Trapping: Study suggests coyotes not adding to deer decline
By John Hayes
Pittsburgh Post-Gazette
Sunday, June 13, 2010
Since long before Wile E. Coyote met his match with the The Road Runner, the coyote has been misunderstood.Disproportionately blamed for livestock losses and falsely accused of including children in its diet, the coyote was hunted for bounty and slaughtered. In Pennsylvania, some conspiracy theorists still wrongly speculate the coyote was stocked to control the whitetail deer population, while others naively proclaim the resilient canine too smart for hunters and trappers.
Despite liberal hunting and trapping regulations designed to encourage harvest, coyote numbers have exploded in Pennsylvania in recent years, leading some to suggest that coyotes have contributed in a big way to the state's diminished deer herds.But the resurfacing of an eight-year-old fawn-mortality study conducted by Penn State's College of Agricultural Sciences challenges that notion.Duane Diefenbach, adjunct professor of wildlife ecology and leader of the Pennsylvania Cooperative Fish and Wildlife Research Unit, said there's no doubt Eastern coyotes prey on fawns.
But their impact on deer is about the same as in other states, he said, and the proof lies in hunter harvest statistics gathered in the years since the study was completed.The 2002 report found the first-year fawn survival rate was about 25 percent in forests and 52 percent in agricultural landscapes -- about the same as in other states. The fawn component of hunters' antlerless deer harvest was about 40 percent, a figure which has remained generally steady since 2002, the year Pennsylvania Game Commission introduced antler restrictions as part of a plan to reduce the deer population."If coyotes were causing a [fawn mortality] problem that's worse than it was eight years ago, you'd see reductions in fawns at harvest. There would be fewer fawns for hunters to harvest," Diefenbach said. "We haven't seen any change [in the fawn harvest] whatsoever."Diefenbach, who has participated in Game Commission deer studies, said there's no evidence that the increased coyote population has led to increases in fawn mortality.
"There are other factors going on. Not all sources of mortality are necessarily additive," he said. "Maybe the coyotes are getting more [fawns], but the bears don't get as many."That makes sense to Mark Zagger, a successful New York coyote trapper who will host demonstrations at this week's Pennsylvania Trappers Association Convention.
The symbiotic relationship that routinely develops between predator and prey species could explain why coyote numbers are up, the deer population is down, but the hunter fawn harvest has held steady."I'm not familiar with that study, but I agree with the findings based on what I observe in the field," said the veteran trapper, credited with catching more than 100 coyotes a year.Zagger said preliminary findings of an ongoing radio telemetry study at the State University of New York, in which he's involved, show that as the deer population rises the adaptive coyote is taking more road-killed carrion, not necessarily more fresh fawn takeout dinners.
"The coyote gets blamed for everything, " he said. "It's a convenient scapegoat, the ultimate survivor. But people who think coyotes are smarter than people are wrong. The secret to trapping them is that traps and miles catch coyotes.
Don't set six traps, set 60. Don't trap on one farm, trap on 10 farms."
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