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Wisconsin Natural Resources magazine

Wisconsin Natural Resources magazine

The presence or absence of ground squirrels and other small mammals says a lot about the health of an ecosystem. © Richard Bautz

June 1997

The quiet projects

Lesser-known species and habitats get the attention they deserve when a federal grant program brings groups together to break the silence.

Maureen Mecozzi

The presence or absence of ground squirrels and other small mammals says a lot about the health of an ecosystem.

© Richard Bautz
Neda Mine Bat Sanctuary | Restoring prairies & oak openings
Prairie insect inventory | Small mammal monitoring
Landscape management for prairie chickens | Protecting habitat on Northern Wisconsin lakes
Riparian rotational grazing

A timber wolf's solitary howl, the clarion call of a trumpeter swan, the bald eagle's high-pitched screech: These are the rallying cries bringing together thousands of people on behalf of endangered resources. Listen carefully, though, and through the clamor you might hear more. A breath of wind rustling a Kittentails, perhaps. Or the slow, deliberate progress of a winged snaggletooth snail on the march across a bit of prairie. You might even eavesdrop on half a million bats dozing in a favorite hideout.

For several years, Department of Natural Resources scientists have been listening to a few of our less vocal-and-visible species with assistance from a federal program called Partnerships for Wildlife. Designed to promote the welfare of nongame species, Partnerships for Wildlife offers grants to state fish and wildlife agencies that work together with local governments and private organizations to study, track and support the species and habitats that can't quite command a major constituency.

Partnerships for Wildlife aims to address some of the smaller parts of a larger whole – smaller, but no less important to the overall health of the ecosystem. The program recognizes the value in studying a wide diversity of animals, plants and their habitats. Wisconsin's eight Partnership projects are true blueprints for ecosystem management. All involve people with diverse interests working toward a common goal. Some of the projects span human-made boundaries: With the restoration of a Wisconsin bat hibernaculum, researchers hope to avert a decline in bat populations across several Midwestern states. Other projects review what we already know, to see if it holds up as the ecosystem changes. Prescribed burning for prairies, for instance. Is this established land management method harming invertebrates as prairie habitat becomes increasingly fragmented?

The grants provide the means to expand our base of knowledge about nature, and to adjust and build upon what's already known. So give a listen to these eight quiet projects. You might hear something worth shouting about.

Bat Sanctuary

Where miners once toiled to raise iron ore from the earth's depths, bats now sleep. Lots of bats. More than 500,000 bats of at least four species – including the Little Brown, Big Brown, Long-eared, and Eastern Pipistrelle – find the four-mile maze of tunnels crisscrossing more than 22 underground acres at the old Neda Mine in Dodge County a fine place to hibernate.

So fine that the mine's hibernating bat population ranks as one of the largest in the world. September's shorter days and cooler weather prompt the bats to congregate in the mine, where they wait out the winter until mid-May. The mine's various tunnels, coupled with high humidity (about 100 percent throughout), and good ventilation from adits (horizontal entrances) and vertical air shafts, create micro-habitats in which the different bat species can find the temperature and air flow that best allows them to maintain a low metabolic rate and conserve energy during the long winter's rest.

The Neda Mine was active from 1864 to 1914. After the miners left, spelunkers, vandals and a growing number of bats visited the mine over the years, until, in 1976, the property was acquired by the University of Wisconsin with help from The Nature Conservancy and the Department of Natural Resources. It was designated as a State Natural Area for its value as a hibernaculum.

The mine's entrances had deteriorated with age, threatening to disrupt the flow of air so important to maintaining the micro-climates. Crumbling rock at some openings prevented bats from entering the mine. Vandalism and trespassing continued to be a problem; even low levels of disturbance disrupt hibernating bats.

Biologists recognized the loss of a key hibernating site such as the Neda Mine could affect bat numbers across a multi-state region. But finding the financial backing to restore a mine for bats wasn't easy in an era when smog-choked skies and polluted water supplies topped the public's list of environmental concerns.

Finally, with funds from a Partnership grant, Bat Conservation International, the University of Wisconsin-Milwaukee, the U.S. Fish & Wildlife Service, private citizens and the Department of Natural Resources, restoration began in 1995.

The mine openings were secured with grates bats can pass through ૻ but humans cannot. Some entrances were stabilized to ensure good air flow. Seventy-five feet of unstable rock was blasted out and removed from the main adit, which was fitted with a bat-passable grate.

To match the pre-construction habitat conditions of the mine, DNR scientists monitored the mine's temperature, humidity and air flow before work began in the fall of '95. They are now using that baseline data to note changing air flow in the reconstructed adit, and they continue to monitor the mine's conditions to ensure the bats can hibernate in peace.

