Tuesday, November 26, 2013

Inhale beauty. Exhale gratitude.

Sharply cold air flooded my lungs when I stepped outside this morning. A fresh dusting of snow glittered where the morning sun filtered through trees, and that same sun shone on rosy clouds in a blue sky. I took another breath. Inhale beauty. Exhale gratitude.

Crunch…crunch…crunch. With sunflower seeds cupped in my outstretched palm, I walked to a spot in between the thicket of balsam fir trees and the empty bird feeder. The trees were silent – frozen by my movement. The hyperactive hopping of a single chickadee broke the stillness. Within seconds, the whole flock was back.

During the summer, black-capped chickadees focus on their mate and their chicks. Even if I didn’t have to take my feeder down because of the bears, they would not gather like this for a group feast. By late fall, chickadee flocks are well established and ready to defend a winter feeding territory. One territory just happens to include my feeder.

Like wolf packs, chickadee flocks have alpha and beta pairs at the top of the hierarchy, other mated pairs below them, and then unmated juveniles at the bottom. Unlike wolves, the juveniles are not the offspring of pairs in the flock. Instead, their parents kicked them out of their childhood range in the hopes of spreading genetic diversity a little wider.

As I stood there, hand outstretched, I listened to the interactions of the flock. Dominant birds responded with aggressive gargles aimed at lower-ranked birds who got too close, or disputed the ownership of a seed. Researchers have found that the gargler almost always wins the fight. Shy “tseet tseets,” from hidden chickadees maintaining contact with the flock filtered through the thick boughs. Chickadee-dee-dee calls could have been greetings to friends, or warnings about the possible danger of my presence.

The whirr of wing beats also filled the air as chickadees swooped bravely over my head to the empty feeder, then on to perch on the broom handle near the door, to cling to the side of the porch pillar with needle-like toes, and then back to the safety of the fir boughs. None flew to my seed-filled hand, although I hoped very intently.

Why wouldn’t they jump at the chance to eat a few more seeds? In order to maintain their normal 108-degree body temperature, chickadees must eat the caloric equivalent of 250 sunflower seeds each day. They gain up to ten percent of their body weight in fat each day, and burn it off each night to stay warm.

Maybe the chickadees weren’t hungry enough to brave my hand because they were raiding their cached food instead. Norwegian researchers found that the tit, (a chickadee relative,) caches up to 80,000 seeds in a single autumn. Unlike red squirrels, who put all their seeds in one stump and then have to defend them fiercely, chickadees spread out their seeds singly, and don’t worry about a few getting stolen.

If I were a chickadee, my biggest source of seed loss would be my own forgetfulness! Chickadees have it figured out. They use forgetfulness to make space for new memories each year. Each fall, brain neurons containing old information die, and new neurons grow with current information about seed locations, social flocks, and their habitat.

This also means that they have forgotten my past role as a harmless provider of food. My hand throbbed with cold, so I stuck it back in my mitten and walked down to the lake for a break. Those rosy clouds and that blue sky sat reflected in a section of open water, surrounded by a skim of ice.

I continued down the driveway, stepping over the leaping tracks of red squirrels, the tiny bounds of mice, and the snowed-in trail of a midnight fox. All these brave creatures share the winter world with the chickadees and me.

Scooping seeds out from the tip of my mitten where I had stored them, I tried again. Standing silently, hand outstretched, I waited. Again, the flock began swooping around me, but not landing. Then a different movement caught my eye – a vole was foraging at the base of the dead spruce.

The instant that my focus left the chickadees for the vole, I felt the spiny grip of a chickadee on my finger. Not daring to shift my gaze and scare it off, I kept my eye on the vole, and my awareness in that finger. I took a deep breath of crisp air. Inhale beauty. Exhale gratitude.

Now the spell was broken. Several more chickadees swooped down to grab seeds. In between, I was able to look down. One chickadee cocked its head and peered up at me through a shiny black eye, as if to say, “I see you. You’re ok.” That was all I wanted.

“Sometimes I need only to stand wherever I am to be blessed.” 

