the grass is minimizing wind movements.”

Bruce cited a study of pronghorn antelope in a population where coyotes were taking extremely high numbers of kids. When cattle grazing was reduced by 25 percent, grasses returned to significant height, and kid survival increased more than 50 percent.
“Good habitat management is providing good food and good reproductive cover, which is also good cover from the elements,” said Bruce. “For example, in the North, don’t get rid of your cedar thickets. That’s good winter cover.”

Deer managers who improve the quality and quantity of bedding, fawning and escape cover for deer are also creating a beneficial situation for rabbits, mice, snakes and other small animals that are staple foods of coyotes. By broadening the range of foods available to coyotes, managers take pressure off deer.

MSU researchers found that fruits of many types were also important foods of coyotes, so much so that coyotes were seen to narrow their focus when certain fruits were available, particularly persimmons but also ground-level fruits like blackberries. Final reports of the study suggested that planting and encouraging fruit-bearing plants would be an effective buffer on deer, rabbits and other prey.

Deer population management can also reduce the impact that coyotes have on fawns. QDM calls for an appropriate harvest of female deer to achieve, among other things, a more balanced ratio of bucks and does. When sex ratios move closer toward a balance, breeding takes place over a narrower window of time because most if not all does will be bred on their first estrous cycle. This also means that fawns will be dropped as a group in the same, short time period. This is a well-known defense mechanism of hoofed mammals that helps them overwhelm predators at birthing time.

“This is known as the satiation principle,” said Bruce. “When your management leads to a tighter fawn drop, the coyote can’t respond effectively. They can’t eat all the fawns before fawning is over. Also, a coyote is a seasonal breeder — it can’t go into estrous and produce pups to take advantage of the food source. Third, it’s not out there hunting for fawns anyway. It’s an omnivore and an opportunistic feeder. Those three factors ensure that you’re going to get a good fawn crop off. But if breeding and thus the fawn drop is scattered over two or three months, that satiation principle doesn’t kick in. As a random predator, the coyote is going to take a higher percentage of those fawns.”

Another piece of advice Bruce offered is to not provide ambush sites for coyotes and other carnivores.

“Sometimes we set the deer up with feeding stations, corn, salt licks, and so forth. That makes the deer predictable, particularly if these sites are limited in number. A doe comes in and brings her fawn and the coyote can take advantage of an easy kill. Make sure you aren’t setting the deer up through your actions.”

Are Coyotes a Greater Threat in Certain Regions?
The impact of coyotes, as demonstrated by what Bill Marchel witnessed on the frozen Mississippi River, is likely more significant for Northern deer populations. Factors like severe winters, deep snow and the tendency of deer to “yard” or concentrate in cover create more opportunities for coyotes to bring down adult deer. In the South, longer growing seasons mean more time for cotton rats, rabbits and other small prey to reproduce and fill coyote stomachs, a buffer that is slimmer in the North.

“Coyotes also have a tighter social unit in northern climates and are more likely to hunt in packs or groups. In the South, coyotes have a more loose social structure,” said Bruce. “But the management implications are universal. Work on good habitat, good forage for deer, good protective cover and good reproductive cover. If you make sure you’ve got good habitat for deer and healthy deer, the deer will deal with the coyote.”

Coyote Control
Any deer hunter who still labors under the illusion that they might rid themselves permanently of coyotes has their head in the sand. Coyotes have adapted to every environment in the world, from deserts to dumpsters, and have successfully resisted millions of dollars worth of eradication efforts, including those led by the United States government. But if you have seen coyotes chasing deer, located the remains of fawns, or lost a harvested deer that the coyotes found first, you may be wondering if population reduction is possible. According to MSUs research, this is a fight you may not want.

“Coyotes are extremely social animals, and they form a rigid social hierarchy,” said Bruce. “If you hit that population, it has the ability to respond very quickly to reduced numbers, and a female may crank out that maximum of 10 to 12 pups in a litter instead of two or three. You can worsen the problem. Now you’ve shifted your population from a few, old animals that are regulating themselves, potentially killing each other to maintain dominance, to a population of young, inexperienced animals in greater numbers who may have a greater impact on your deer population. So, there’s a proper balance between deer and coyotes that regulates itself. You can easily get an overpopulated deer herd, but it’s difficult to get overpopulated coyotes because they don’t mind killing each other.”

In any given area, there are usually dominant individual coyotes, male and female, that defend their territories aggressively. A dominant, territorial male will kill any pups it can find that are not its own offspring. There are also individuals known as “floaters” that don’t have a territory.

“They’ve been kicked out of their parents’ territory, and they’re biding they’re time, waiting for a territory to open up,” said Bruce. “We saw in our studies that open territories were reoccupied within a month or two.”

Random shooting of coyotes by hunters in deer stands has, according to Bruce, no impact on coyote populations because it is just that — random. Coyotes killed this way are usually young floaters rather than older, experienced, dominant coyotes. Hunter sightings of coyotes, bobcats and other small predators are so random, said Bruce, that sightings and harvest by deer hunters make excellent data for tracking trends in predator populations.

“Make coyotes part of your observation data,” said Bruce. “Record over time how many coyotes are observed per hunter, per day. If, over time, say in year three, you are seeing four times as many, then you need to investigate. A carnivore population doesn’t just jump up without a change that has made that possible.”

Habitat management may have increased local rodent populations, increasing coyote health and reproduction. This may sound like a downside to habitat improvement, but it’s not. The coyotes will be there whether you improve the habitat or not, but by increasing cover you give whitetails greater advantage in avoiding predation. You also provide reliable, abundant foods for coyotes other than venison. The coyote population will quickly stabilize, according to Bruce.

Investigate other potential causes of increased coyote populations as well. Bruce said that livestock and poultry operations can sometimes fuel healthy coyote populations through practices like dumping carcasses or remnants in woodlands. Working with your neighbor to prevent these factors can help.

Finally, controlling coyotes through trapping and shooting can be effective in cases where individual coyotes are wise enough to be a problem.

“A wise trapper can surgically remove those animals,” said Bruce. “They know where the good habitat is. Even in low coyote populations, good trappers still have the same success rates. If you see a deer run through and a coyote chasing it, I wouldn’t hesitate to remove that coyote, but don’t rely on that as your regulatory mechanism. A professional trapper can help you in a very short period of time. With the fur trade down, a lot of trappers offer their services for regulating problem carnivores, and you can usually get names of professional trappers through your state or local wildlife biologist.”

Living with Coyotes
Though Native Americans recognized the mischievous and frustrating qualities of the trickster coyote, most tribal traditions also revered his ability to adapt, improvise and ultimately survive. The coyote’s disruptive actions often led unintentionally, in folk wisdom, to positive outcomes for the animal community. Similarly, the coyote should be viewed as part of the complete ecology that Quality Deer Managers work with — he will never be completely eradicated, but in a well-balanced program of quality habitat and healthy deer populations, neither will he be a completely destructive force.