Come late November, most of us have turkeys on the brain. But a different type of turkey is taking to the skies at this time of year on its annual migration south: the turkey vulture (Cathartes aura). You can spot them in the sky or on the ground in the Lake County Forest Preserves in northern Illinois.
Everyone has one! At least, anyone who regularly hikes in the Lake County Forest Preserves in northern Illinois has one: a favorite trail. It might be the trail near your home or the one that reminds you of a secret only-I-know-about-this spot growing up. Maybe it holds a special memory. Whatever the reason, something about it always sparks joy in your heart.
For me, most days on the job consist of time in my “office” outdoors—a woodland, prairie or wetland in the Lake County Forest Preserves—with my “clients”—students, teachers, and families interested in learning more about local nature. On those rare days spent plunking away at a computer indoors, the photo above is my view. Recently, this view is bustling with activity, as hordes of ruby-throated hummingbirds buzz around the feeders, bulking up for a long flight south.
My family went on a bike ride last weekend at Ray Lake Forest Preserve. All afternoon, rain sputtered on and off as the clouds played tag with the sun. After climbing up a steep hill, the sky darkened again and we sought refuge under a canopy of large oak trees. One of my sons yelped,”Ouch! That raindrop hurt!” We quickly realized it wasn’t a raindrop, but a storm of acorns jiggled loose by the wind, plopping down on us. The trail became littered with acorns, and the kids began grabbing them. Upon inspection, the boys noticed tiny round holes in many of the acorns—evidence that these nuts were homes to acorn weevils (Curculio spp).
Last week as I was leading a group of adults on a fall color hike, our collective gaze turned quickly from the canopy of coppers and golds to the forest floor as we watched the flurry of chipmunk mischief unfold. We huddled around, marveling at the energy of these charming rodents.
Even though Illinois recently received a break from this summer’s heat and drought, the precipitation deficit that remains statewide has kicked off autumn with atypical natural events. Thus far, the year 2012 has been the fourth driest on Illinois record. However, it has been raining acorns and fall colors have been peeking through the greenery since late August—three weeks earlier than usual. This fast-forward to fall is a tree’s way of protecting itself when water is in short supply. The vibrant color displays of autumn, which seem so lively, are actually a sign that a tree is entering dormancy.
These flashes of fall colors are a result of changes in pigments. The dominant green pigment in leaves is chlorophyll. The leaves in a tree are like little factories, mixing together a recipe of specific ingredients (sunlight, carbon dioxide and water) to make food for the tree’s growth. Chlorophyll acts as the “chef” in this process, called photosynthesis; its presence is necessary in bringing everything together.
Typically, autumn’s cool nights and shortening days trigger photosynthesis to slow down. The scarcity of one key ingredient, water, is triggering this earlier-than-average dormancy. As the work of the leaves comes to an end for the year, chlorophyll breaks down and reveals yellow and orange pigments that have hidden behind its green cloak all summer. Leaves that contain the pigments xanthophyll and carotene—as do hickories, cottonwoods, elms and some maples—will change to vivid shades of yellow and orange as the green fades. Continue reading →