DNR Natural Areas Specialist Mark Martin says the restoration was worth a 20-year wait. "If no restoration had been done, the mine likely would have become less and less suitable for bats," he said. "Future bat populations could have been greatly decreased without it."

Restoring prairies and oak openings

Mark Martin emerged from the depths of Neda Mine to work on two other Partnership for Wildlife landscape restoration projects.

The first involves the renewal of dry prairies, savannas and oak woodlands at eight State Natural Areas covering more than 2,000 acres in the blufflands of the Mississippi River. Shrubs and small trees have taken over these former grassy landscapes because the natural fires that once burned back the woody growth are now extinguished, for fear they will harm human life and damage property.

To give a boost to native prairie plants and wildlife, Martin and his team have begun removing woody and exotic species from the sites. Crews are cutting down or girdling buckthorn, elm, red cedar, ash, ironwood and aspen trees, and eliminating patches of sweet clover and leafy spurge. Prescribed burning will then be conducted to maintain the open grasslands.

"We're focusing on ecosystem management, not single species management," says Martin of the ongoing project. Increasing the size and quality of the prairies, savannas and oak woodlands will help threatened plants thrive, including the pale purple coneflower and spiked blazing star. Cerulean warblers, the black rat snake, and a very rare prairie snail – the winged snaggletooth – may again breed on the restored sites. Migrating bald eagles and peregrine falcons will return to find abundant prey in the grassy bluffland prairies.

People will benefit, too. All of the areas are open to the public, and Martin expects improved opportunities for viewing wildlife as the land is restored to its pre-European settlement state.

Martin is guiding a similar Partnership effort in the Southern Unit of the Kettle Moraine State Forest in southeastern Wisconsin. There, the once-common oak opening ecosystem has dwindled to less than 1,000 acres scattered across the region.

The forest's Oak Opening State Natural Area contains more than 600 acres of degraded oak openings surrounding 30 small remnant prairies. Despite the land's current condition, a diversity of native prairie and oak opening species can still be found, including a large population of the state-threatened Kittentails. Clearing non-native woody species like honeysuckle and black locust from the degraded lands will allow the spread of species from the intact openings. Again, fire will be used as the primary maintenance tool after the initial clearing has been done.

It's expected that wild turkeys, Eastern kingbirds, bluebirds and a host of prairie invertebrates will thrive in the restored oak opening habitat. Money for these project comes from a Partnership grant, turkey stamp funds, the Paul Stry Foundation and the Endangered Resources Fund.

"Prairie and savannas once covered millions of acres in Wisconsin, and now less than one percent remain," says Martin. "It's satisfying to know the financial support was available to keep these two restoration projects going."

Prairie insect inventory

The biological wealth squandered when a vast ecosystem shrinks to the size of our remaining prairies makes DNR terrestrial ecologist Rich Henderson wince. "If we are going to retain or restore the natural heritage of our endangered prairie ecosystems," he says, "we have to address the greatest source of biotic diversity in prairies – the insects and other invertebrates."

Unfortunately we don't know much about these very small, very numerous, and very important parts of the prairie ecosystem. For three years, Partnerships for Wildlife, The Nature Conservancy, the Mellon Foundation, the Johnson Foundation Trust, and others have provided funds to help researchers in six Midwestern states get out in the field and count.

It's a big, big job. "We have a very poor understanding of what insect species inhabit prairie, let alone which ones are the prairie specialists," says Henderson.

Volunteers can take part in field research, too. © Richard Bautz
Volunteers can take part in field research, too.

© Richard Bautz

Although researchers are attempting to focus on species most likely to be prairie specialists, the sheer number of insect species found in prairies – from moths, leafhoppers, beetles and true bugs to flies, wasp and grasshoppers – complicates the task. "We are finding species as yet undescribed by science, and hundreds of species are turning up for the first time in a given state," he says. "It's overwhelming." The field work to date has revealed many rare and specialized prairie insects still present on prairie remnants, even on sites as small as half an acre.

Career counselors take note: The work of identifying specimens and revising taxonomic groups could take decades. "There are just not enough taxonomists out there to go around," says Henderson.

Researchers are also discovering that careful use of fire as a prairie management tool does not, for the most part, harm prairie insect populations (though there are some rare exceptions). Because our prairies are now so small and fragmented, some entomologists have concerns about prescribed burning, fearing fire might force prairie-restricted insects to flee to nonprairie lands where they could not survive or reproduce. As the insect inventory progresses, research will also continue into the best strategies for managing invertebrate communities along with the rest of the prairie ecosystem.

