Friday, December 21, 2012


A brisk wind bit my cheeks as we hiked down the trail. Even bundled up in a puffy jacket and thick pants, with a wool hat on my head and jumbo mittens on my hands, I could not keep my nose and toes from getting cold. Three to four inches of snow crunched loudly under our boots. Most of the dimples in the snow were made from raindrops or tree-falling snow plops, but a few were made by wild little feet.


The daisy chain tracks of a grouse crisscrossed the trail like a holiday garland. Imprints from hopping squirrels connected trees like strings of lights. One trail decoration was slightly different. Marked by a subtle change in the color of the snow, it was simply a one inch thick line across the path.


Curious, I knelt down and poked through the snow with my fingers. They found a hollow beneath the icy crust. Sliding my fingers under the crust, following the two-finger-wide line of gray, I peeled the crystalline roof off a long, narrow tunnel. In the frozen slush on the tunnel’s floor were tiny footprints in a diagonal walking pattern.


Was this the secret passageway of a tiny forest sprite or snow fairy? The hallway of snow would certainly protect its travelers from the bitter wind that reddened my cheeks.


No, not a fairy, but this tunnel belonged to a forest sprite in its own right – a shrew. We have six species of shrews in Wisconsin, and they are all tiny. Short legs, a pointed nose, slender body, and small eyes and ears help shrews function at the interface between soil particles and plant debris. Here, they use their acute sense of smell and even echolocation to find food. This habitat is rich with their favorite prey: insect larvae, ants, beetles, crickets, grasshoppers, spiders, centipedes, slugs, and snails.


Shrews have an extraordinarily fast metabolism and digest their food very rapidly, so they must feed voraciously night and day. A shrew can only last a few hours without food, and must eat more than its body weight in a day. One species of shrew, the short-tailed shrew, has developed venomous saliva that can stun larger animals such as mice, rabbits, and cats. This allows them access to larger meals.


The venom may also help protect the short-tailed shrew from its many predators: larger shrews, owls, hawks, snakes, frogs, and fish. Large mammals like foxes, weasels, and bobcats, may kill and eat shrews, but often leave them on the ground, presumably because of the species’ strong odor. Deb Malesevich, Museum Director, told me a story about her indoor/outdoor cat, OhOh, projectile vomiting a shrew across the living room as Deb dived to catch it in a wad of paper towels. What does that tell you about the palatability of shrews?


Palatable or not, most shrews die within the first year, if not the first two months of life. We found one of those casualties outside the Museum’s back door just the other day. Whether death came by starvation or a predator, the result was the same. I carefully measured the body, tail, and hind feet to help me identify it as a masked shrew, Sorex cinereus, the most widely distributed shrew in North America. It is in a different genus than the short-tailed shrew, and is not reported to have a venomous bite.


As I examined the rigid, furry corpse I was astonished by its diminutive size and weight. Measuring less than four inches from nose to tail, and weighing less than a penny, it is amazing that this critter can survive a Wisconsin winter at all!


At that size, staying warm can be tough. The subnivean layer, where snow meets earth, stays at a relatively constant 32 degrees. While this may not seem tropical to you, compared to a -10 degree wind chill topside, it is a major improvement. Deeper snow means more insulation from the skyward elements, so I bet shrews love snowier winters, just like skiers.


[Why do YOU love winter? Send me your reason(s), your first name, and age, and they will be posted on a website, coming soon! You can also look forward to a new exhibit coming to the Museum in February: “We LOVE Winter!” about local animals and their adaptations to snow and cold.]


Along the trail, tracks grew indistinct and the wind picked up as the gray skies grew darker. On this cold winter afternoon, I would not have minded a calm, cozy tunnel myself!


For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.


Find us on the web at to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot,

Life Under the Ice

Nets in hand, a line of Master Naturalist students ventured onto the dock. Snowflakes danced on the wind as a prelude to the big snowstorm yet to come. For now, the thin ice in the marina by Barker’s Island in Superior only held a layer of snow one flake thick. Dr. Joel Hoffman of the EPA had broken open a narrow channel in the ice parallel to the dock, and was about to help us discover a hidden world. 

