Laura Erickson's For the Birds

Sunday, July 8, 2007

What to do about deer?

I love deer. They're beautiful animals, and when I see a fawn I can feel my pupils dilate. I would feel brokenhearted if I hit a deer with my car, and am bummed out for the day and never seem to forget the sight when I drive past a dead fawn. But that isn't to say that there aren't too many deer. It's just to say that I don't know what to do about it.

I'm not a hunter. When I was a little girl, I consistently scored better than my older brother when we'd shoot his BB gun at targets and tin cans, but he'd always win our tournaments because I refused to even aim at any target shaped like a person or animal, much less shoot at living birds or frogs or turtles. I do not disapprove of sport hunting (as opposed to taking down 70 or 80 pheasants and an undisclosed number of Mallards on a game farm, which I consider an unsporting massacre). I wrote my essay, "About Hunting," about my own struggles to reconcile my personal revulsion toward blood sports with my admiration for Peregrine Falcons and other hunting animals and my respect for many hunters.

No matter what our feelings about hunting, the reality is that there are way too many deer, leading to habitat degradations that are most certainly exacerbating population declines in many species. My guess is that deer play a role in the declines of American Woodcock and Ruffed Grouse both by damaging ground vegetation and by eating eggs and chicks. An essay by Patrick Durkin in the Green Bay Press-Gazette discusses careful research done in Wisconsin 50-60 years ago by John T. Curtis, a University of Wisconsin botanist, who documented the plant communities in 1,400 habitat sites across Wisconsin between 1947 and 1960. Researchers recently revisited 62 of those sites and followed Curtis's methodology, documenting a nearly 20 percent loss of native plants, a slow rise in non-native plants, and less overall variety in plant species. Durkin notes in the Green Bay Press-Gazette article,
Not surprisingly, the biggest impacts were caused by white-tailed deer. Whitetails aren't known to run about the forest, shovels in hoof, replacing native plants with exotics, but their diet preferences determine which plants thrive or suffer.

As deer eat away vegetation that pleases their palate, the plants that take over are typically "generalists" such as native ferns, sedges and grasses. Deer turn up their noses at those plants. In addition, invasive plants like hemp nettle, orange hawkweed and Kentucky bluegrass also take hold.

The most intact, diverse plant communities remaining from Curtis' era grow where white-tailed deer are kept in check. The best examples are on Chippewa and Menominee Indian reservations, where deer numbers are usually half of what roams surrounding lands.

The most ironic finding was that two of the three study sites suffering the largest hits to plant communities were inside state parks, where no deer hunting was allowed. Imagine that. We set aside large areas to reduce human disturbance, but allow almost all recreation except hunting, and let plant communities take a pounding by hungry deer.

Those who protest every time the DNR opens a state park to limited deer hunting should keep that in mind.

But before anyone talks too smugly, they should realize few — if any — people would have noticed those shifts in the forest's plant communities if Curtis and his colleagues hadn't documented what they found 50 to 60 years ago.