September is the kindest month. A month when electric bills are going down and gas bills have not yet begun to go up. A month when mosquitoes are dying off but butterflies are still with us. A time when migrant songbirds enliven every backyard and parkway and the last flowers of summer are in full and glorious bloom.

Prairies are showy now, and the richer Illinois woodlands are just as spectacular. Flowers and butterflies will not be with us much longer; now is the time to see them.

I spent a few hours recently walking the trails through Poplar Creek prairie. It was a sunny morning, and a cool breeze from the northwest rustled the tall grasses. They are all in flower now, golden yellow anthers releasing pollen to the wind. They are also truly tall now, with flowering heads more than six feet high. At one point I had to push aside the stalks of big bluestem crowding in from each side of the narrow path. This is a real Illinois experience, pushing your way through grasses higher than your head. It is an experience hard to come by in the contemporary Prairie State.

Migrating monarch butterflies accompanied me on my walk, flitting from goldenrod to sunflower in search of nectar. Yellow is the dominant color of the prairie flowers in this season, although a few rough blazing stars were around to provide a purple accent.

The bobolinks that nest on the prairie have already left for Argentina, but a few savanna sparrows and eastern meadowlarks were still around. A red-tailed hawk perched on a tall snag in the patch of trees at the north edge of the prairie. As the day warmed and the thermals started rising, the hawk soared over the prairie. He was joined by three turkey vultures, birds whose six-foot wingspans made the red-tail look tiny.

The vultures nest at the Max McGraw Wildlife Foundation near Elgin. Turkey vultures were long absent from Cook County, but within the past ten years they have returned. In addition to the McGraw birds, there are two or more pairs in the Palos preserves. It would be interesting to know what they are eating, or more precisely, where they are finding the dead bodies they are eating. Roads are the obvious places to look for dead animals in this area, but roads are heavily populated by large metal objects moving at speeds in excess of 60 miles an hour. A careless scavenger feeding on roadkill stands a good chance of becoming roadkill.

Crows can handle this dangerous job, but compared to crows, vultures are clumsy and slow. They also don’t like roads running through deep woods, where overhanging limbs might block their escape. Our resurgent vultures must be finding enough to eat on open ground away from roads.

The Poplar Creek prairie restoration began in 1989. The land selected for the project had been either cropland or pasture for almost a century and a half. A handful of prairie plants hung on along old fence lines, but the ground was dominated by Eurasian plants. Weedy as it was, the grassland was big enough–close to 150 acres–to support populations of prairie birds. Most prairie restorations have been small, and nearly all of our surviving prairie remnants are also small. You can’t have an ecosystem on a scattered collection of postage-stamp refuges. Poplar Creek was among the few restorations that could operate on a landscape scale, with self-sustaining populations of both plants and animals.

In 1989 a farmer hired for the job plowed and disked a series of 16 strips in the old fields at Poplar Creek. The strips were 18 feet wide and 40 feet apart, and they curved in sinuous arcs across the landscape. Laid end to end, they would stretch five and a half miles.

In spring 1990 the strips were disked again before being seeded with a mix of prairie species with a heavy emphasis on grasses. Since 1990 the areas between the strips have been sown with prairie species with a heavy emphasis on wildflowers.

In September you can stand on the slope of the hill that rises at the northern edge of the prairie and plainly see the plowed strips. They are marked by the russet and gold of the prairie grasses. I am hoping to live long enough to see the strips and the unplowed land between them blend into a rich mixture of prairie plants.

In September the woods at Cap Sauers Holdings in the Palos area are alive with elm-leaved goldenrod, snakeroot, and joe-pye weed. I took a hike on the Visitation Esker, a lovely glacial feature deposited, according to some authorities, during the last advance of the Wisconsin glaciation into northeastern Illinois. Others date it much earlier.

Eskers are meandering ridges built of deposits left by streams flowing under the ice. The flow of the water is usually not heavy enough or fast enough to carry sand and gravel, so these particles dropped out to form the esker. Few eskers survive, because mining them for sand and gravel can be very profitable.

The Visitation Esker was mined at its northern end, but the rest of it supports a lovely oak woodland bordered by marshes in the low spots along the ridge. A path winds along the crest of the ridge, and the woods are open enough to provide good views to either side. From the southern end of the esker the path climbs onto the high moraine through a grove of stately oaks before entering a small prairie. This prairie is one of the loveliest spots in the state of Illinois. It is one of the few places in Cook County where you can escape traffic noise, and if you catch the flight patterns at Midway and O’Hare just right you may not hear any airplanes.

When I visited the prairie was rich with prairie dock, showy goldenrod, and Jerusalem artichoke. Small bur oaks and black oaks, hardy survivors of prairie fires, were scattered over the land. A turkey vulture, one of the Palos nesters, soared in the cloudless blue sky.

This has been a good year for big birds in the Palos area. The turkey vultures are increasing their numbers, and the ospreys successfully fledged three young. These fish-eating hawks nested near Bergman Slough in a snag–a standing dead tree–that toppled soon after the birds abandoned their nest. An osprey nest is a huge construction of sticks that might weigh several hundred pounds, so it is not surprising that the tree could not support it indefinitely.

The three fledglings are the first known osprey young produced in the county since 1855. Plans are now under way to provide nesting platforms for these spectacular birds next year. The Palos preserves are large enough and contain enough open water to support two or three pairs of ospreys.

This year also brought confirmation of nesting by sandhill cranes at Cranberry Slough Nature Preserve in the Palos area. Confirmation came in the form of a face-to-face meeting between Dennis Nyberg, the volunteer steward at Cranberry Slough, and a three-foot, flightless baby sandhill.

Entering the prairie at the crest of the moraine, I followed a path downhill into an oak woodland rich in late-season wildflowers. An intermittent stream flows–when it is flowing–northward through the woods. Before large-scale settlement, watercourses like this one played a major role in shaping the landscape. They provided fire protection for areas in their lee and a humid environment for species that could not survive on the drier uplands.

Along this watercourse I found a lovely example of the shaping influence of the stream. Within a meander bend where the stream provided fire protection to the south, west, and north grew the only sugar maples in the woods. They were big trees. They survived years of wildfires, and since 1981 they have survived prescribed burns deliberately set to maintain the health of the woods.

If you put a stop to fires in these woods, they lose their connection with the land. In this particular woods the sugar maples would probably spread from the meander bend and eventually displace the oaks as the major trees. The small variations in the landscape that support small variations in vegetation would lose their distinctive qualities. The swamp white oaks growing in the scattered low, wet places would be replaced by yet more sugar maples. The small openings in the woods where the clusters of tickseed sunflowers seem to turn the air golden would close in. The great spangled fritillary butterflies that accompanied me on my walk would find nothing to feed on. The variety that delights our eyes and ears on a sunny September day would be gone.