Underneath the snow-free ice, he explained, sunlight penetrates enough that life continues as usual. But what is usual for a harbor connected to Lake Superior? Our nets were made of 150 micron mesh. One micron (or micrometer or ┬Ám) is a millionth of a meter. We sure were not trying to catch fish! A Northland College student sampled with one diamond-shaped net. This plankton net is designed to be let down to the bottom of the lake and drawn straight up. It provides a cross-section of the entire water column. John Kudlas, a steadfast Museum volunteer and educator, used the other net on a long handle to sample one layer of water with a horizontal sweep.

The particles in the bottom of the nets did not look particularly lively to our naked eyes. Most of the organisms that Joel expected us to find were only about 1-2 mm long. We brought them in out of the chill, rinsed the samples onto petri dishes, and put them under dissecting microscopes. 

The makeshift office of the brand-new Lake Superior National Estuarine Research Reserve (NERR) erupted with enthusiasm. “Wow! Cool! Oh my gosh, look at this! Joel, what’s this? Did you see that? Check out what I’ve got? Here’s a good one! Oh it just moved. You’ve gotta see this!”

Copepods, cladocera, and rotifers, oh my! Tiny aliens swam, spun, and ate before our eyes. Joel had drawn diagrams of what we might see on the board, and now they came alive.

Copepods were some of the most common critters in our samples. These tiny crustaceans live in the sea and in nearly every freshwater habitat (including the lake right outside your door!). Their teardrop-shaped bodies are covered by an exoskeleton so thin it is transparent, and are adorned by large antennae and a single red eye. Bristle-like setae do most of their sensing, and can differentiate patterns in the water flow around the body caused by approaching predators or prey. Some copepods have extremely fast escape responses when a predator is sensed, and can quickly jump a few millimeters.

Such small creatures do not need a circulatory system. One group, the Calanoid copepods, have a heart, but not blood vessels. Most lack gills and let oxygen absorb directly into their bodies. The copepod larval form is even simpler, consisting only of a head and a small tail, with no thorax or abdomen. The larvae must molt 5-6 times before emerging as a larvae with all the parts. After 5 more molts it reaches adulthood. This process can take anywhere from a week to a year, depending on the species, temperature, and food availability.

Some scientists say that copepods form the largest animal biomass on Earth. Since copepods use carbon to create their exoskeletons (discarding 10 or more exoskeletons over their lives), and release carbon into the ocean through respiration and scat, they are important to the global carbon cycle. The upper layers of the ocean are the world’s largest carbon sink, and can absorb 1/3 of human’s annual carbon emissions.

Several copepods ate their carbon-based lunch as awed students spied through the scopes. Their mouthparts swished the water to create currents that drew food toward their bristly setae. Large particles were individually caught by “fling and clap” movements where appendages grasped both the particle and a packet of water surrounding it, and removed the water by an inward squeeze.

All too soon, the students returned the samples to the lake. The snow fell harder. With less sunlight filtering through the ice and snow, life in the lakes will slow down a bit for the winter. Some critters enter resting stages, others just slow their metabolisms. As you look out over the frozen lakes, can you imagine tiny, translucent copepods living in their hidden world?


Even as I parked my car at the trailhead, my eyes were alert for tracks in the slushy snow. Although the parking lot itself was almost snow-free, little plops of slush marked where a dog and their person had walked through the snow, compacting it underneath, and pushing snow out to the sides of their soles. The denser snow of their tracks melted more slowly, and left a curious pattern of raised tracks on the damp pavement. Such small actions can make the difference between solid or liquid water at this time of year.

After examining the tracks, I walked up the leaf-strewn and snow-lined path toward the North Country Trail. I had never been to this section, just north of Lake Owen, but it is beautiful! Soon I noticed curious tracks in the deeper snow on the side of the trail. A five-pointed crown of toes topped an oblong footpad. The impressions of the hind feet were almost as big as my hand. In one spot, I could see the faint trough from the otter’s belly slide.

