Friday, June 26, 2015


A pungent, earthy, vibrant aroma seemed to squirt out of the bog with every sinking footstep. Even through the soles of my muck boots I could enjoy the varying textures of this living carpet. Soggy sphagnum moss offered almost no resistance, while the skeletons of tough twigs buried within the moss crackled, bent, and snapped. At some point in each footfall, the cushion of living and dead plants pushed back toward me just enough so that I didn’t fall through.

Bogs are a unique, almost alien landscape, with a charm all their own. Funny plants, few trees, and a wonderful, squelchy, squashy, shaky, shivery, sucking substrate can turn adults back into giggly, wiggly kids. These twenty-two Wisconsin Master Naturalist Volunteer trainees were no different as they spread out to explore the Secret Bog.

Squatting down next to a domed hummock, I peered into a miniature jungle. Delicate vines of bog cranberry – with bright pink, swept-back petals on their tiny flowers; the wiry lattice of leatherleaf twigs; and bog laurel’s leaning stems with deep green leaves all poked their heads out of the mat of sphagnum moss like drowning rats. Sphagnum moss may be the bog’s bully – pulling itself up on the stems of others, using woody plants like scaffolding – but it is also the reason that the bog is here.

Sphagnum’s primitive leaves are like tiny sponges, and can absorb up to 26 times their own weight in water. This can raise the water table. Such a saturated environment is low in the oxygen that microbes need to accomplish decomposition, so nutrients stay locked up in dead vegetation. To deal with the lack of available minerals, sphagnum shoots hydrogen ions into its environment, dislodging scarce nutrients for its own use. This acidifies the bog, which further limits what plants can grow there.

Life is not easily discouraged, though, and a special suite of plants thrives in sphagnum’s world.

Peering over the side of the hummock, a sparkle caught my eye. Looking closer, I discovered a cluster of bright pink, hairy spoons, only an inch or two high. “Sundew!” I squealed, pulling over the nearest student naturalist to exclaim about it with me.

Round-leaf sundew are beautiful little plants, with a circumboreal distribution (around the Northern Hemisphere), and a penchant for animal flesh. Well, a taste for insects and spiders at least.

Sundews love the sunny, moist habitat created by sphagnum, but they still need to eat. Nitrogen is a limiting nutrient in bogs. Some plants get their nitrogen through complex root systems and relationships with fungi, while others conserve it with the austerity of evergreen leaves. Sundews catch bugs.

The sparkle that caught my eye was actually a drop of “dew” clinging to the tip of a tiny tentacle. The bowls of sundew’s spoon-shaped leaves are dotted with these tentacles. Long ones hold a drop of sweet, sticky nectar that attracts and entraps prey. Once an unsuspecting insect has been mired in this mucilage, the leaf curls inward. This response to touch is known by the comical term: thigmonasty. From the bug’s perspective: thing most nasty.

Death usually occurs within 15 minutes, as the prey succumbs to exhaustion or is suffocated by the goo. Shorter tentacles, with drops of digestive enzymes at their tips, make contact with the prey and reduce it to nutrient-rich soup, which is absorbed through the leaf surfaces. The valuable nitrogen is use to make chlorophyll, enzymes, proteins, and seeds.

The seeds are produced in a delicate, white-petaled flower held aloft on a long stalk. But how, might you ask, does the insectivorous sundew avoid eating its own would-be pollinators? In nature’s wisdom, a completely different set of bugs is attracted to the flower from those who are lured in by the saccharine dew.

The group of students was lured in, too, a few at a time, to look at the impressive patch of sparkling leaves. As we headed back to solid ground for our closing discussion, I plucked a little cluster of sundew leaves to bring in for a closer look. At first I was annoyed when the tentacles stuck stubbornly to my finger. Then I chuckled at my own surprise. It seems that Master Naturalists are no more immune than bugs to the cloying charms of sundew.

Friday, June 19, 2015

Chicken of the Woods

“Did you see that giant chicken!?” exclaimed my co-worker Jayme as she stepped out of her Jeep in my driveway. My puzzled look must have answered her question. “There’s a huge chicken of the woods right next to your driveway! It’s bright orange. I can’t believe you missed it!”

Jayme’s excitement was warranted. Chicken of the woods (a.k.a sulphur shelf) are choice edible mushrooms, and she is an enthusiastic mychophagist (mushroom-eater) and wild forager. A little embarrassed that I had missed such a neat find, I joined her and Steve, her partner, on a quick hike back up our long gravel drive. “I won’t tell you where it is,” she teased, “let’s see if you can find it yourself.”

