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."
For example, the study found that deer remains were only half as abundant in coyotes from West Virginia's southern coalfields, where deer populations aren't nearly as dense as in the rest of the state. Albers said that in the coalfields, coyotes ate deer far less often and ate plants and squirrels far more often.Hunters have long accused coyotes of killing large numbers of newly born fawns, but the study's findings didn't bear that out. In fact, the data revealed that coyotes feed most heavily on deer between January and April."Studies in other states have shown that during times when snow is deep, coyotes have an easier time preying on deer," Albers said. "Winter is also a time when deer die of winterkill, and they travel on roads to avoid deep snow and get hit by cars. Scavenging accounts for a good percentage of winter deer consumption stems from scavenging, but there's probably a lot of predation too."During the January-April time period, deer showed up in more than 70 percent of coyotes' stomach contents and stool samples. Between May and August, which includes the fawn birthing period of May and June, only 55 percent of the samples contained deer remains."One of our more interesting findings was that the percentage dropped to just 38 percent between September and December," Albers said. "At first glance that seemed odd, because that period includes the hunting seasons. Between wounding loss and piles of offal left from field dressing, coyotes have a lot of opportunities to eat deer."We think the drop-off occurs because coyotes can take advantage of easier food sources during that time period. During our survey period, there were oodles of squirrels, and lots of fruits and nuts. It's easier for a coyote to eat a persimmon or kill a squirrel than it is to kill a deer or find a gut pile left by a hunter."
Another finding that defied conventional wisdom was the study's discovery that turkey remains and turkey eggshells didn't often show up in the stomach contents or scat samples.Hunters have long believed that coyotes prey heavily on nesting hen turkeys and their eggs, but Albers said the data show just the opposite."Of the 4 percent of samples that contained bird remains, only half of those were from [ground-nesting] birds such as turkeys and grouse," she said. "We did find some shell fragments, but those were from turtle eggs. We found no evidence of bird shell fragments."Still, Albers has no doubt that a coyote would eat those things if it had the opportunity."They will eat just anything. We saw remains of skunks and opossums - things you wouldn't think they would eat," she said.One coyote took its eat-anything reputation seriously."It must have been a Dumpster diver," Albers said with a grin. "In its stomach we found the remnants of a Dairy Queen napkin, a Subway sandwich wrapper, a Taco Bell sauce packet and a commercial crab leg."Reach John McCoy at firstname.lastname@example.org