Farther along, a skinnier trough, only an inch or so wide, crossed the trail between a fallen log and the base of a big white pine. Tiny voles and shrews make these channels in the snow, often burrowing beneath the snow when it is deep enough. This time, their furry little backs may be have been exposed to the watchful eyes of a raptor. But luckily for the little mammal, there were no signs of blood.

At the base of another tree, a dead maple, lay the scattered chips from a frenzied woodworker. Smaller holes, just over an inch in diameter, accented a long vertical groove where the pileated woodpecker chiseled into the center of the tree. While you may blame the bird for the damage, it was only feeding on the carpenter ants that have already colonized the tree. Since the ants eat interior wood that is already dead and retired from transporting water and nutrients, a tree can survive for a long time while being hollowed out by ants and their predators.

Around another corner, I found a tree with a completely different injury – a huge white pine was twisted and splintered across the path. Here was an entirely different tracking medium. Many insects inscribed their stories in the woody scroll.

Most striking at first were the 8mm diameter exit holes of adult sawyer beetles. On a warm July day, an odd-looking creature emerged from the perfectly round hole. Aptly nicknamed the longhorned beetle, a male’s antennae can be twice the length of his body. Those antennae contain chemical receptors finely tuned to finding recently dead or stressed trees. Although it may just smell like pine to us, the beetle smells dinner and the potential for romance.

After adult sawyer beetles mate and lay eggs on dead tree (live trees would defend themselves by covering beetles in sticky, turpentine resins), the larvae burrow into the tree to feed on the phloem and cambium layers. This inner bark of the tree is responsible for sugar transport (including maple sap!) and growth, and provides more nutrients than the hollow dead tubes of the xylem (sapwood) that carry mostly water. Shallow, wiggling furrows, ending in small, dark holes, marked the beetles’ feeding progress on this fractured white pine.

In early fall, the sawyer beetle larvae begin to excavate clear through to the center of the trunk with a scraping, sawing sound. Just like the woodpecker, they leave behind a trail of splintery frass that is not ingested. Next summer, they will exit through much larger holes, the ones I noticed first.

Nearby, on a dead balsam fir, smaller bark beetles had inscribed their life stories. Deeper horizontal burrows carved by the adults were punctuated by tiny round chambers like a string of pearls. The female would have laid an egg where there now was a round chamber. After hatching, the larvae burrowed up a bit, toward the surface, and excavated much shallower channels at right angles to their mother. When mature, they all backtracked out the entrance hole made by the father.

The light faded as I turned back toward the trailhead. Hurrying along to beat the sunset, I noticed that the trail itself was in a depression that closely resembled the belly track of the otter, the trough of the shrew, the woodpecker’s lunch counter, and the beetle’s burrows. How many feet had carved this trough, and what are their life stories?

In many small ways, we each leave our mark on the world.

Feathered Feast


Thanksgiving dinner was a raucous affair. Thousands of guests dived in head first, gobbling up the delicate greens and crustaceans. Some preferred crisp white tubers, seeds and grains. Frog legs, fish, and escargot tempted the tastes of still others. New arrivals joining the feast from the far north appreciated the mild weather and plentiful food. Some guests took breaks from eating to nap in a quiet, out–of–the–way area, while others bathed noisily nearby.


You may think my family is a bit odd, but we were not alone. A couple dozen other birdwatchers with spotting scopes and binoculars had also stationed themselves at various overlooks along the Mississippi River on Thanksgiving Day. We chose the narrow, winding, graveled Red Oak Road just south of Lansing, Iowa, for our observation point. The road hugs a hillside above the railroad tracks, overlooking a marshy backwater of Old Man River.


Nearly half of North America’s bird species, and about 40 percent of its waterfowl, spend at least part of their lives in the Mississippi Flyway. It is a globally significant flyway and habitat for more than 325 species of birds. We spotted Tundra Swans, Canada Geese, Northern Shovelers, Northern Pintails, Hooded Mergansers, Canvasbacks, Green-winged Teal, Ring-necked Ducks, Buffleheads, Lesser Scaup, Wood Ducks, Mallards and more. They dove, dabbled, floated and napped in the early afternoon sun.