Once I was looking, it wasn’t hard, but I did discover why I hadn’t seen it before. Tucked away up a steep bank, several yards back in a balsam thicket, the cluster glowed orange on the cut stump of a fallen tree. We grabbed baby birch stems and kicked our toes into the dirt, clambering up the near-vertical road cut.

It was impressive. Nearly two feet across, with layer upon layer of rippling brackets giving it a ruffled appearance, the yellow edges and undersides contrasting with rich, orange caps – this mushroom was beautiful.  It is also unmistakable. David Arora, author of “Mushrooms Demystified”, includes chicken of the woods in his “foolproof four.” Upon closer inspection, we found that the cluster was fresh, clean, and flexible. Just ripe for eating.

We reached into the mass, and gently tugged free a few of the most fresh and tender looking caps. The flesh was cool and moist to the touch, with a texture like fine velvet. Part of this consistency comes from it being a polypore. Unlike stereotypical mushrooms with the umbrella-like cap and radiating gills, polypore mushrooms are composed of many small, vertical tubes. Reproductive spores are produced on the sides of the tubes, and use gravity to disperse out of the bottom opening. From there, the spores use wind and animals to disperse them into a new home, eventually growing more mushrooms.

The pore structure also contributes to the succulent, stringy texture of the caps, which reminds some people of chicken meat. Soon we had tugged free enough caps to share with everyone for dinner.

Cooking mushrooms is extremely important for both safety and nutrition. Heat can denature toxins, kill nematodes, and break down tough cell walls to give our bodies access to nutrients. After wiping off a few specks of “trail spice,” we added the orange caps to a warm skillet in a pool of melted butter and garlic. With a lid to help keep in the juices, the “chickens” were soon sizzling merrily.

The first bite was the best: chewy but tender, with a light lemony undertone and a touch of the savory umami flavor, too. Though we wanted to keep eating, each of us tasted only a couple of small pieces. Chicken of the woods causes mild stomach upset in some, and allergic reactions in a very few. With any wild mushroom, it is best to try only a little at first, to gauge how your body will react.

After a comfortable night, I headed back to the stump to collect more. The wood still looked solid, so I suspect that this fungus will be back again next year. Chicken of the woods is a parasite (it kills trees) and saprobe (it decomposes dead trees), most commonly on oaks. After years of decay, it renders the wood – especially the heartwood – into a friable mess of brown cubes. Until then, it may fruit in the same place year after year.

And until then, I will continue making it part of my dinner. As I pulled off more chunks for my skillet, I noticed slugs and flies dotting the yellow undersides of the brackets. In just a few days, its brittle flesh would be riddled with insects, slug trails, and beetle holes. The fungus will die back. The decomposer will decompose.

The tree feeds the fungus. The fungus feeds the animals. Eventually the soil will feed a tree. And somewhere in that cycle, is me.

Chicken of the Woods, Photo by Emily Stone

Saturday, June 13, 2015

Old Turtle

The old turtle scraped at the sand with her naily toes as the kids gathered in a wide circle around her. Sometimes I get questions about dinosaurs on field trips, but they don’t fit into the Museum’s focus on Northern Wisconsin species. Today, instead, the first- and second-graders got a close-up look at a creature who has existed on Earth for over 40 million years, with direct ancestors much older than dinosaurs.

Quietly and respectfully, the students observed as the mother slowly finished excavating a depression for her precious cargo at the edge of the boat ramp’s asphalt. We commented on her smooth, algae-covered shell and enormous claws on her webbed feet. Once, I caught a glimpse between her hind leg and knobby tail of a smooth, white eggshell sliding into the nest.

The size and age of a female snapper, and the number of eggs she lays each year, are all connected. A mother turtle will only lay a clutch of eggs equal to about 7% of her body mass each year, and some years not at all. This helps make sure she’ll have enough energy to survive the winter, and translates into somewhere between 11 and  87 eggs, with an average of 34 eggs per clutch in northern populations.
Because of this trend, female snapping turtles don’t mature until they are eight inches long -- big enough support a clutch of about 22 eggs. With our short growing season in the north, that can take 19 years. This big mamma was well over a foot long. How many years must it have taken her to grow that big?

One reason that snappers grow so slowly is that they are ectotherms who use their environment to regulate body temperature. In the summer, they sun themselves to warm up. After a long winter, they have to wait until the shallows reach at least 40 degrees in order to become active.  Even then, they don’t start eating until the water temperature reaches about 60 degrees. This means that in cold northern lakes, snapping turtles may go nine months without eating.

