Tag Archives: aaron wirsing

North-central Washington Mule Deer ‘Really Changing Their Home Ranges’ In Response To Wolves: UW Study

A University of Washington press release is fleshing out something I reported before last deer season:

Muleys and whitetails are beginning to change their behavior as wolf numbers increase in North-central Washington, and hunters might want to start looking in rougher country for the big-eared bounders.

A MULE DEER DOE AND FAWN CAPTURED ON A TRAIL CAM DURING A UNIVERSITY OF WASHINGTON WOLF-DEER STUDY. (UW)

“Overall, the researchers found that mule deer in gray wolf areas changed their behavior to avoid wolves altogether — mainly by moving to higher, steeper elevations, away from roads and toward brushy, rocky terrain,” states the news release that came out yesterday.

“Alternately, white-tailed deer that favor sprinting and early detection as ways to escape from predators were more likely to stick to their normal behavior in wolf areas, sprinting across open, gently rolling terrain with good visibility — including along roads,” it continues.

TWO WOLVES ROAM ACROSS A SNOWY EASTERN WASHINGTON LANDSCAPE. (UW)

That conclusion from the press release is based on field research involving collared deer and wolves and trail cams from 2013 through 2016 in areas of Okanogan and Ferry Counties occupied and unoccupied by packs.

“Mule deer faced with the threat of wolves are really changing their home ranges, on a large scale,” said UW School of Environmental and Forest Sciences associate professor Aaron Wirsing.

He is one of six UW, Oregon State University and other coauthors of an article recently published in the journal Oecologia recently.

He said that the species is moving uphill into less smooth territory “where wolves are less likely to hunt successfully.”

While the UW press release does note that that shift “could affect hunting opportunities” — “Indeed, some hunters in eastern Washington have already reported seeing mule deer higher on ridges where they are less accessible than in past years” — what it doesn’t mention is that that move just puts muleys closer to the jaws of another predator better adopted to stalking rough country.

Mountain lions.

A SCREEN GRAB FROM A VIDEO CAMERA SLUNG AROUND THE NECK OF A WHITETAIL DOE FOR THE UNIVERSITY OF WASHINGTON’S DEER-WOLF STUDY SHOWS A MOUNTAIN LION ATTACK. THE CAMERA WAS LATER RECOVERED AND ITS VIDEO POSTED TO NRA PUBS’ YOUTUBE CHANNEL.

One of the coauthors, Justin Dellinger, pointed that out when I spoke to him in the lead-up to 2018’s rifle buck hunt.

While the number of deer killed by wolves in the study was considerably fewer than how many cougars took –2 vs. 12 — he was quick to note that the data set is short, and it’s specific to North-central Washington and the early stages of wolf colonization.

Dellinger stated that the study occurred during relatively easy winters and theorized that in a severe one, mule deer driven down into open lowland winter range by snow could be preyed upon more heavily by wolves.

But there can be no doubt that even as deer adapt to the return of the long-legged lopers, they are still ending up on the menu.

Not far to the east of the study area, in similar though more densely forested country with fewer muleys and more whitetails, another UW researcher and his scat-sniffing dogs found that deer are the primary food source for wolves.

LAST YEAR A TRAIL CAMERA CAPTURED WHAT’S BELIEVED TO BE A SMACKOUT PACK YEARLING PACKING HINDQUARTERS OF A WHITETAIL FAWN BACK TO THE DEN IN NORTHEAST WASHINGTON. (JEFF FLOOD)

Earlier this winter, Dr. Samuel Wasser told Washington lawmakers, who funded his work, that they collected 8,456 piles of poo in northern Stevens and Pend Oreille County between April 2015 and June 2017, ran 6,095 through a lab and found that 826 had been left by 114 individual wolves.

As for what those packs were digesting, deer represented the largest portion of their diet, though moose weren’t far behind.

A PRESENTATION BY A UNIVERSITY OF WASHINGTON PROFESSOR BEFORE THE STATE LEGISLATURE SHOWS WHAT LAB ANALYSIS FOUND TO BE KEY PARTS OF THE DIET OF WOLVES IN NORTHEAST WASHINGTON. (DR. SAMUEL WASSER)

Deer also made up the plurality of cougar and coyote diets.

According to the UW press release, wolves will chase deer  “sometimes upwards of 6 miles.”

It postulates that whitetail hunting “likely won’t change to the same degree with the presence of wolves.”

It also says that the return of wolves to deer country “could affect other parts of the ecosystem,” likely meaning vegetation cover, “and perhaps reduce the number of deer-vehicle collisions.”

A heat map detailing where roadkill salvagers have picked up the most deer on state routes since July 2016 does show a number on Highways 20 and 21 in the area near where the wolf-deer study took place, but much higher concentrations in more populated areas where wolves are somewhat less likely to occur.

A MAP PREPARED FOR THE WASHINGTON FISH AND WILDLIFE COMMISSION EARLIER THIS WINTER SHOWS ROADKILL SALVAGE HOT SPOTS FOR BLACKTAIL, WHITETAIL AND MULE DEER ACROSS THE STATE. (WDFW)

The UW wolf-deer study was funded by the university, National Science Foundation, WDFW, Safari Club International Foundation and Conservation Northwest.

The Colville Tribes recently changed its wolf season for tribal members in areas that were part of the study — the reservation and the “North Half” — to year-round without a quota.

WDFW and UW researchers are also in year three of a five-year predator-prey study across the northern tier of Eastern Washington that should also bring new information about how wolves, deer, moose, elk, cougars, coyotes and other critters in the area’s wildlife guild are adapting to the changing dynamics.