The Mississippi River’s watershed covers 41 percent of the continental U.S. as it stretches across the heart of the nation. Still, it is only one section of the longest migration route in the Western Hemisphere. The flyway continues north along the Mackenzie River in the Northwest Territories of Canada, finally reaching its northern terminus on the shore of the Arctic Ocean. While most birds only follow this route as far south as the Gulf of Mexico or Central America, some shorebirds fly all the way to Patagonia at the southern tip of South America.


Without warning, some unseen danger startled the feasting birds, and about half the dinner party took to the air, calling and honking wildly. The flash of sunlight on the Tundra Swans’ white feathers was breathtaking. From take-off en masse, the flock divided into long strings and V’s, self-organizing according to avian guidelines I can’t even imagine. Soon, smaller groups of a dozen or fewer circled back and made their splash landings in the backwaters. The supposed danger must have passed or never materialized.


Unfortunately, the coyote or eagle that may have startled the group might not be the biggest danger they face. Invasive species, pollution, flood control, droughts, land-use practices, and agricultural run-off all threaten the health of the river for both human and wildlife use. What will happen to this gorgeous feathered spectacle in the future?


For today, none of those threats was deterred the birds, and my family simply enjoyed the chance to stand in the sunshine and watch intercontinental travelers go about their amazing lives.


And did you feel it, in your heart, how it pertained to everything?

And have you too finally figured out what beauty is for?

And have you changed your life?

                        Mary Oliver, The Swan


For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.


Find us on the web at to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot,

On the Edge

This morning I drove toward the edge of the world. As I approached the end of the pavement, moment after moment, the world emerged from thick, white nothingness and revealed itself before me.

A bit dramatic, perhaps, for describing a foggy morning in late fall, but such was the mood of the light. The morning was part beauty, part eerie, and part mystery. Frosty fields and forests zoomed by on either side, and a pallid sun, somewhere above the world’s ceiling, found the strength to make them sparkle.

I’ve had the feeling, lately, that we are living on the edge of the seasons. Any moment now (I hope!) the puddles will freeze and stay frozen. The frosty grass will not darken and melt under the low-slung sun, and will instead disappear under thickening layers of snowflakes.

Water itself is living on the edge these days—the edge of phase transitions from gas, to liquid, to solid. Each of these transitions results from changes in temperature and the amount of energy. Heat is the energy of molecules in motion, and thus the phase of water is directly related to its temperature, an indicator of heat energy.

Our daily temperatures fluctuate from just below to just above the freezing point of water (which is the same as its melting point). Each night when Orion presides over icy stars, the temperature here on Earth drops. At the dew point, water molecules in the gaseous state slow down enough to condense into liquid water droplets, suspended in the air. Clouds of fog appear near the damp earth. The invisible gas becomes visible, but it conceals the solid world. Gas to liquid.

The same thing happened as my tea pot whistled cheerily, expelling hot water vapor that condensed into visible steam in the chilly kitchen. Taking my mug of tea, I went down to the lake where a fragile layer of ice hugged the shore. It is so thin that I can barely see the ice itself. Only the unnatural stillness on the surface, or a tap with my toe, betrays the ice’s presence. The lake is on the edge of something, too.

Most of the lake is now at about 39 degrees Fahrenheit, the temperature at which water reaches its maximum density. Under Orion’s watchful gaze, the surface water’s temperature will drop farther – and begin to float. This colder water will accumulate until it reaches the magical 32 degrees. Then molecules align, crystals form, and the lake receives its winter lid. Liquid to solid.