Once they do warm up enough to eat, over half of their diet is vegetation. Snapping turtles are important scavengers, and may improve fisheries by eating the slow, bottom-feeding fish (which are generally unpopular among anglers). Although baby ducks do make the occasional tasty snack, they are a much less common part of the snapper diet than many people think. Over the course of a year, a snapper will only eat its own bodyweight in food. That isn’t a recipe for quick growth.

One consolation for their stingy diet may be that snapping turtles rarely become food for something else. The eggs and little guys are vulnerable, of course, but once their carapace reaches three inches long, they have no more natural predators.

Getting there is the tough part.

The eggs we just watched being laid have almost no chance of reaching maturity. For one, their location at the edge of a driving surface is pretty risky. But even in a good location, only about 14% of clutches hatch each year. Nest predation, temperature variation, and dehydration are all constant dangers.

Temperature is especially important. The embryos won’t develop at temperatures cooler than 68 degrees Fahrenheit. Above that, interesting things happen. Because turtles evolved before x and y chromosomes, they developed a system to use temperature to determine the sex of the babies. At 83 degrees Fahrenheit, the number of males and females will be equal. Cooler temperatures will produce males, and higher ones will develop females.

It is amazing that this lumbering matriarch even survived to this point in time. But turtles are survivors. Fossils of the most primitive turtle put the age of this group at 215 million years old – about 100 million years older than dinosaurs. Turtles survived the meteorite impact and the dinosaurs’ great extinction.

Reluctantly, the students left the great mother to her important task, and began one of their own. With nets and enthusiasm, they caught critters in the weedy shallows. Soon a shout rose above the rest, “I caught a turtle!” With its spiky shell, just over an inch long, this new stage in the life of a snapper – a baby hatched last year – captivated their attention just as thoroughly as the one before it.
This baby snapper, caught the same day, must have hatched last year. It gives hope for the future. Photo by Emily Stone

Friday, June 5, 2015

Broad-winged Hawk

The blade of my hoe cut easily through the garden soil, loosening the roots of pesky weeds so that I could remove them entirely from the bed. Tomorrow I hoped to plant carrots here, and I wanted their tiny seeds to have a good place to start, so that their tasty orange roots can grow deep without competition from weeds.

The first high, piercing whistle barely tickled my consciousness. But the second “tee teeeeeee,” and then the third made me look up. Expectantly, I searched the clear blue sky for a familiar shape. I still remember the first day I heard it – while reading Sigurd Olson in the spring sunshine under a tree on the Northland College campus. The faint but penetrating whistle made me look up, then scramble to grab my binoculars.

Still a beginning birder, I carefully noted the broad, pointed wings on this soaring hawk. The tail was most distinctive though. Thick black and white bands made the short tail very conspicuous. After studying my Sibley Guide to Birds for a minute, I landed on an identification of Broad-winged hawk.

Since that day, that distinctive call has penetrated my awareness many times. Each time I hear it, and always look up to find that distinctive tail silhouetted against the blue. Sometimes, in September, I’ll look up and see hundreds of broad-wings all swirling in a kettle as they migrate en masse to Central and South America. Their group migration is famous, and dependent on thermals. Because they rely on the rising warm air of thermals to save energy on the long journey, all broad-wings on this continent need to fly south around the same time in the early fall when the sun is still high and thermals are common.

Today there was only one hawk, surfing a hot wind as it whipped around the hedge of pines along the road. Swooping up and down, it cavorted acrobatically with only imperceptible tilts of its wings. Broad-winged hawks are said to avoid human development, but they also seek small forest openings in which to hunt. Somehow the agreeable configuration of trees and clearings along the road must have outweighed the homes and cars nearby.

Perhaps the proximity of Perry Lake (where my elementary school field trips have found many frogs and tadpoles recently) also helps sweeten the deal for this amphibian-eating raptor.

After a minute of admiring the single hawk’s antics, I caught a glimpse of another dark shape among the trees. Two broad-wings! Was this a pair engaging in a courtship display? If you’re in the right place at the right time, you might see a display that includes cartwheels, dives, and breathtaking, foot-joined tumbling.

The birds moved out of view behind the trees before I witness any such magic, but still I hope that they will have a nest nearby.

If they do, the larger female will lead the process of placing sticks for a nest, with some help from the smaller male. It can take two to four weeks to construct the nest, thirty days to incubate the eggs, and eight weeks for the chicks to become independent.

Turning back to my hoe, I concentrated once again on preparing a nest for my carrots, looking forward to the day when they, too, will grow big and strong, and fledge from this cozy nest of soil (into my kitchen!)
The most distinctive feature of a broad-winged hawk is actually the stripes on its wide tail. Photo by New Jersey Audubon.