Has an Increase in Coyotes Upset the Ecosystem? If so, How Can You Increase Your Coyote Control?
Two cats and four dogs remain after a coyote killed Jerry Welch’s pet cat, Goldie. A retiree at 67, Jerry has killed an average of seven coyotes per year over the last decade since Goldie’s death. “I plan to rebalance nature with my coyote control tactics,” he says.
The Priceville, AL, man owns Riverside Gun Repair in Decatur. When hunting for coyote control, he uses a Weems wood call that sounds like a dying rabbit. Outfitted with video cameras, electronic signals and wood calls, Welch stalks the predators. “They are much smarter than deer or any other animal—very tricky and far tougher to kill because they have sharper sight, smell, and hearing.”
Are Coyotes Goat Assassins or Scapegoats?
That’s a question researchers at the Alabama Agricultural Experiment Station at Auburn University want to answer. After all, the coyote population in Alabama has mushroomed. As their numbers have grown, so has their infamy as “top dog.”
Roland Kays, a mammalogist at the North Carolina Museum of Natural Sciences in Raleigh, found that northeastern coyotes carried genes from Great Lakes wolves, showing that the two species interbred. These beefy coyotes can take down larger prey; they killed a 19-year-old female hiker in Nova Scotia in 2009. Oddly enough, it’s the smaller coyotes in the Southeastern US that are having a real impact on deer. The region’s deer are usually smaller than those in the northeast.
Lack of coyote control is the blame when numerous fruit and vegetable crops are damaged and livestock—newborn calves, sheep, and goats—are killed. However, free-ranging dogs and unattended pets will often kill livestock. Also, raccoons can cause coyote-like damage to fruit and vegetable crops. Yet, coyotes do eat everything from fruits to small rodents and deer. They will also scavenge carcasses of dead animals.
“There are reports of people killing coyotes even in the 1920s, so they’ve been here a while,” says Jim Armstrong, Auburn University professor of forestry and wildlife sciences. Reportedly first introduced in Alabama by fox hunters, the coyote population has been growing. They are now in 67 counties.
From 1986 to 1987, there were 5,264 reported killings of coyotes in Alabama. During 1987 to 1988 there were 13,137 reported kills. An adult coyote may give birth to four to eight pups and vary in size from 20 to 50 pounds. However, a 104-pound coyote was killed in Carroll County, Missouri, in 2011.
Do Coyotes Seriously Threaten Deer Populations?
According to Keith Causey, also an Auburn wildlife researcher, coyotes will feed on deer during fawning season, when newborn fawns are easy prey. Jerry Welch agrees. “Coyotes kill 30 to 50 percent of whitetail deer fawns,” he says.
At Auburn, after Dr. Stephen Ditchkoff examined mortality factors of fawns in one urban Alabama study site, it was found that fawns suffered a 67 percent mortality rate with lack of coyote control being the leading cause. In one study fawns increased from 25 percent to 75 percent the local coyote population’s diet.
“‘Two coyotes, in fact, can kill a mature deer,’ Welch asserts.”
John Kilgo, a wildlife biologist with the US Forest Service, states that lack of coyote control caused more than one-third of the fawn deaths in one South Carolina area. But other evidence suggests that the true number might be closer to 80 percent.
“Two coyotes, in fact, can kill a mature deer,” Welch asserts. “One grabs the deer’s throat and the other latches onto the sternum to quickly peel down so that the intestines fall out—all done in about one minute.”
More than a dozen residents near Decatur have reported their pets missing. Coyotes stand at the edge of yards, intently watching dogs and cats. “The coyote population keeps increasing,” Armstrong says. “Instead of reports about coyotes disturbing the agriculture, I get reports from people worried about their pets and children.”
He has studied the predators at Auburn for 19 years. “If they associate humans with food and become habituated, then they are more dangerous.”
“One problem is when people trap raccoons or other animals,” Welch adds. “They turn them loose at some animal refuge where local coyotes have a feast. I found where a coyote pulled the hindquarters off a house cat and left the remainder.”
Is Trapping Coyotes Effective?
Stanley Gehrt, who led the EcoSummit 2012 research on coyotes, told Discovery News that “We’re finding that these animals are much more flexible than we gave them credit for.”
Coyotes are opportunistic and will do whatever it takes to stay alive, often taking the easiest meal they can get. Adults form pair bonds and stake out territories that range from three to 30 square miles.
Trapping coyotes for coyote control is a more intensive option but it must be correctly done to be effective. Trapping conducted immediately prior to and during the fawning season, or other coyotes will quickly repopulate the area. Shooting coyotes at every opportunity may worsen the problem by temporarily reducing competition for resources, which can increase coyote pup survival.
Wildlife biologist Stewart Abrams contends that large-scale coyote removal is too expensive and time-consuming to be feasible. “Removal techniques such as trapping and shooting have little effect on their populations because other coyotes will reoccupy their territory,” he says. “Coyotes have the ability to increase populations by reproducing more often and increasing the total number of pups per litter.”
Can Coyotes Spread Lyme Disease?
A deer carries hundreds of ticks on its body, but mice and other small mammals are major carriers of Lyme disease. In fact, in a new study published in the Proceedings of the National Academy of Sciences, researchers found a significant correlation between high numbers of coyotes and high numbers of Lyme disease cases.
Coyotes interfere with the role served by foxes to suppress rodent hosts of Lyme disease because they are not efficient predators,. Using harvest records among hunters from 1982 to the present, researchers discovered the incident of Lyme disease mirrored the rise of the coyote population and the decline of foxes.
Ecologist Taal Levi, now at the Cary Institute of Ecosystem Studies in Millbrook, N.Y., says that records from the past three decades show a link between rising numbers of Lyme cases (30,000 in 2010) not with booming deer populations but with coyotes. As coyotes have trotted into suburbia, red foxes have retreated and allowed rodents to survive. Where foxes are thriving, the risk of disease drops.
That scenario—coyotes in, foxes out, small rodent numbers up—is, therefore, fueling the spread of Lyme disease. Foxes won’t make dens when coyotes move into a neighborhood. Says Lyme disease ecologist Richard Ostfeld, “Reducing the deer herd by even as much as 60 or 70 percent likely won’t do squat to the tick population.”
Who Says Coyotes Are Eco-friendly?
Some believe that coyotes fill a critical niche in the ecosystem vacated by the endangered red wolf and extinct eastern cougar. For areas overrun with deer, such as Oak Mountain State Park near Birmingham, a pack of coyotes may be a welcome sight to these urban dwellers.
But why stop with deer? Feral-cat problems plague many suburbs. It is well-documented that domestic cats are enemies of songbirds, killing as many as a half-billion each year. Coyotes happen to have a taste for cats. And in a study published last September in Zoonoses and Public Health, cats comprise 62 percent of all rabies cases.
How Adaptable Are Coyotes?
Coyotes are going through a whole new set of changes as they adapt to the modern American landscape. Genetic studies show that some wily coyotes are even interbreeding with dogs, which could lead to a different sort of hybrid animal.
Coyotes have moved into Washington DC, appearing in Rock Creek Park, just a few miles from the White House. Christine Bozarth, a conservation geneticist, has shown that some of them descend from the larger northeastern strain and carry wolf DNA. “They raise their pups in drainage ditches and old pipes,” she says.
Shape-shifting coyotes are taking advantage of a landscape transformed by people. Long story short: Coyotes are here to stay.