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Deer herds devouring forest seedlings, urban hostas

By Ron Way | Monday, Feb.

The whitetail deer, an outdoors icon so revered that it’s featured on Minnesota’s conservation license plate, has become a troublesome pest in many parts of the state. Deer are devouring seedlings so fast that regeneration of desired hardwoods has stopped.

“There is no new growth of red oak in far Southeastern Minnesota or in the ‘Big Woods’ area in the west Twin Cities metro,” said University of Minnesota forest ecologist Lee Frelich, adding that regeneration of red oak, white pine, white cedar, hemlock and yellow birch is stunted or worse across North Central Minnesota and along the North Shore. A wide variety of forest plants — to say nothing of urban-area ornamental shrubs and hostas — are being gobbled up.

Deer populations have exploded in the past 30 years. Mild winters, coupled with fundamental change in the way land is used and forests are cut, have created ideal conditions for herd growth that by historical standards is staggering.

A ‘too-successful’ effort
“Deer have been managed to increase the herd for hunting, and the effort has been too successful,” said Matt Norton, a wildlife specialist with the Minnesota Center for Environmental Advocacy. Norton, himself a deer hunter, is among a growing number calling for more aggressive measures to reduce deer numbers.  

There were maybe 50,000 deer in the state in the early 1900s, and through the 1960s the ungulate was rare enough that seeing one caused the family car to stop for an extended look-see. Minnesota’s whitetail was so depressed by a series of harsh winters that in 1971 the hunt was canceled.

State hunters bagged 255,000 deer in 2007 — five times the total herd estimate of a century ago. And yet, there are still more than a million of the critters living — and eating — through yet another mild winter. As happens with favorable conditions, many pregnant does will give multiple births and by summer whitetail numbers are expected to be right back to where they were before last fall’s kill, or higher.

“Deer are opportunists that thrive where there’s food and security,” Frelich said. He said there is “broad scientific consensus” that too many deer are causing “significant” environmental damage across Midwest and Eastern U.S. forests.

Cars hit some 20,000 in 2007
In urban areas where there is no public hunting, cities conduct special hunts to help keep deer out of gardens and off roadways, where last year upwards of 20,000 were hit by cars. The favored means of herd reduction are sharpshooters with silencers or, as in Ramsey County, bow hunters (experts say that nonlethal methods are costly and don’t work).

In out-state areas, the Department of Natural Resources (DNR) is working to get hunters to where deer density is highest. “We have population-density targets in every hunting area,” said Lou Cornicelli, DNR’s director of big-game management.

The unavoidable result is a crazy-quilt of hunting bag limits in Minnesota’s 130 permit areas. Hunters can take a single deer in the Arrowhead and Southwestern Minnesota, but throughout North Central Minnesota they can take anywhere from two to five animals, mostly does. Taking out reproductive does rather than bucks is the best way to reduce the herd through hunting, but it’s not always desired by hunters, whose every media image of a successful hunt is a stately buck with a spreading antler rack. 

Private owners create refuges

Rick Horton, DNR’s forest game biologist in Grand Rapids, Minn., cited two other problems that game managers would like to see changed: hunting groups in high-density deer areas that insist on a bucks-only rule (it’s the opposite of what’s needed to bring numbers down) and private landowners who don’t allow hunting. Broad acreages of the forest have been sold off by timber companies, and private buyers restrict hunting and give deer a virtual safe refuge from hunting, which is essentially the only way that DNR controls deer numbers.

Other than the Twin Cities metro, the epicenter of high-density deer is 15-20 miles on either side of U.S. Highway 10 between Wadena and Detroit Lakes, with another pocket in far Southeastern Minnesota. DNR models show there are more than 40 deer per square mile in the two out-state areas, while in the Twin Cities the numbers are sometimes twice that.



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The ideal deer density is 8 to 10 animals per square mile, Frelich said, but Cornicelli says that up to 25 animals is OK for many areas. 

Mark Johnson of the Minnesota Deer Hunters’ Association in Grand Rapids says woodland habitat can “carry more deer.” Johnson said there are nuisance whitetails in isolated areas, and that too often hunters cannot get to woods where deer concentrations are high.  

“I’ve seen plots where foresters set out fertilized seedlings that are like candy to deer, and it’s little wonder that seedlings disappear,” Johnson said. Overall, he added, properly controlled hunts can continue to provide a quality hunting experience and keep the herd size in balance.

Too many people feeding deer
Outdoor writer Shawn Perich of Hovland, Minn., agrees that deer are not necessarily overabundant. He said too many people feed deer and bring them into unnatural situations that eventually cause conflict. The real problem, Perich added, is “people building trophy homes” along the North Shore and in the forest.

Which goes to a point on which everyone seems to agree: Minnesota’s forestlands are being fragmented with roads, cabins, driveways and numerous small patches of clear-cuts. It creates “edge” where open areas meet the woods, and it’s ideal deer habitat — especially if, as in urban areas, there’s abundant food and no hunting pressure. More edge is continually created, resulting in more deer. It started in the late 1800s and early 1900s with farms being cut into forests, along with wholesale logging of Minnesota’s native pines, and it’s continuing today as more and more forest is carved up for cabins and homes.

A related problem is a radical change that forest practices brought on in the 1970s when University of Minnesota researchers perfected the processing of fast-growth aspen into pulp, transforming a plentiful “junk” tree into a prized commercial species that’s now intensively cut. It created more habitat — and more deer to eat new plantings of the very tree coveted by pulp-makers. 

Another irony is that 1970s Earth Day environmentalists railed against clear-cutting broad swaths of the woodland. Foresters obliged with much smaller 20- to 40-acre clear-cuts, effectively creating much more edge and, of course, many more deer.

Wetlands left intact
In urban areas, wetland-protection rules put the skids on draining and covering up swamps, and that left wetlands and surrounding woods intact. The result was more edge next to homes sporting ornamental shrubs and gardens that attract hungry deer.

Norton and Frelich argue for a policy of trimming the herd size — leaving the DNR between them and sport-hunting advocates like Johnson and Perich, who say that what’s really needed is to address forest fragmentation and things like restricted hunter access and recreational feeding that make deer a nuisance. Cornicelli said ecological effects are considered in managing game herds, but he added that it’s largely a social issue involving a balance of competing interests that must always include the politically active hunter groups.

Minnesota has a long tradition of sport hunting, and last fall 500,000 folks donned their blaze orange and took to the woods. They spent some $500 million pursuing their sport, and contributed $20 million in license fees to fund DNR’s wildlife management efforts. 

Ron Way, a former reporter for several Midwest newspapers, covers the environment and energy issues. He can be reached at rway [at] minnpost [dot] com.