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Field & Street

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Last Saturday about 175 people gathered at Oakton Community College to learn about nature in the Chicago area. All of us who were there are part of the Volunteer Stewardship Network, a group started a little more than a decade ago by the Illinois Chapter of the Nature Conservancy. The network now operates all over the state, but most of the people in it live and work in the six counties of the Chicago metropolitan area.

The idea of the network is to provide volunteers to help manage natural land. The VSN has cooperative arrangements with the county forest-preserve systems, the conservation district in McHenry County, the state, and federal agencies. The conservancy recruits, organizes, and trains people, and the land-holding agencies tell them what to do. Thousands of volunteers are involved at various levels of intensity. Some just show up for occasional workdays. Some get so wrapped up in the work that they change professions. Some have been inspired to earn degrees in botany, environmental education, landscaping.

Last Saturday's event was a one-day stewards' conference--a chance to hear from experts about everything from a Wisconsin study of small mammals in prairie remnants to the best methods for reestablishing populations of shrubs and small trees in savannas and woodlands. The formal program included 22 separate presentations. Of course at any event of this kind a whole lot of the learning goes on between classes and over lunch. There is a lot of knowledge and a cumulative total of hundreds of years of experience in the group, and people are always happy to tell you what they have been doing--what has been working and what has failed to work.

The active involvement of thousands of volunteers is one of the distinguishing features of natural land management in the Chicago area. Even though most of those present did not have degrees in biology, the level of expertise was very high, and the presentations were often at a level comparable to those at conferences of professional scientists.

The day started with a keynote address by Eric Metzler, president of the Ohio Lepidopterists Society, a group of enthusiasts that has recently assembled an atlas of the lepidoptera of Ohio. With small grants from Ohio's nongame tax checkoff to cover expenses, the members of the society volunteered their time to record range and habitat information for all butterfly and moth species that currently occur in Ohio. This is a fauna that includes about 150 species of butterflies and several times that many moths. In the process of cataloging Ohio's scale-winged insects, the volunteers discovered dozens of species new to science.

I went from hearing Metzler's story of heroic volunteer efforts to listening to Joe Neumann tell how he arranged to have a prairie moved to Marquette Park. The prairie used to live around 87th and Kedzie in the Ashburn neighborhood, which is where Joe lives. He had been visiting it for several years when a developer bought it and announced plans to cover it with houses.

Ashburn prairie was wet mesic--not wet enough to make it a wetland, a classification that would have made it protected. It was far too small to be of interest to the Forest Preserve District. The Park District couldn't afford to buy it, but officials did offer to move an acre of it to Marquette Park, where it can now be seen along the eastern side of Kedzie.

The move was planned for the winter of 1992-'93. A winter move, while the plants were dormant, was thought to be less stressful for them. Also insects and other invertebrates would be all tucked away for the winter, so they would come along too.

Unfortunately the winter was warm. The ground stayed soft and muddy, so muddy that a truck with a huge steel basket couldn't get in. It was May before the job got done. The basket, made of separate steel strips that curved inward toward the bottom, pushed into the earth and scooped up huge plugs of plants, roots, bugs, and dirt about four feet deep and three feet across at the top. The plugs were carried off to Marquette Park, to be inserted into the holes left when plugs from the park were carried off to be inserted in the former home of the prairie. The developer didn't want to wind up with less dirt.

The plugs were set in typical park lawn, filling holes spaced like those in a muffin pan. Fortunately 1993 was a very wet year, so the Marquette Park prairie got off to a good start. Since then Neumann has been working to expand the prairie from the plugs to the places between them. The Park District has seeded another one-acre plot next to the transplants. No species were lost in the move, and the prairie is growing.

I next heard about a small-mammal monitoring project underway in prairie remnants in southern Wisconsin, where volunteers are helping check on the well-being of assorted shrews and rodents. After lunch I listened to Brad Woodson of the McHenry County Conservation District talk about birds in Glacial Park. Glacial Park is a 2,800-acre complex of prairie, savanna, and wetlands undergoing major restoration. McHenry County has pulled out vast amounts of drainage tile to return the land to its former status as a sedge meadow and marsh.

Wetland birds very quickly recolonized the land. Least bittern and yellow-headed blackbird are among the endangered species that have returned. In the prairie sections, the nesting population of the threatened Henslow's sparrow has jumped from two pairs to eight. The endangered northern harrier has moved in too.

Northern harriers were very much a part of Bill Glass's presentation on grassland birds. Glass is a natural-heritage biologist for the Illinois Department of Natural Resources. He has been studying grassland birds at Goose Lake Prairie State Park and at Midewin National Tallgrass Prairie.

Continentwide, grassland birds are believed to be declining faster than any other group of species, even the neotropical migrant forest birds whose problems have received a good deal of attention. In Illinois prairie birds did fairly well in the days of generalized farming, when practically every farm had a pasture and a hay field that the birds could accept as a reasonable substitute for the prairie that had been lost. But in the 1950s a sudden change in farming practices occurred. Farmers began specializing in corn and soybeans, and the former pastures and hay fields were all plowed. The loss of birds has been staggering. Bobolink numbers dropped more than 90 percent, and the others are close behind.

Grassland birds tend to be strongly area sensitive. They will not nest in small open fields, even though they use only a few acres as a nesting territory. Grasshopper sparrows are only a few inches long, but one pair will not nest in any field smaller than about 30 acres. Henslow's sparrows like even larger spaces. They are rarely found in grasslands smaller than 100 acres. Studies on the nesting success of prairie species have shown that nest predation near tree lines at the edges of fields is twice as high as it is in nests far from trees. The birds' preference for wide-open spaces may be a sound survival strategy.

Given the precarious state of these grassland species and their need for lots of space, bird conservation is a matter of considerable importance on the few large prairie and grassland tracts left in the region. Bill Glass has found, for example, that Henslow's sparrows prefer grasslands that have not been burned in three or four years. Other species have different preferences. Glass's recommendation is that three- or four-year burn rotations be established so that there will always be habitat that is freshly burned and habitat where large amounts of plant litter have accumulated.

Many of our surviving prairies are tiny. Glass thinks that no grassland birds will use a grassland smaller than about 25 acres. At sizes below that, no matter what you do, you won't attract any.

The last session I attended was an extended look at our reptile and amphibian populations and the ways that ecological restoration and management affect them. Ken Mierzwa of TAMS Consultants is the reigning local expert on the Chicago area. Like Brad Woodson, he talked about Glacial Park, where restoration has stimulated huge growth in populations of tiger salamanders, smooth green snakes, and many other herps. According to Mierzwa, this ecological management and restoration has made possible real increases in amphibian populations--and there are few such examples in the world. The work of the 175 people at the conference is one of the few bright spots in the globally gloomy trend toward major reductions in the numbers of these animals. His cautiously hopeful words seemed a fitting way to close the day.

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