Small mammal monitoring

Our ignorance regarding the diversity and distribution of prairie insects is almost matched by our thin knowledge about shrews, voles, mice and other small grassland mammals. Besides feeding hawks and foxes, small mammals play an important role in seed dispersal and influence insect populations, just to mention a few of the reasons to study these little balls of fur.

No comprehensive inventory of small mammal species has been done since H.H.T. Jackson's book Mammals of Wisconsin was published in 1961. Members of the Wisconsin Small Mammal Survey Team include Nicola Anthony, Richard Bautz, Paul Matthiae, Steve Richter and Elizabeth Spencer. These researchers from the Department of Natural Resources, The Nature Conservancy and the University of Wisconsin received a Partnership grant to take a closer look.

They lined up 50 additional pairs of eyes to help. Volunteers contributed about 2,000 hours of their time in 1996 to study six southern Wisconsin State Natural Areas and The Nature Conservancy preserves.

"This was a cooperative effort right from the start, everyone has worked hard to make this a successful project," says Ricahrd Bautz, DNR researcher. "We are about to start our third monitoring season and we rely on volunteer help in the field. For many students and mammal enthusiasts, this is their first hands-on experience with wildlife."

"Volunteer participation was outstanding last year," says Nicola Anthony, graduate student in the UW Madison conservation biology program. "There was an overwhelming level of volunteer commitment to the program."

Using live traps, researchers and volunteers tracked nine target species, including two species of special concern – the western harvest mouse and the prairie vole. The traps were checked twice a day, morning and evening, during survey periods of four consecutive nights, with intervals of six weeks between each survey.

Each captured animal was identified, aged, weighed, sexed and marked with small ear tags or a dab of nontoxic paint behind the ear. By using the mark-release-recapture method, the researchers hope to derive good estimates of the relative abundance of each species, and to monitor the responses of small mammals to grassland management methods. They also intend to refine the survey methods, creating a common protocol so inventories can be conducted in larger geographic areas across different types of landscapes.

The data is now under analysis, but there were a few glaring absences the researchers couldn't help but notice. Only one prairie vole was trapped in 1996, even though traps were located on sites with suitable prairie vole habitat. The least shrew, the pine vole, and Franklin's ground squirrel – grassland species that historically occurred within the geographical area of the study – also failed to appear.

Landscape management for prairie chickens

Talk about one lucky cluck! Nearly 15,000 acres of grassland are maintained in central Wisconsin for the greater prairie chicken. And with good reason: The prairie chicken is an indicator of a healthy ecosystem. Where there's good prairie chicken habitat, the prairie chicken isn't the only species to benefit – other grassland species are likely to be doing well, too.

Private land accounts for nearly 75 percent of the landscape in the prairie chicken's range. Major parcels under public management include the Buena Vista Marsh, Leola Grasslands and the Paul J. Olson Wildlife Area in central Wisconsin.

Good grassland habitat helps the prairie chicken thrive. © Wayne Nelson
Good grassland habitat helps the prairie chicken thrive.

© Wayne Nelson

Grassland habitat is also maintained on the George W. Mead Wildlife Area. The heart of prairie chicken range is just west of Highway 51 from Plainfield to Stevens Point to Wisconsin Rapids. Private lands protect scattered populations of prairie chickens north of Wisconsin Rapids toward Mosinee, west to Marshfield and north toward Medford. In recent years center-pivot irrigation and other intensive crop management methods have changed the landscape. Researchers are concerned that prairie chicken populations may be declining in response.

To get an accurate population estimate, the Department of Natural Resources, the Society of Tympanuchus Cupido Pinnatus and the University of Wisconsin-Stevens Point received a Partnerships for Wildlife grant to continue the annual booming ground survey for the entire Wisconsin prairie chicken range. The range has been surveyed each spring since 1989; Wisconsin prairie chickens have been monitored annually since 1951.

Grant funds were also used to build a GIS (Geographic Information System) database incorporating spring booming ground locations, private land uses, land ownership, habitat types, home ranges for individual chickens, and other elements. The layers of GIS data create maps showing, for instance, which parcels offer the best prairie chicken habitat. Managers use the maps as guides for future land acquisitions. GIS gives managers the big picture so necessary for the landscape-scale management of many individual land parcels.

Offering opportunities for the public to view prairie chickens on their booming grounds each spring has been crucial to generating and maintaining public support for prairie chicken habitat. Grant money made it possible for nearly 1,000 people to visit the booming grounds in April, 1996.

"The public/private partnership has made prairie chicken management work right from the start," says DNR Wildlife Manager Jim Keir. "That sustained partnership has enabled us to evaluate successes and failures from four decades of management. The bird is colorful and vocal. It's a lot of fun to watch and it's a symbol of the native prairies that are now largely gone from the state. Prairie chicken populations remain a barometer of the health of the remaining grassland environment."

