As my winter legs pumped hard on my summer bike, I tried to analyze the contents of each huff and puff of air entering my lungs. From the gritty pavement and slumping roadside drifts came the metallic, dusty smell of pulverized road sand. While not exactly the fragrant perfume of spring I was hoping for, it was still a novelty for awakening senses. The swamps seemed strangely quiet, though, since the dawn chorus of thrushes, veeries, vireos, and warblers has not yet arrived. I made do with the raucous noise of a crow.
Just a couple days later, after a fully-thawed night, I stepped out into a morning thick with the aroma of rotting leaves and breathing soil. The pale lavender sky seemed gentler than usual in this warmth, softened by the return of humidity. On logs and stumps where the snow had already slipped away, green mosses shone with damp triumph at the return of liquid water. I couldn’t resist reaching out to pat one particularly fuzzy patch.
Sharing the moss’s rock were a few little clusters of pixie cup lichens. Pale green, living goblets only half an inch tall sat ready for a banquet among a delicate cluster of squamules (tiny cornflake-like scales). They were damp and pliable. The crustose lichen coating the rock also felt damp and slippery. Nearby, though, on a higher log, some leafy foliose lichens still felt brittle and dry as they waited patiently for spring rains to follow the melt.
“Lichens master the cold months through the paradox of surrender.” observed David George Haskell in his wonderful book “The Forest Unseen.” As I wrote last March, lichens don’t fight the cold, dry, winter air. Lichens allow themselves to gain and lose water as the relative humidity fluctuates. During dry spells, a lichen thallus (leaf-like structure) might only contain 15-30% water, and it goes dormant. Freezing temperatures don’t seem to bother them.
With as little as 60% relative humidity (it’s up to 84% today), moisture will seep back into their cells, the surface will become translucent, and photosynthesis can resume within minutes. “Plants shrink back from the chill, packing up their cells until spring gradually coaxes them out. Lichen cells are light sleepers. When winter eases for a day, lichens float easily back to life,” wrote Haskell.
Lichens aren’t my only northwoods neighbors easily awakened by a few hours of sun and warmth. A five-fingered track pressed into slush bore witness to the passing of a restless bandit. “So that is what I saw,” I thought to myself, remembering the flash of black and gray who scurried out of my headlights the previous evening.
Raccoons spend so much time fattening up during the summer and fall that they don’t need to go into hibernation, nor do they need to cache food to hold them over. With 50% of their bodyweight in fat, they can get by without significantly lowering their metabolism or body temperature through the winter. Month-long naps suffice. During warm spells, they wake up easily (just like the lichens) and may try to raid the refrigerator.
And their refrigerator is large. According to Sam Zeveloff, zoology professor and author of “Raccoons: A Natural History,” “the raccoon may well be one of the world's most omnivorous animals.” Their spring and summer diet consists of insects, worms, bird eggs, fish, amphibians, and small mammals. Fall brings calorie-dense fruits and nuts that facilitate the buildup of winter fat stores. Overall, their diet consists of about 40% invertebrates, 33% plant foods, and 27% vertebrates.
One of the myths surrounding their eating habits is that raccoons wash their food. When they catch aquatic food – like crayfish, frogs, mussels, etc.—raccoons do often examine the food in their front paws before eating. It isn’t about washing, though, but about identifying. Raccoons’ hyper-sensitive front paws are covered by a thin, horny layer that becomes pliable when wet. Tiny hairs nestled near their claws even allow raccoons to identify something before fully touching it. To process the abundance of information from their hands, extra brain space (more than any other animal studied) is devoted to interpreting tactile impulses.
My neighborhood raccoon might have trouble finding open water for foraging and feeling right now. But spring is rushing in, and soon the sun, rain, and returning life will provide all of us with abundant stimuli for our awakening senses.
For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! The current exhibit, “Nature’s Superheroes—Adventures with Adaptations,” will remain open until March 2015. “Lake Alive!” will open May 1, 2015.
Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com.
|Photo by Darkone, Wikimedia Commons|