I parked at the Big Rock visitor station this morning just after 5:15. Robins had been singing as I rode through the neighborhoods, but here it was quiet and just a little windy. I walked east, over the bridge at the edge of the parking lot and into the white oaks. The oaks here are large, and there is a gap perhaps 30 feet in diameter that I hadn’t noticed before. Up the hill to the east, the white oaks gave way to red oaks and sugar maples, though I’m not sure how clean this break is. My first impression was that I had gone abruptly from a stand of all white oaks to a slope of red oaks, but as I walked it back and forth, prowled around the woods checking trees, I decided that there was probably a more gradual transition here that would be worth coming back to in the daytime. I’ve become more aware as I grow older that I’m susceptible to my first impressions, and I’m trying to get into the habit of lodging them to look at more closely later on. This transition is one of many such.
Two chorus frogs called from the little valley that runs between the main trail east of the Big Rock Visitor Station and the Woodland Trail to the north. I walked downslope to hear them and got interested in the sedges on the slope. They were evident as dark breaks in the leaf litter even in the twilight. These were the narrow, dark-green leaves of Carex jamesii, I believe, though the clumps were not as dense as I recall finding with Sebastian in these woods in late January. The leaves were still evergreen; I didn’t see any fresh shoots coming up, but I expect them very soon. The two frogs called on, and I stumbled back to the trail.
A woodcock circled over the trail to the south, just east of the large field cleaved out of the forest, where I have collected senescent milkweed stems for the Cub Scouts to make twine bracelets. He flew high, kissing and whistling, then was silent as he dropped back to the ground. I couldn’t hear him peent, and I suspect I was lucky enough to catch him at the end of his dancing. While it’s possible that he dropped to the far side of the hill where I couldn’t hear him, I believe that particular sound carries too well to miss over such distances. It would be fun to map the soundscape of the East Woods through the year: woodcocks and chorus frogs, chickadees, nuthatches, robins, barred owls, then suddenly warblers and field sparrows, then vireos through the summer, then cicadas and katydids, then crickets and grasshoppers, then the sounds of geese flying overhead, then winter again. The problem, I think, would be integrating over the particularity of the place: this woodcock here at 5:30 on March 6, 2017; the next day quiet, then a barred owl the day after, all at the same time of the morning. Would you plot the probability of each sound by time by volume by location? Would it be a four-dimensional soundscape, crammed with piecharts colored by sound? This could be a person’s life work.
I passed the bridge at the east end of the woods, crossed the road for the second time and got to the trail running west from the southeast corner of the woods. The chorus frogs have been most clear here, and today was no exception, but I also heard what I thought was a single spring peeper. I tramped south to try to find it, and I found not a single spring peeper, but a whole pondful of them. I had completely forgotten about the wetlands between the East Woods and the berm. These are fairly typical, weedy wetlands of the upper Midwest, ringed with the Phragmites and Phalaris that was brought in to stabilize creek edges and roadsides. There was a little bur oak along the edge of this pond, and the spring peepers were deafening. I listened for a few minutes, then walked up to the berm overlooking the interstate. From there, I could hear cars and the chuckling of a robin, but no frogs. An Aramark sign was lit up across the highway. You could drive this highway for decades, have been to Lisle 100s or 1000s of times for breakfast or a walk at lunchtime, and have no idea there were spring peepers cavorting in this pond. I walked back toward the trail. The spring peeper calls became deafening again. A song sparrow called. Back toward the trail, the peeper calls attenuated and then were out of earshot. You could miss them even on a walk through the woods.
Twilight had given way to morning. I continued west through P8, through the oak collection—leaves are still hanging on the little post oaks and jack oaks I’ve been watching—and around to the wetland where I’ve been listening to woodcocks the past two weeks. Nothing. Not even a frog call… maybe one, a squeaky thing, but then nothing. The wind had picked up again. In the wet meadow downhill from the geographic collections, a few peepers were still calling. A broad-leafed grass—orchard grass, I suspect—was pushing up young, rubbery first leaves. An elm was flowering.
Further on, burned dropseed bases pimpled the banks of Meadow Lake. The hazelnut catkins hung, about a third of them pendant, fully or nearly fully open. Outside the visitor center, all the elms were flowering, and it appeared to me that fruits were beginning to form. Mt. Fuji early spirea was in bloom, as was Cornelian-cherry dogwood. Male redwing blackbirds were at their treetop stations. Construction sounds floated over from the new building at South Farm. Folks were working in the research building, cleaning and getting ready for the day. We were just 10 minutes by foot from bucketloads of spring peepers and armsful of woodcocks, but you might never know it.
— March 6, 2017