― from Evidence, by Mary Oliver

It’s Not My Track

Despite the gray skies, despite the chilly wind, I needed a hike. Already, this early winter weather and lengthy darkness has me down. Bike season is over for my sensitive toes, ski season taunts me from just around the corner. I could have curled up on the couch with a book, but I lured myself out to the trail with memories of other times that a walk in the woods has done me good.

An inch of snow covered the grassy, soggy ski trail. Movement felt good, but my mood still clung. Soon, I began noticing tracks: the daisy chain of a grouse’s small steps; the dots and lines of a mouse dragging its tail; the lacy pattern of a shrew’s diagonal walking gait; the funny little half-tunnel of a vole burrowing along the top of the grass.

The large, loping tracks of a fisher made me stop and look. Then, barely ten steps down the trail, the belly-slide marks of an otter made me laugh as I imagined his playful mode of travel.

In summer, the woods bustle with life, but the comings and goings of little feet are hard to decipher in the thick grass and leaves. The first snow primed the forest’s typewriter, and now the paw-and-claw-inked words are preserved for a moment, allowing me to read their stories.

Still, the cabin fever was persistent. Mouse tracks became routine, and above trudging footsteps, my mind turned inward.

Then, out of the corner of my eye…WOLVES! While my thoughts had been elsewhere, my eyes registered the big, four-toed paw prints scuffing the snow across a whole section of trail. I grinned, my mind now alert and senses primed. A quick survey of the scene allowed me to estimate: definitely four, probably five wolves. Mary Oliver’s poem, Bear, comes to mind: “It’s not my track, I say… to no one but myself, since no one is
with me.”

Maybe you think I should be nervous, walking in wolf-filled woods alone. I am not. Having tracked wolves in several different places (Minnesota, Yellowstone, Wisconsin), and observed them for hours on end (they mostly slept), I am confident that their wildness and skittishness of humans keeps me safe.  I am ok with any risk that remains.

Instead of nervous, I am thrilled. I love seeing evidence that such graceful, powerful predators inhabit these woods. I love knowing they are here--running easily, determinedly, playfully through the forest. Perhaps if I had livestock, or dogs, or children I would feel differently. Perhaps that’s why I don’t have them…

When Mary Oliver describes discovering the bear track, she hints at all sorts of reports she’s heard of other people’s bear encounters. Then she goes on to say, “But not one of them told what happened next-I mean, before whatever happens-how the distances light up, how the clouds are the most lovely shapes you have ever seen, how…every leaf on the whole mountain is aflutter.”

After seeing those tracks, I felt alert and alive. For the rest of the hike I peered into the woods. Leaves fluttered. The clouds flushed pink in the setting sun. Nothing else happened. No wolves let me see them.

Too soon, I crossed my own large boot tracks near the trailhead. As I neared my car, I stored this hike away in my memory for use on another day when I need an extra something to lure me out for a walk in the woods.

“In every walk with nature, one receives far more than he [or she!] seeks.” – John Muir

For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI, at 13470 County Highway M. The current exhibit, “Deer Camp: A Natural and Cultural History of White-tailed Deer,” opened in May 2013 and will remain open until April 2014.

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/.

Friday, November 15, 2013


I love things that help me get a new perspective on the world, so I always request a window seat. Taxiing to the runway, my face pressed to the clear plastic window, I watched a flock of snow buntings swoop in unison above the grass. White flashed on their wings. There was grace in the unconsciousness of their flight.

Birds are so well adapted for travel through the air that their movements can seem effortless. Even when we see how hard they are working, the power in an eagle’s wings and the skill of a hummingbird’s maneuvers fill us with a sense of awe. Human-designed flight was not so easy.

In the years since Icarus flapped his waxy wings toward the sun in ancient Greek mythology (and fell into the ocean when they melted), humans hadn’t had much luck trying to copy birds. Paradoxically, the great success in human flight came when we stopped trying to mimic natural flyers and began designing from scratch, says Professor Spedding, of the University of Southern California.

Now there I was, ready to take to the air, casually fulfilling the dream of flight with millions of other people today. We turned down onto our runway and sped up. As the force pushed me back into the seat, I imagined what it must be like to be a loon – running hard across the lake, splashing and pushing with broad feet, until finally achieving enough speed for liftoff. Even when I was no longer jostled by the bumps of earth, I was still pressed back into my seat by the acceleration.

