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  • Writer's picturePatrick Durkin

Research: Biologists Spend Ample Time in Deer Woods

Updated: Jul 25, 2022

One baseless accusation heard again in June during our eternal deer debates is that this biologist or that forester is only “book smart,” and should spend more time in the woods to see what’s really going on.

That’s a common trope for Natural Resources Board members Greg Kazmierski and Fred Prehn, but citizen critics who hunt Bayfield County repeated similar charges last month when demanding the NRB slash the antlerless quotas on public lands.


It’s odd that anyone who can read and write would mock information and education, the most precious, widely shared benefits our society provides. Granted, some bookworms need more sunlight and fresh air, but their critics need more time with books and less time atop their barstools, barber’s chairs or ivory towers.

More relevant reading might make them more receptive and perceptive when in the woods, and keep them from sounding so silly when testifying in public. One book they should borrow from a library or buy on Amazon is “The Vegetation of Wisconsin” by John T. Curtis, a University of Wisconsin botanist who died 61 years ago; July 7, 1961, to be exact.

Curtis compiled incredible amounts of information about Wisconsin’s native plants and plant communities in his brief career and relatively short life. Fortunately for us, he understood the value of documenting and cataloging his observations so those who follow — you and I — might benefit from his labors.

Curtis was 48 when cancer killed him. All the information he gathered would have died with him if not for books. Equally important, of course, is for later generations of Wisconsin botanists to share Curtis’ passion for applying plant physiology to their work, and continue building upon the foundations he laid.

During the late 1990s, for example, a team of UW botanists led by Tom Rooney and Don Waller found Curtis’ original data sheets and punch cards he filled up from 1947 to 1960 to document the plant communities in 1,400 habitat sites across Wisconsin.

Together with fellow botanists Shannon Wiegmann and David Rogers, the UW team located 62 of Curtis’ study sites in the forests of far north-central Wisconsin, as well as scattered sites in the western Upper Peninsula and northeastern Wisconsin. Then they spent lots of time in the woods repeating Curtis’ painstaking work.

When they finished, they compared and documented changes they found in the plant communities over the past 50 years, and published their findings in the May 2004 edition of “Conservation Biology.” Several findings should interest deer hunters, bird watchers, tree huggers and anyone else who values Wisconsin’s forests.

After reviewing the 62 sites, the researchers documented a nearly 20 percent loss of native plants, a slow rise in nonnative plants, and less overall variety in plant species.

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, grasses and invasives. 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 still grow best where white-tailed deer are kept in check. The best examples are on Ojibwe and Menominee Indian reservations, where deer numbers are usually half of what roams surrounding lands.

The most ironic finding in the 2004 review was that two of the three study sites suffering the largest hits to plant communities were inside state parks that didn’t allow deer hunting. Imagine that. We set aside large areas to reduce human disturbance, allow almost all recreation except hunting, and let plant communities take a pounding by hungry deer.

Those who still protest hunting in state parks should keep that in mind.

Likewise, hunters who hunt the same patch of national forest decade after decade shouldn’t be surprised to hear that overabundant herds in the 1990s overbrowsed native plants so severely that they created ecological voids, which were filled by plants deer won’t touch. And when deer can’t find edible food in such places, you can’t force them to live there, no matter how loudly you yell about wolves, coyotes and the mean ol’ foresters.

So before folks claim biologists don’t spend enough time in the woods, they should read Curtis’ book and the follow-up research by Waller and other UW botanists. All the data and observations those folks compiled didn’t fall from the sky.

They noticed and documented those shifts in the forest’s plant communities by repeating the work of John Curtis and his colleagues 50 to 60 years earlier. That means they hiked into the woods day after day, laying grids, and painstakingly documenting what grew inside each.

That’s how science works, folks. We might not be aware of it personally, but that doesn’t mean the research and findings weren’t done and properly recorded for the public’s benefit.

It’s time for people like Kazmierski, Prehn and their fan club stop claiming such work isn’t available, and start reading the volumes awaiting their attention.

When hungry deer eat away forest vegetation that satisfies their nutritional demands, the plants that take over are typically “generalists” such as native ferns, sedges, grasses and invasive plants that deer won’t touch. — Patrick Durkin photo:

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Jul 23, 2022

Your spot on with this article Pat. The work of Curtis/Waller and others well document the negative impacts of whitetail deer on our native ecosystems. Many Wisconsin hunters and several members of the Wisconsin Natural Resources Board need to wake up and understand the importance of using science in managing our natural resources.


Jul 23, 2022

Patrick, your writings are always spot on! It's evident you do your research on every topic. And you make every topic interesting, even if I'm several states away.... Thanks

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