State wildlife managers are planning a long-term deer study on a parcel of land in the Northern Highland-American Legion State Forest.
Approximately 1,000 acres will be divided into a number of fenced-in areas which will contain varying deer densities. Researchers will study deer densities in relation to forest composition.
The study area will be on what is called the Ontonagon River Block in Land O’Lakes on Vilas County Highway B.
The research area, as planned, will have:
• Three 120-acre enclosures that will contain three deer during the summer and two over winter, simulating a low density of 16 deer per square mile and 11 deer per square mile respectively.
• Three 90-acre enclosures that will hold four deer during the summer and three during the winter which will simulate a moderate deer density of 28 per square mile over the summer and 21 per square mile over winter.
• Five deer enclosed in each of three 80-acre pens during the summer and four over winter, representing a high deer density of 40 per square mile during the summer and 32 per square mile during the winter.
• Three enclosures with no deer at all in them.
• One buck in each enclosure.
(Lower winter densities simulate a fall deer harvest.)
Rhinelander-based DNR research scientist Dustin Bronson said the densities were based on historic deer densities.
He noted this study will differ from ones with other deer enclosures, such as the Cusino enclosure in Upper Michigan and the George Reserve in lower Michigan.
“The Cusino and the George, basically they fenced one area and put deer in and just allowed them to do their thing,” Bronson said.
Those studies have yielded good information on things like population dynamics, but these areas differ from our own, Bronson said. The state wants to specifically study Wisconsin’s northern forest. Also, previous studies haven’t looked at differing population densities.
“That’s something that’s really important,” Bronson said. “How do these specific densities affect our forest and likewise, how does the forest affect that density in terms of health and recruitment?”
The state will be able to test different forest management tactics during the study.
“It seems like when you review the history of deer browse literature and it goes back to the ... late 1930s, early ‘40s with Aldo Leopold, and later Ernie Swift, teaming up together, cruising Wisconsin forests and saying, ‘We’ve got a lot of deer browse damage,’ and then lobbying for lower deer populations,” Bronson said.
“The sportsmen and the resorts – the people who want to see more deer – would lobby back and say, ‘No, no. I didn’t see a lot of deer this year. We need more deer.’ And it’s this back and forth, back and forth.”
Being able to employ different forest management with differing densities of deer will allow managers to better help citizens who are looking to improve habitat on their own properties. Being able to observe things like body condition and antler growth, and relating that to the habitat and its condition will help wildlife managers going forward, Bronson said.
They will also be able to study the effects on other species.
“Is the forest reproducing and getting the diversity it needs so you’re not setting yourself up for some monoculture that’s disease prone down the line,” Bronson said.
New management tools
“We want to create a series of metrics to use for that new deer management program,” Bronson said, noting the sec-age-kill (SAK) model that has been used to estimate deer populations in the past has come under criticism.
One of the things managers will observe is how deer utilize browse and what studying that can reveal about deer populations.
Bronson said learning stuff like that will be “another tool in the (deer management) tool box.”
The enclosures will allow close observation of deer health along with forest health, he said.
There may be ways to use trail cameras as tools to estimate deer populations. Bronson cited such a study on European roe deer that was done recently.
That’s something that could be tested in the enclosures, which will have a known number of deer, Bronson pointed out.
Work soon to be underway
Work on the site could get underway soon.
“This summer, we’re hoping to mark the trees that would be harvested,” Bronson said.
The hope is to have the timber harvested over the 2014-15 winter. By summer 2015, fencing could begin going up, assuming the timber is harvested.
The fencing, which will be 10 feet tall above ground, will also be anchored two feet deep. The current plan is to have the enclosures ready for deer by the winter of 2016-17.
The property, which the state purchased in 2009, is a good area for the study, Bronson said.
“We have some great winter thermal cover that will be preserved, and then we have the ridges of northern hardwoods and then some areas of aspen that we’re going to expand upon as well,” he said.
The goal is to make sure the deer have what they need.
“We recognize the critique that we’re going to be holding deer in enclosures ... between 80 and 120 acres,” Bronson said.
A mortality study area near Winter has provided information, Bronson said. Deer wearing telemetry collars were mapped and wildlife managers were studied the home ranges of these deer to see where they were going and what they were doing. They have also been tracking 10 mature does in Vilas County.
Researchers can get a look at things like how much browse is available and what kind of thermal cover the deer are using on a larger home range. Bronson used the term “stems” to describe browse.
“We’re just calculating based basically on stems per deer,” Bronson said.
“When we adjust our densities in here, you might only have three deer on 120 acres. We can provide them the amount of browse necessary – that a free-ranging deer would have. We also can provide the same kind of winter thermal cover that they would choose.”
Researchers will also have free-ranging deer they are tracking as they study those in the enclosure, which will have GPS collars as well. They’ll be able to compare the habits of the enclosed deer to those of free-ranging ones.
The property was chosen in part because the state gained ownership of it fairly recently and deer hunters and camps are more established in other possible spots. Managed Forest Law lands weren’t a possibility because the law won’t allow an enclosure as large as the one proposed for the study.
“We’re trying to help hunter management, not rile up hunters and get them upset,” Bronson said.
Fawning, disease prevention, predators
State researchers want the does in the enclosures to be bred.
“We want to have a better understanding on how forest management and climate affects population dynamics of our deer,” Bronson said.
Things like how many fawns does are giving birth to and their overall condition in varying population densities are things wildlife managers will be watching closely. They eventually want what they are seeing in the study area to contribute to aspects of deer management like predicting recruitment rates.
Bronson said the enclosure will operate like a cervid farm, with precautions to help prevent disease.
Once a deer is in the enclosure it will not be released, though fawns could eventually be moved to different enclosures to help prevent inbreeding.
The state will test all of the deer in the study for disease. They will also be marked with ear tags and wearing GPS collars. If a deer somehow got out, it could be tracked down and brought back.
The enclosures will be stocked with local deer, but the 36 deer needed will not be taken from one small area, Bronson said.
The fence probably won’t exclude predators. Bears can climb and other predators could tunnel through.
“This is not a predator exclusion study,” Bronson said, noting that the depth of the fence would make for a long tunnel that deer would not want to use to get out of an enclosure.
“We need to test two different things here,” Bronson said. “Not just coming up with the ideal number, but how do we get the number that Wisconsin citizens want. Is there a management scenario we could do to get that number?”
A Pennsylvania study of timber which involved enclosed deer taught managers something about forest health, Bronson noted.
“There was no difference in their forest health and their forest recruitment when they were at zero deer, 10 deer per square mile, or 20 deer per square mile,” he said.
“If you didn’t know that, forest ecologists and timber folks would be saying, ‘We need lower deer, lower deer,’” Bronson said.
The upper limit, as far as range carrying capacity, is something researchers will be looking at.
“At what point does everything just start falling off the rails from an ecosystem perspective?” Bronson said.
But there are considerations other than deer numbers, he said. Some might like to manage for big antlers, or even other species of wildlife.
The study is slated to run 30 years, but could yield something interesting from a scientific standpoint much earlier, Bronson said.
Once it’s ready to go, people will not have access to those acres, but they can check out the project.
“Once it’s built, we will want organized tours to come out. And conservation groups and (people) really to be interacting with this,” Bronson said.
He said the study area could also be used as a teaching tool for people interested in deer and forest management.
“We really want a lot of public involvement once it’s up,” Bronson said.
Craig Turk may be reached at firstname.lastname@example.org.