Loons have the heaviest wing-loading of any flighted bird, so they, like airplanes, must gain speed in order to generate enough lift to leave the ground. They must maintain that speed, too, or risk a crash landing. Have you ever seen a loon fly slowly? Me neither. Also like commercial airliners, loons need their wings mostly for long-distance trips, and use wide-open spaces for take-off and landing. This allows both planes and birds to survive with limited maneuverability.

I’m likewise fascinated to see a bird’s-eye-view of the landscape – to follow familiar rivers, highways, lakeshores and forests in an effort to understand them from a new perspective. Today, however, my view was blocked as we rose through a thick layer of bright white clouds.

Thankfully, the pilot has a sophisticated instrument panel that helps guide our course. Birds, too, have a sophisticated set of tools for navigation. Besides using landmarks during the day, they use the rotation of the stars, the orientation of earth’s magnetic field, and the angles of polarized light at sunset.

New research from the Max Planck Institute for Ornithology in Seewiesen, Germany, has added weight to the hypothesis that homing pigeons (and probably other birds, too) use smell to navigate home. Every place smells a little different, and breezes coming from different directions carry that information to the pigeons. The birds can essentially create a smell map in their head that helps them navigate back home. Amazing! But I’m still glad my pilot is using a GPS.

Although humans only achieved flight when they stopped trying to copy birds, now that we’ve figured it out, engineers are looking back at the more experienced flyers to solve all sorts of problems. For example, jet aircraft engines used to “choke” at supersonic speeds due to air moving around the engine instead of through it. The peregrine falcon – which can dive at over 200 mph – provided a solution. Specialized cone-shaped bones near its nostrils, called baffles, deflect shockwaves of air and allow peregrines to keep breathing. Jet engines now have similar cones in their engines.

Despite the clouds, we found Chicago, and with our loon-like limited maneuverability, swung wide over the lake to start the landing pattern. As we slowed down to land, the plane used another bird-like feature on the wing. Nearing the ground, slats on the front of airplane’s wings dropped down. According to Wikipedia, this “allows the wing to achieve a higher than normal angle of attack – and thus lift – without resulting in a stall.”

On a bird, the alula--a small projection on the leading edge of the wing--serves the same purpose. It is essentially the bird’s thumb, and its three-to-five feathers can be moved freely. When flying slowly or landing, the bird can move the alula slightly upward and forward, giving it the same advantages as the airplane slats in slower or higher-angled flight.

Future airplanes may use a sharkskin-like paint job or butterfly scale-like coverings to reduce drag. Seabird-like moveable wings might improve efficiency with gusts. Humans continue to look to nature for more ways to improve our flight. Even rubber made from Kazakh dandelions may one day provide a more sustainable material for landing gear.

As the old-fashioned rubber tires bumped onto the runway beneath me, I was grateful for the chance to view the world from a new perspective. But I realized that my relatively effortless trip was made possible by years of innovation – just like the snow buntings’ effortless grace came only after eons of evolution.

For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI, at 13470 County Highway M. The current exhibit, “Deer Camp: A Natural and Cultural History of White-tailed Deer,” opened in May 2013 and will remain open until April 2014.

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/.

Friday, November 8, 2013

A Dandelion Smile

A chilly breeze whipped around my head. Even a pale sun peeking through racing clouds did not seem to improve the temperature. Head down, I hurried toward the post office. Then, a spot of color made me stop and smile. A single yellow dandelion and its star of vibrant, toothy leaves nestled into the snow-flattened grass.

I’ve always loved dandelions. They popped up every summer in the kingdom of make-believe that was my yard, and created a sea of sunshine in the farmer’s hayfield across the back fence. Every spring I still pick one of the hardy flowers to give to my mom for her late April birthday. Unless I’ve flattened it in a card to send through the mail, she still sticks dandelion in a little vase on the sill above the kitchen sink.