Protecting wildlife habitat on Northern Wisconsin lakes

The calm beauty of Wisconsin's northern lakeland has long attracted vacationers, outdoor sports enthusiasts and retirees. In recent years, the ever-growing number of people drawn to reside or vacation in the region has compromised the ecological integrity of many northern lakes.

Loons need quiet habitat to breed successfully. © Stephen Lang
Loons need quiet habitat to breed successfully.

© Stephen Lang

The loss of wetlands and shoreline vegetation, reduced water quality, and declines in fish and wildlife populations are directly linked to the area's rapid development.

Growth is likely to continue in the region for some years to come. Resource managers will need to make appropriate recommendations and decisions if development and recreation are to occur with a minimum of environmental degradation.

The need to accurately gauge how development affects northern wildlife is being addressed by a Partnerships project examining the breeding habits of bald eagles and common loons on developed and undeveloped lakes. The World Wildlife Fund, the North American Loon Fund, the Sigurd Olson Environmental Institute (SOEI) and the Department of Natural Resources are collaborating in the effort.

"It's an attempt to quantify biological change, so we can provide people with a basis for making informed decisions," says Mike Meyer, DNR researcher on the project. "If adequate nesting habitat is protected for eagles and loons, we expect many other shoreline-dependent species will benefit as well."

Loons, eagles and mink require relatively undisturbed lakeshore sites for nesting -- but how much disturbance they can tolerate is uncertain. The DNR researchers will use data gathered from breeding surveys to compare with a model developed by the Ontario Ministry of the Environment. The model predicts when the rate of shoreline development will result in the loss of critical wildlife habitat.

Data from surveys on migrating songbirds, hawks, small mammals, turtles and frogs also will be compared with the model. There's a human element, too – SOEI researchers surveyed lakeshore property owners to gather data on perceptions of lake quality, motivations for ownership, and perceived threats to lake aesthetics. This information will help managers incorporate human values into their recommendations.

The project will be completed in September, 1998. Should the Wisconsin data validate the model, the information could be used to make informed decisions regarding lakeshore zoning and public acquisition of wildlife habitat.

Riparian rotational grazing

The goal: Find farming techniques for streamside agricultural land that will protect water quality, provide habitat for fish and wildlife – and produce income for the farmer.

Due to a thin soil layer and high erosion rates, much farmland in the rugged Driftless Area of southwestern Wisconsin is unsuitable for row crops. The land can support grass and grazing cattle, so more and more farmers in the region are turning their fields to pasture. But cows and cattle wandering down to a stream for a drink erode the banks, and their manure pollutes the water, destroying habitat for fish, frogs, insects, grassland birds and other wildlife.

"Buffer strips along streams provide environmental benefits, but take the land out of production," says Jerry Bartelt, a DNR researcher guiding a long-term Partnerships for Wildlife project. "Plus, buffer strips have to be fenced to keep cattle out, and the fences often get washed out in floods. That's a lot of maintenance and repair work for the farmer."

Farmers' concerns are utmost on Bartelt's mind. Integrating the needs of wildlife into agriculture requires close attention to the realities of farming – profit, loss, time. That's why farmers and ag interests work side-by-side with wildlife researchers, government representatives and others on a committee in search of practical, achievable solutions to an assortment of farming issues.

In the Driftless Area, Bartelt's team is comparing ungrazed stream buffer strips, rotationally grazed pastures, and continuously grazed streamside land to see if rotational grazing can be as effective as ungrazed buffer strips in preventing runoff and habitat deterioration. In rotational grazing, the animals are placed in a small, moveable paddock for one to three days. Then, paddock and animals are rotated to another portion of the pasture. This allows the land in each previously grazed paddock to rest for three or four weeks.

The group is also learning about the streamside habitat that results from rotational grazing. Over time, trees and shrubs may grow into ungrazed buffer strips, while rotationally grazed areas typically remain as grass. The different maintenance techniques produce different habitat, which has implications for the wildlife species the land can ultimately support.

To date, researchers have collected one year of data, including census counts on grassland birds, fish, frogs, toads, small mammals and aquatic insects, and measures of pasture productivity. They'll gather more data this summer; analysis and recommendations will follow.

The search for environmentally sound and financially workable, low-maintenance streamside management methods for farmers intrigues Bartelt. "It's really enjoyable to look for these potential win-win solutions, and then test them to see if they'll work," he says. "It never fails to amaze me – when you begin discussions with people from different backgrounds who have a common interest in a problem, the seemingly insurmountable situations often turn out to have several potential solutions that can meet the needs of most people involved."

Maureen Mecozzi is Associate Editor of Wisconsin Natural Resources.