When the dew point is below the freezing point, water vapor transitions directly from gas to solid, in the form of frost on solid surfaces. High in the sky, where the only solid surfaces are grains of dust, the frost becomes flakes. Ice crystals form directly from water vapor in the air, using dust as condensation nuclei. A snowflake’s complex sixfold symmetry is guided by the chemical properties of water. As the incipient snowflake travels around a cloud, more ice crystals condense on its facets, and their growth is influenced by the temperature and humidity of the air. The best snowflakes grow at 5 degrees Fahrenheit inside dense, humid, winter clouds. Gas to Solid.

No snowflakes fall today. Blue sky is becoming visible as the fog bank lifts. Energy from the sun heats the air and it expands, increasing the amount of water it can hold. Water droplets suspended in the fog evaporate and become invisible again, revealing that my path leads not toward nothingness, but into a fantastic and almost magical world. Even more amazing is that, as I tell my students, “It’s like magic, but it’s actually chemistry.

An Old Friend

The dark road curved beneath my headlights, and then straightened into a long trough between the trees. An old friend lay resting there, just above the pointed tips of spruce and fir.

Orion has been my favorite winter constellation for many years. Sometimes subtitled “The Hunter,” it seems apt that Orion is lying on his side tonight, perhaps resting up for an early morning of deer hunting. Traditionally, of course, his quarry was more mythical—chasing the beautiful seven sisters of Pleiades, doing battle with Taurus the Bull, fighting a scorpion sent to tame his ego, or hunting the constellation Lepus the Hare.

In Australia and New Zealand, Orion appears upside down, and his distinctive belt and sword are imagined instead as a cooking pot. Perfect for the end of hunting season! Closer to home, some in the Ojibwa culture call this constellation Kabibona'kan, the Winter Maker, as its presence in the night sky heralds winter. Indeed, he can be seen from November to February each year. 

Of the four stars that form the rectangular shape of Orion’s body, Betelgeuse is my favorite. This reddish colored star forms Orion’s right shoulder, assuming the hunter is facing us. The red color is not an optical illusion, and it is not due to rusty iron, as is the color on Mars. Betelgeuse is a type of star called a red supergiant, and it gives off most of its light in the near-infrared wavelength, which we cannot see. It is at the opposite end of the spectrum from ultra-violet (UV) light, which is also invisible to humans. Only a small portion (13%) of Betelgeuse’s light is visible to our eyes.

Last week I discovered that if we could see UV light, we could tell male chickadees from females. This week I discovered that if we could see infrared light, Betelgeuse would be the brightest star in the sky. My narrow spectrum of human vision feels so limited, even forgetting that I have been nearsighted since 3rd grade! What is amazing is that we have built surrogate “eyes”—instruments that can “see” these wavelengths and translated them into beautiful images in the visible spectrum of colors.

With the help of these instruments, astrophysicists have seen hotspots and other features on the surface of Betelgeuse. One astronomer characterized Betelgeuse as “an enormous seething restless cauldron of belching plasma.”

Something that violent can hardly last very long. Indeed, Betelgeuse has already used up its supply of hydrogen for nuclear fusion. This means heavier elements are fusing together, and the star’s core is compressed into a hot, dense, ball, while other outer layers have expanded into the huge red mass we see today. Stars like this are rare—we only know of 200 in our Galaxy—because they do not live very long.

At about 10 million years old, Betelgeuse is thought to be near the end of its life. It will likely explode into a supernova within the next million years. When it does, it will be visible even in the day, brighter than the moon, and to an outside observer would outshine the entire Milky Way Galaxy.

While I admire the superlative nature of stars like Betelgeuse, I often think about how wonderful our own star is. Our Sun is just the right size, just the right distance, just the right age, and just the right brightness to make life on Earth possible.

This time of year, when gray clouds can hang low for many days in a row, a splash of sunlight on my face feels like wonderful gift. I am even grateful for when the Sun is not around. Crystalline stars and shimmering Northern Lights appear closer in these long winter nights. This time of year, Orion is really a perfect friend. He keeps me company on dark lonely drives, sparkles handsomely above my doorstep, and after hanging out with him, I can still get to bed early!

This world provides us with much to be thankful for. 

