Wild Ideas: Deer down, but the sky is not falling

Acorns collected on Aaron Mountain, Castleton.Pam Owen | Rappahannock News
Acorns collected on Aaron Mountain, Castleton.

At the same time I was getting reports this fall of the mysterious disappearance of squirrels, which I wrote about in my last column (Jan. 15), I was also hearing from local residents that they were seeing fewer deer.

At the end of December, Kevin Rose, a wildlife biologist with the Virginia Department of Game and Inland Fisheries (VDGIF), emailed Northern Virginia deer hunters about the status of deer harvests in their areas. In the email, he acknowledges that the department had heard much about deer harvests being down during the recent deer-hunting season from the previous year.

“If you read the Facebook posts of Virginia deer hunting groups, you could be forgiven for thinking the sky is falling,” he added. While the statewide harvest was, by the end of last month, down about 19 percent from where it was in the previous December, “this is not a cause for alarm, especially not in Northern Virginia.”

Reasons given for the decline in the deer harvest last fall, Rose wrote, include the low acorn crop, hemorrhagic disease, coyotes and a reduced population from the “liberal” hunting seasons. While hemorrhagic disease has taken its toll on deer, the most severe declines were in southeastern Virginia, he explains, not here in the Piedmont and Blue Ridge.

The production cycle of acorns over the last few years instead appears to be at the heart of the lower deer harvest last fall. An unusually high number of deer were harvested the fall before (2013) because of the acorn crop failure, Rose writes: “When acorns are scarce, deer have to move more for food, which brings them in contact with hunters more often.”

By Pam OwenPam Owen | Rappahannock News

By contrast the relative boom in the 2014 acorn crop meant deer didn’t have to move far to find food early in the fall but did start to move further out once nearby acorn sources were consumed. In talking about the boom and bust of acorn production (and the corresponding impact on wildlife) with Terry Lasher, the Virginia Department of Forestry senior forester for our area, he suggested that, if acorn production is indeed a major factor in the rate of harvest, that rate should be rising for counties with extended deer-hunting seasons — including Fairfax, Prince William and Loudoun.

Referring to data he compiled from the last six years for the harvests through December of each year, Rose concludes that “the sky is not falling,” that the deer herd in Northern Virginia “is still overabundant and there are plenty of deer out there for the taking!” In Rappahannock, deer sightings this winter seem on the rise from last fall, judging by anecdotal reports. We’ll know more when the VDGIF stats for the extended hunting season come in.

The coyote: villain du jour?

 “When the time comes to single out a culprit for the increasingly thin deer herds on public land, it is often the newcomer of the bunch — the coyote — in the crosshairs of blame,” Susan Trulove writes in an article for the summer 2014 issue of Virginia Tech Research Magazine (research.vt.edu; search on “coyote crossing”).

Healthy adult deer are generally not a target of our local four-legged predators, but fawns, along with weak or dead adults, can be.

Fawns taken by predators in Virginia are likely falling not just to coyotes but also bears and bobcats, according to one longtime wildlife biologist. Larry Sherertz
Fawns taken by predators in Virginia are likely falling not just to coyotes but also bears and bobcats, according to one longtime wildlife biologist.

As part of the Virginia Appalachian Coyote Study, centered in Bath and Rockingham counties, predator expert Marcella Kelly, an associate professor of wildlife in Virginia Tech’s College of Natural Resources and Environment, and her students have been using remotely triggered cameras, scat sampling, noninvasive genetic sampling and radios or GPS/satellite collars to track animals. The ultimate goal of the study is “helping humans and wild predators co-exist,” according to the Tech article.

The coyote study has been going on since 2011, still a relatively short time to have definitive results, but the data being collected is starting to flesh out the relationship of coyotes and other large predators to deer and other native wildlife. With all the high-tech means of collecting data at scientists’ disposal, sometimes, as in this study, it comes down to looking at poop — or scat, as scientists prefer to refer to it.

According to the article, when it comes to deer falling victim to coyotes, “it’s too soon to tell,” says Tech master’s student David Montague, whose research focus is coyote diet (as revealed through scat) and deer populations. The data are showing that coyotes have a “diverse” diet that includes small mammals, such as mice and voles, and a lot of fruit, such as berries and apples, along with insects and deer.

Coyotes are opportunistic hunters and scavengers. “If there are lots of alternative diet options, the coyote may be more likely to pursue them than deer,” Montague is quoted as saying in the article. “But I can’t say where the deer remains found in the scat are coming from. I can’t tell if it is from a coyote kill, road kill or carcass remains dumped by a hunter.”

According to another article about the coyote study, on the Allegheny Mountain Radio website, scientists in the study often thought that scat that contained deer hair was from coyotes but DNA tests revealed that is was from bobcats.

Mike Fies, a wildlife research biologist for the VDGIF for 30 years, suggests that the combined effects of three different large predators — coyotes, bear and bobcats — killing fawns in areas with poor habitat “are enough to knock deer populations back,” according to the Tech article. The impact of coyotes alone on deer numbers statewide is likely “negligible,” he adds.

Whatever the coyote’s role in declining deer populations, the overabundance of deer is having a much bigger negative effect on native ecosystems by consuming many native plants — often stripping forest floors bare. Agriculture also takes a hit, and movement of so many deer into populated areas causes traffic hazards. This plethora of deer is due to human interference in the natural food web, so we might want to rethink who the villain is in this situation.

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Pam Owen
About Pam Owen 275 Articles
Writer, editor, photographer, and passionate nature conservationist living in Rappahannock County, in the Blue Ridge Mountains of Virginia. Two favorite quotes: By E.O. Wilson, who coined the term "biodiversity," "Nature holds the key to our aesthetic, intellectual, cognitive and even spiritual satisfaction”; by Douglas Adams, “I love deadlines. I love the whooshing sound they make as they pass by.”