Monday, January 07, 2013

Coyotes and Deer?

Virginia
W. Matt Knox, Deer Program supervisor with the State of Virginia, explains that, "In the western part of the state, we very frequently get comments and questions from deer hunters regarding the impact of coyotes on the deer herd. These hunters frequently perceive coyotes as having a negative impact. It should be noted, however, that the deer kill in this part of the state has been at record levels for the past 3 years. However, there has been no decline in deer herds anywhere in the state that can be attributed to coyote predation. I would hypothesize that coyotes feed on deer primarily at three times: fawns during the fawning season, wounded/crippled/unrecovered deer during hunting season and deer in very-poor conditions during late winter/early spring. Luckily there are very few areas or deer in Virginia that meet this criteria." Knox mentions that due to the negative impact of coyotes on agricultural interests, he thinks the state could use fewer coyotes. "Our hunter-survey data clearly demonstrates an increasing coyote population in Virginia."

A coyote trotting through the Eastern hardwoods is becoming a common sight these days, and hunters are beginning to wonder if the predators are having an effect on deer numbers. In some places, whitetail populations have indeed slipped while coyote populations have increased. Hunters in parts of western Virginia and western North Carolina, for example, have seen success rates fall and in some cases, bag limits reduced. Biologists, however, blame the decline in deer numbers directly on the loss of good habitat, not on coyotes. National forests throughout the East are experiencing a decline in suitable habitat as a result of decreased timber harvest, said North Carolina Wildlife Resources biologist Gordon Warburton.
“Cutting timber creates excellent browse and high-quality fawning areas,” he said. “As the forests mature, we have less and less quality habitat because environmentalists have succeeded in stopping timber cutting on public lands.”

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April 28, 2012
Scientific confirmation
Studies show that coyotes eat a significant amount of deer
Science has confirmed what West Virginia's hunters have long suspected: Coyotes eat a lot of deer.
A 20-month study of coyotes' dietary habits found that deer remains were found in nearly 60 percent of coyotes' stomach contents and manure samples.

Geriann Albers, the West Virginia University graduate student who coordinated the research, revealed her findings recently at a meeting of the Northeastern Association of Fish and Wildlife Agencies. She didn't mince words.
"Coyotes in West Virginia are primarily consuming deer," Albers said.

Division of Natural Resources officials commissioned the study to try to determine what impact, if any, coyotes might be having on the state's whitetail herds. The findings appear to show at least some impact.
"Of course, we had no way of telling how much of those stomach contents were the result of predation," Albers explained. "There's probably a good bit of it, but coyotes also scavenge road kills, eat remains of deer gutted during hunting seasons, and scavenge the carcasses of deer that die of winterkill.
"Our findings would suggest that there's a need for further study to see how much predation actually is occurring."

The research that generated Albers' findings wasn't at all glamorous. Instead, it involved hundreds of hours' worth of grisly, smelly CSI-style detective work.

Researchers spent part of that time examining the stomach contents of road-killed coyotes and coyotes killed by hunters and trappers. That, believe it or not, was the most glamorous part.
They spent the rest of the time breaking down coyote manure samples and analyzing the contents.
Deer remains showed up in 59.5 percent of the 969 samples examined. Grass and twigs showed up in 39.7 percent, small mammals such as mice and voles in 19.3 percent, fruits and seeds in 18.4 percent, squirrels and chipmunks in 11.4 percent, birds in 4 percent and rabbits in 4 percent. The percentages add up to more than 100 percent because many samples contained more than one category of food items.

The study found that by volume, deer remains comprised nearly four times as much of coyotes' stomach contents and manure composition as small mammals, the second-ranked category.
Deer accounted for 44 percent of the volume, followed by small mammals at 12.5 percent, squirrels and chipmunks at 8.2 percent, fruits and seeds at 7.1 percent, grass and twigs at 7.1 percent, rabbits at 3.3 percent and livestock at 3.1 percent.

If nothing else, the study showed that coyotes are opportunistic feeders.
"They'll eat anything - and I mean anything," Albers said. "Their diets vary according to what is available."

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