More Than Meets the Eye

Gray, gray, gray.  The gently rippled surface of the lake was gray in the early morning calm. Gray fog and gray clouds hung low over the gray trunks of the trees. Then a dark shape materialized out by the buoy. Shifting slightly, it revealed the white throat of a loon glowing through the gloom. As I watched, the loon dipped its face into the water, peering into the depths below. What it saw I cannot imagine, but its purposeful dive suggested fish by the rock pile. The loon’s sudden appearance and dive remind me that there is more to this silent gray lake than meets the eye.

Chick-a-dee-dee-dees in the balsam fir tree next to me reeled my mind’s eye back up from the depths of the lake. The flock from my bird feeders had followed me down to the lake for breakfast. I pulled a few sunflower seeds out of my pocket and extended my hand toward the birds.

With a whirr of wings, the first chickadee swooped from the fir tree and landed on my fingertips. Tiny toenails pricked my skin and one shiny black eye looked up at me from a cocked head. We examine each other tentatively.

I always feel a thrill when such a fluffy ball of wildness lands on me. I love the chance to see chickadees up close. Their backs are not pure gray, but tinged with a warm beige around the neck that spills over onto their sides. The edge between black cap and white cheeks is not smooth, but shows finely divided feathers. The base of the black throat patch where it grades into white belly feathers is even more irregular.

The frustrating part is that although this is my third winter feeding chickadees from my hand, I still can’t tell them apart. I am not even aided by markings that indicate male and female birds. So, I wonder, how do the chickadees know whom to romance in the spring?

We have long known that many birds can see ultraviolet light, but it took scientists a while to decide to test the UV reflectance of their feathers on a broad scale. In one study, scientists tested 139 species of birds that we believed to be “sexually monochromatic.” In other words, they tested birds that humans cannot identify as male or female by their colors. The study found that more than 90% of birds tested had UV reflecting feathers, and were “sexually dichromatic” from the avian perspective. Of course birds can tell each other apart!

My neighborhood chickadees are part of this pattern. If we could see in the UV spectrum, we would know that the males are brighter white and deeper black than females. Females prefer males with the sharpest contrast between white and black patches, which reinforces the trait in each generation. Males also have larger black patches, which we could potentially observe if we looked carefully. Interestingly, males with bigger black bibs tend to have more reproductive success.

With a quick dart forward to grab a seed, the chickadee on my hand whirred off to a branch in a flourish of gray. As other members of the flock flitted around in nearby trees, I marveled at my thoroughly human-centric view of the world, and tried to imagine life with another color in my vision. Just then, the loon surfaced through the mirrored surface of the lake. There is so much more to this world than what meets the eye, especially for humans.

Making Waves

Frosty sunshine peeked through the trees as more than a dozen adults pulled on their muck boots and backpacks. Crunching through dry and frozen plants down a slope into a bog, some ventured close to the edge of the floating mat surrounding the small pool of open water. Like monkeys jumping on a bed, they bounced up and down. Their exuberant energy transferred through the floating mat and made waves in the pool.


Full of smiles, questions, and hot coffee, this group of Master Naturalist students was thrilled to be on their first field trip. The group has been meeting one evening a week for several weeks, learning about Wisconsin geology, ecology, plants, animals, and much more. Each evening, an expert in the topic gives a lecture and takes questions. Then the organizers facilitate additional educational activities. This series of classes is one of two pilot courses for the brand-new Wisconsin Master Naturalist Program.


Students will end up with a Master Naturalist certification, similar to the Master Gardener program. Then they are required to pass on their knowledge by volunteering with parks, schools, non-profits, and other nature-oriented organizations.


In the opening lecture, Northland College Professor Tom Fitz gave an overview of Wisconsin geology. To set the stage for future lectures on ecology and plants, he presented the idea that the natural communities we see today are a result of three things: 1) geologic history, 2) current climate, and 3) recent disturbance.