As a kid, I continued picking dandelions all summer long. I’d split the stems lengthwise and watch as they coiled into beautiful curlicues when dunked in cold water. I soaked the fuzzy blossoms in water and made “lemonade” that I never drank. I almost hyperventilated while trying to blow every parachuted seed off the stem to make a wish. And every t-shirt I owned was stained with little brown circles from the juicy stems.

Even today, despite my awareness that dandelions are invasive weeds, I can’t help admiring their tenacity. And I’m not alone. Buddhist monk, Thich Nhat Hanh, shared this poem (written by a student) in his book, Peace is Every Step.

I have lost my smile,
but don’t worry.
The dandelion has it.

So I smile whenever I see those cheerful weeds. Sometimes I even brave their bitterness and eat young leaves in salad. Other folks swear by the sap as a remedy for warts or foot fungus. Turns out, the dandelion may be more useful than I ever imagined!

The Kazakh dandelion (Taraxacum kok-saghyz, a relative of the one in your yard), is an excellent source of natural rubber. The milky sap in the root is so high in latex that one field of dandelions produces as much latex as the same size plot of rubber trees. In addition, the quality of dandelion latex is exactly the same as latex from a rubber tree, and can be substituted one-for-one in the rubber formulation. To top it all off, dandelion latex does not seem to trigger allergic reactions!

Russians discovered this amazing dandelion in the early 1930s, in Kazakhstan. They tried to develop it as a domestic source of rubber. During World War II, when the Japanese controlled the supplies of rubber from Southeast Asia, researchers in the United States, Germany, Sweden and Spain all jumped on the dandelion-rubber bandwagon. In the U.S. alone, land grant universities in 40 states conducted research on this lowly plant.

Most research came to a halt after the war ended in 1945. Today, an internet search for dandelion rubber reveals that at least three separate tire companies are partnering with research institutions to make this new source of rubber viable on a commercial scale. Germany's Fraunhofer Institute for Molecular Biology and Applied Ecology is working with Continental. Bridgestone is working with the Program for Excellence in Natural Rubber Alternatives at Ohio State University. Multinational tire manufacturer, Apollo Vredestein, also thinks dandelion rubber has potential, and is collaborating on the project with KeyGene.

Despite the many benefits of dandelions – they grow like weeds on many soil types, reproduce like weeds with lots of seed, and thrive in northern climates instead of sub-tropical forests – there are some obstacles, too. Dandelion juice transforms from a liquid to a solid on contact with the air – a process known as polymerization. This means that processors must use turpentine to chemically extract the latex from dandelion roots.

To eliminate the enzyme responsible for polymerization, German scientists at the Fraunhofer Institute engineered a special virus. According to a Discovery News article, “Once inside, the virus deleted the offending genetic sequence from the Russian dandelion's DNA. Pop the head off an infected dandelion, and the latex begins to flow freely.” (Watch out, Mom!  My shirts will have more than just little brown circular stains!)

It worked. But in Europe, creating transgenic dandelions is pretty controversial. Now German researchers are using traditional selective breeding techniques to accomplish the same thing. At the same time, Continental is working with the researchers to build the first ever commercial-scale processing plant. (Hopefully they are also developing ways to make sure the super-seeds don’t escape into our yards!)

Maybe in the future, that field of dandelions across the back fence won’t be full of weeds. It will be full of a cash crop, harvested by the same machines used to pull tulip bulbs. The sticky sap, once a stain on my shirt, will instead help my airplane land safely in Germany so I can go for a ride in a car with dandelion tires. That might even make me smile.

“What is a weed? A plant whose virtues have never been discovered.”

--Ralph Waldo Emerson

The Weird Ones

The scent of snow fills the air, and the hissing plops of wet snow falling off the trees fills my ears. The woods, and its inhabitants, are transitioning between fall and winter. It’s the same for me, as I jog down the road in my summer hat and winter gloves, wishing for ski season to arrive.

Early fall was a time of vibrant colors and lots of action. Colors have faded a bit now. If you have lived in the north for a while, you may have come to appreciate the subtle gold of a tamarack swamp, or the rich browns in an grove of oaks as they extend the fall color season. But have you ever stopped to think about how weird those two trees are?

