The beginning of a breeding-bird survey is like the beginning of a love affair. You just know that this time it's really going to work. Other springs may have yielded the banalities of robins and redwings, but this is certain to be the year of Cooper's hawk nests and hummingbird fledglings.
This year, Somme Woods is the site for my own battle between hope and reality. I'll be spending the next few months combing this 150-acre preserve, looking first for singing males and then for nests, eggs, and young. My sober, scientific goal is to identify every nesting species and get a solid estimate of population levels for each. My dream is to discover strange and wonderful rarities, extraordinary birds that have not been known to breed in Cook County since 1908.
I feel some pressure to find these wonders. Volunteers from the North Branch Prairie Project have been hacking away at Somme Woods since 1981, cutting brush, planting seeds, pulling out weeds by hand, one plant at a time where necessary. Somme, the largest of the seven sites the project is restoring along the North Branch of the Chicago River, is rapidly evolving into a re-creation of the prairie and savanna landscape that existed here before we chased out the Potawatomi. I'm hoping the birds will supply validation for all this effort, proof that the work is worthwhile. I'm going to be very disappointed if years of hard labor turn up nothing but more robins.
The Return of the Bluebirds is currently feeding my dreams. I saw them on March 18: two males hopping from branch to branch in a clump of small trees near the north end of the preserve. The blue on their heads and backs was so intense they almost seemed to glow. Bluebirds--like blue jays and indigo buntings and every other kind of blue bird--have no blue pigment in their feathers. The color comes from a peculiarity in the structure of the feathers that causes them to reflect blue light. On overcast days, blue birds tend to fade to gray, but on this dark, murky day--it had been snowing a few minutes earlier-- these birds looked bright enough to read by.
A pair of eastern bluebirds nested at Somme last year, and I'm hoping the birds I saw this year were returnees and not just migrants pausing for a rest on their way to someplace else. Bluebirds used to be common all over the eastern U.S. In the days of generalized farming, they nested in natural cavities in wooden fence posts and hunted insects in cow pastures. Contemporary fence posts are made of steel. Cow pastures are much rarer than they used to be, and where they do exist, starlings fiercely contest the rights to nesting cavities.
Bird lovers have been making major efforts--primarily by setting out bluebird houses--to help the species come back. Somme Woods has no nesting boxes, so last year's birds must have found a natural cavity. The oak savannas of primeval Illinois would have been ideal bluebird habitat, providing both trees for nesting sites and open ground to forage on. The return of the birds to Somme suggests our savanna restoration is on the right track. But when I returned to Somme on March 22 I could not find any bluebirds.
The area I am surveying lies west of Waukegan Road and north of Dundee Road. The Milwaukee Road tracks run north and south through the preserve, dividing it approximately in half. Just west of the tracks is a narrow, deep, ugly ditch, all that remains of the West Fork of the North Branch of the Chicago River. What was done to the river is a process called channelizing, a barbarous assault on nature performed in the name of flood control. The water in the ditch looks beaten down and demoralized. In a natural stream, the water seems to speed up in the shoals and slow down in the deep pools, to race around the wide bends of the meanders and linger behind dams created by downed logs. In the ditch, it all moves at the same unvarying pace, like a formation of prisoners plodding around an exercise yard.
You can still trace the natural meanders of the old bed of West Fork through the dense, buckthorn-infested woods west of the ditch. This time of year the natural bed even has some water in it, but the water doesn't flow.
The area west of the tracks is flat. A little less than half of its 70 acres is covered with junky second-growth woods with a buckthorn understory. My experience has been that you don't find much variety in the bird life of a woods like this.
The other half is open grassland. At the heart of this is a high-quality prairie that has been designated an Illinois Nature Preserve. The NBPP has been steadily cutting away at the woodland and planting prairie seeds in the grasslands. Eventually, according to the management plan, all that will remain of the woods will be a thin strip along Dundee Road whose function will be to keep off-road vehicles out.
Everything else west of the tracks will be prairie, a re-creation of the presettlement state of the land. Our prevailing westerly winds used to carry the fires across the prairie. They would burn down to the west banks of rivers, and then be halted. Where they burned, prairie dominated the land. In the lee of the rivers, forest or oak savanna could thrive.
East of the tracks, in what was once the lee of the river, you're on the Deerfield Lobe of the Lake Border moraine. The land rolls in gently sinuous shapes, sloping down from the high point at Waukegan Road toward the former location of the West Fork.
Moraines as young as this have undeveloped drainage patterns. Instead of the precisely defined creeks of mature landscapes like the Ozarks and Appalachians, here you find ponds on hilltops. There is one right next to Waukegan Road at the highest point in the preserve. Water collects in swales, low places that sometimes widen into ponds and then narrow into sluggish streams.
I always find more birds of more species on the east side of the tracks. The greater variety in both the landscape and the vegetation provides more possible niches.
So far this year, I have made two visits. After that first snowy day when I saw the bluebirds, I went back on March 22, a pleasantly warm sunny day, and spent three hours in a slow walk through the land on both sides of the tracks.
Within five minutes of my arrival, I flushed two woodcocks from the edges of the brush. Woodcocks are among the earliest nesters at the preserve. They build their nests on the ground, and the nests are very hard to find. The females sit very tight, and their cryptic coloration renders them almost invisible.
The best way to census woodcocks is to visit the preserve just at nightfall when the males are performing their mating display. Singing a twittering song, they spiral high into the sky and then fall like leaves in the wind: a quick drop, a short upward swoop, another drop, another swoop until they return to earth.
I found a large flock of robins feeding on a patch of prairie that had been burned last fall. Fresh green grass shoots had just broken through the black, bare earth. The robins plainly prefer to feed on the burned-over ground rather than on unburned soil. It is probably much easier to find earthworms with the matted duff of last year's greenery burned away.
Flickers were feeding with the robins. These big woodpeckers pass through in some numbers in the spring, but so far I don't know of any that have stayed to nest. I'm hoping they will. Somme should be woodpecker heaven. The NBPP has killed many trees by girdling them, and snags, as standing dead trees are called, are everywhere. Woodpeckers excavate nests for themselves in snags, and bluebirds and many other species move into the nest holes when the woodpeckers finish with them.
I have some hopes for the pair of wood ducks I saw in Oak Pond, one of the small ponds on the moraine. Oak Pond was completely hidden in the woods. Large trees grew right out of the middle of it. These trees have now been girdled, and as they rot, natural cavities of the sort favored by wood ducks should open up in them.
The eastern phoebe I saw in one of the oak groves is probably just a migrant. We are within its nesting range here, but it prefers to nest on cliff faces and similar situations, and Somme offers none of these.
I saw a half a dozen song sparrows. This species will certainly nest here, but so far none of the birds are singing. In fact, the whole place has an unsettled air. Only the resident cardinals are in full song. In the drama of this year's breeding season, we are in act one, scene one. We can't know yet which possibilities will be realized and what new elements will be added later. This is the time to be full of hope.