Fenning in the Rain

Bluff Spring Fen in Elgin, IL photographed by Ernie Constantino.

Fens are a distinctive type of wetland and are among the rarest natural communities to occur in northeastern Illinois. Their defining element is that they are nurtured by water rich in calcium, in contrast to bogs whose waters tend to be acidic. These waters are in shallow aquifers or lenses in limestone or gravel and form seeps or springs. They support a number of plants and insects that are rarely, if ever, found elsewhere. Fens, around here at least, are in fact too small to harbor distinctive vertebrates, so they are not of great interest to birders, except to the extent that the adjoining vegetation provide general habitat for a range of species.  (I hope my blogging boss won’t object but this post looks to be my least birdy blog so far.)

 Two of our most iconic fens both occur near Elgin, Illinois, a city on the Fox River that straddles Cook and Kane counties. Trout Park is the more ignored of the two, while Bluff Spring Fen has a large and talented cadre of active volunteers who take meticulous care of it. I visited both on August 7, due to the interest of two friends (who did not even know each other- nice to have friends who independently want to visit a fen). Ernie Constantino works on environmental matters for Chicago Alderman Mary Anne Smith; we usually manage one field trip a year. And Lynn Rotunno is a graphic artist who spends much of her time furthering environmental protection, particularly with respect to water related issues. I see Lynn a little more frequently, as she lives in a nearby suburb. Being with the two of them proved to be the treat I thought it would. 

Lynn Rotunno and Ernie Constantino in Trout Park, Elgin, IL.

Trout Park, at least the dedicated nature preserve, consists of wooded ravines that slope downward towards the Fox River. The ground is seemingly porous, as mineral laden water percolates to the surface throughout. On the upper stretches we saw muddy puddles but as we descended on the zigzagging boardwalk the water increased in volume and clarity to become distinct streams.  A central fold was lined with skunk cabbage, an unusual plant that thrives in seeps. (The flowers open as early as February and they produce heat to melt the surrounding snow, thus making themselves available to pollinating beetles attracted to their fragrance of rotting carrion)  During late April and early May, Trout Park is at its most colorful as young skunk cabbage leaves of vibrant green share the wet earth with brilliant yellow marsh marigolds.

  But even in the somber tones of thick shade, and on a day when the cloudy sky was heavy with rain, Trout Park offers a beauty born of rarity (the only wooded fen in the entire state), cold crystalline waters harboring insects not otherwise found this far south, and the majesty of white cedars. (As early as the 1850s, the site was referred to simply as “Cedar Swamp”) There is also sadness here, at least for those who know that I-90 bisected the site, destroying 13 acres of the richest ravine.  But we felt no sorrow as we tarried beneath the cedars, entranced by this boreal relict. We were engaged in a tactile way, as Ernie and I followed Lynn’s example of scooping the chilled liquid with our hands, and aurally as we were enveloped in the soft murmuring of the rivulets that seemed to carry us far from where we started.

Perhaps ironically, it was also water, albeit in a different configuration, that prompted us to head back to the car. The rain increased as we retraced our steps, but a calling great crested flycatcher remained undaunted. Unfortunately, I never was sure about a suspected warbler high in the canopy and silhouetted against the dark gray sky. (It would have been my first migrant warbler of the fall)

 The rain continued unabated during the time it took us to reach Bluff Spring Fen. Lynn and Ernie both donned rain jackets. The best I could do was squeeze into the way-too-small rain jacket that Sulli Gibson had left in the car the previous week.  It did cover my arms and shoulders (let us ignore one’s distended abdomen- really a bad case of kwashiorkor, admittedly of very rare occurrence in the Chicago suburbs) but it did provide a little protection for my binoculars. Alas, however, all the precautions were for naught: between the rain coming down and the rain-drenched vegetation of the fen, we were soon soaked head to toe.

 Bluff Spring Fen is a matrix of fen and prairie, situated on and around a series of kames (gravel rises created by the receding glaciers). It is a highly scenic location with lovely floral displays that change throughout the summer. I was there earlier in the season when the purple prairie clover and lead plants were in full bloom. The fen also hosts an unusually diverse array of butterflies (perhaps in part because one of the stewards is Doug Taron, one of the region’s foremost lepidopterists), but on this day the insects laid low and the observers did not dally much.

 In the car, I admitted that I was a bit chilled, which I rarely am. (Ernie’s car has heated seats, and as the temperature rose, I could almost hear the sizzling of my soaked bottom) Lynn volunteered that she was freezing. Having long vowed that no one will ever get hypothermia on one of my August field trips, I had Ernie turn up the heat as we headed towards a taqueria offering both caliente and picante. Relief arrived in the knick of time, for I am happy to report that all participants survived, despite having to endure being damp longer than they would have liked.   (But not so long that mildew became an issue- at least as far as I know)