Tamaracks are conifers, bearing their seeds in cones just like their relatives the pines, spruces, and firs. But conifer isn’t our first choice for describing pines – we’d rather call them evergreens. When we do that, though, tamarack doesn’t fit. It is the only deciduous (losing its leaves seasonally) conifer in Wisconsin. Oaks, in contrast, are in a group known as broad-leaf trees, most of whom are deciduous. Yet oaks cling to their leaves.

Why would a tamarack lose its needles? Why would a pine keep its needles? And why does the oak keep its dead leaves?

There is adaptive value in each strategy, otherwise they would not persist. Needles are really just modified leaves, better suited to low nutrient, low moisture situations. They have basically the same parts as a maple leaf, but everything is more tightly packed and protected. The stomata (pores for gas exchange) hide in a groove, protected from dry winds. A waxy outer layer helps to prevent water loss. By retaining green, chlorophyll-filled leaves all year, evergreen trees can take advantage of any warm days to photosynthesize, and save themselves the trouble and nutrient expense of growing new leaves each spring. They replace only about a third of their needles per year.

On the other hand, broad-leafed deciduous trees, like maples, grow large leaves with a lot of surface area for photosynthesis. The broad leaves also result in a lot of water loss. This is fine when it is raining, but not when it is frozen. Although trees use enzymes to protect leaves from freezing while they are still photosynthesizing, that only works for so long. Then, frost-damaged leaves would be a liability as an entrance for disease.

Why would tamarack combine the two strategies and lose its needles?
Well, we don’t know for sure, but my favorite theory is that it has something to do with how far north the tamarack’s range extends. On the Winter Solstice this year, Duluth, MN, will only have 8 hours and 32 minutes of sun. In Fairbanks, Alaska, near the northern edge of the tamarack’s range, the sun will shine weakly for 3 hours and 42 minutes. Most of the tamarack’s habitat is in the middle of that range. What good are green needles if there is little sunshine? By building more delicate needles that don’t have to withstand harsh winter conditions, tamaracks can save a little energy.

Likewise, what good are the dead, brown leaves of an oak, even with sunshine? Oaks are a broad-leaf tree, but, oddly, they hang onto their leaves until heavy snow knocks them off, or until new leaves push them out. Most deciduous trees (including tamaracks) cut their leaves off by growing a protective abscission layer on the end of the twig, and then encouraging the leaf to skedaddle with digestive enzymes or a new layer of cells.

In contrast, oak leaves start to grow an abscission layer soon after new leaves form, but do not finish the process until the next spring. Scientists call this retention of dead stuff “marcescence.”

Plant physiologists agree that marcescence is a juvenile trait, associated with young trees and newer branches. This makes sense, since the young aspens in the field near my house are still holding onto their leaves. And understory trees, which tend to be younger, always seem to change colors later in the fall.

Marcescence also may be juvenile in terms of evolutionary history. In southern regions, some oaks are evergreen. Our northern oaks may be in transition from being fully evergreen to being fully deciduous. Maybe they are not done yet…or maybe they like where they’ve paused!

Although there are tasty new buds waiting to come out in the spring, this year’s dead, dry, crinkly oak leaves are not very palatable, and that may deter deer and moose from nibbling on the new growth. The tardily deciduous aspens probably gain that benefit, too.

Another hypothesis is that the oaks are saving their leaves until spring. When the leaves fall, they will provide the tree with nutrient-rich mulch for the growing season, instead of the leaves decomposing throughout the winter. The leaves dangling from lower branches may also act as a snow fence, trapping extra moisture for the tree.

Of course, there is no way for us to know for sure just what the oak is “thinking” as it rustles its skirt of leaves in the middle of a blizzard. Nor do we understand what the tamarack is “planning” when it turns golden, and then bares its knobby twigs for the winter.

As with humans, the weirdest organisms are often the most interesting. At least, that’s what I hope, since some of you probably think I’m weird to be wishing for ski season in October!

For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI, at 13470 County Highway M. The current exhibit, “Deer Camp: A Natural and Cultural History of White-tailed Deer,” opened in May 2013 and will remain open until April 2014.

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/.