Our bog exploration provided a great example of this theory. The slope we walked down into the bog was a jumble of sand, pebbles, and cobbles. This mess of sediment was deposited by the melting glacier more than 10,000 years ago. All that “stuff” was suspended in the ice. Some of it melted straight to the ground as “till,” and some of it was carried a little ways by streams of meltwater.


Where the bog is now, a chunk of ice was buried by the sand and gravel. When the ice melted, it left a depression with no inlet or outlet, called a “glacial kettle.” That’s the geologic history.


Our current temperate climate provides ample rainfall to fill the basin, and warm summers for plants to grow. For 10,000 years, plants have been growing inward from the edge of the basin. Delicate, drooping, grass-like plants begin the process. Woody leatherleaf shrubs anchor into the soil created by the grass, and reach out farther over the water. Sphagnum moss uses leatherleaf as scaffolding, with both plants engaged in a race toward the sun. As plants hanging over the water get heavier and sink, new plants grow on top of them, and reach ever-farther out into the pool.


The mat of dead and living vegetation extends all the way to the bottom of the basin throughout most of the bog. Only around the edge of the pool can you find a floating lattice of leatherleaf and sphagnum – floating, but able to support several bouncing adults!


Recent disturbance also makes its mark on the bog, where orange arrows indicate a snowmobile trail. The trail is visible even without snow, highlighted by lower topography, firmer ground, and a grassier selection of plants.


Thousands of people drive by this little bog on County Highway M east of Cable every year. Some may not notice it at all. Some may admire its beauty when the tamaracks turn gold, or when frost glistens on the plants at sunrise. After this field trip, one group of people -- with mud on their boots and a Master Naturalist certificate on their wall -- will see over 10,000 years of geologic history, current climate, and recent disturbance at work. They will surely make waves in their communities!


This Master Naturalist pilot course is being presented through a partnership between UW-Extension, Northland College, and the Cable Natural History Museum. Once the curriculum is finalized, we hope to hold more courses here in northwest Wisconsin. Contact Emily Stone ( for more information!


For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.



Find us on the web at to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot,


Saturday, November 3, 2012

Fairies and Fuzz-Butts

Do you believe in fairies? 

I inhaled a couple as I walked down to the lake on a warm, damp afternoon not long ago. Tiny, fluffy, bluish-white wisps floated in the fading sunlight. Like a swarm of gnats, only slower and more ethereal, the air was filled with fairies. I didn’t gain any magical powers when one got caught up my nose, but my curiosity was piqued. 

My first encounter with these tiny creatures was while scooping up a pot of water for supper in the Boundary Waters of northern Minnesota. My paddling partner, a more experienced USFS Wilderness Ranger, called the flying insects “fuzz-butts.” Who was I to argue? 

Years later on a hike I found whole colonies of similar beings, covered in white fuzz and clinging to alder branches like lint on your favorite pants. This flightless version had several ants tending them busily. Someone in the group produced a likely name: woolly alder aphids. 

Just like most aphids, woolly alder aphids suck plant juices from a host. The alder plant harvests sunlight, water, and air; the aphids harvest the alder’s sap; and then the ants harvest sugary honeydew secreted by the aphids. In return, ants provide the aphids some protection from predators. 

All the aphids in a colony are flightless female clones of their mother – until the days grow short. A single generation with females AND males occurs before winter, and the eggs from that generation will overwinter. Winged generations, like the flock of fairies I just saw, sometimes happen in response to food shortages. By flying to a new host before laying eggs, the parents give their offspring a fresh start. 

Both flighted and flightless aphids cover themselves in a white woolly covering made of wax, which makes an excellent defense against predation. Getting just a dab of it in my nose was enough to make me hold my breath when walking back through the flock of fairies! 

The feathery wax doesn’t seem to improve flying efficiency, though, and I caught several flying aphids on my fingers with quick sweeps through the air. The next challenge was getting the macro setting on my camera to focus on the tiny creatures. You can see my photos on the Museum’s Facebook page. They show much more detail that I could see with my naked eye! I love when photography can help us notice new things. 

Whether you believe in fairies or not, these tiny creatures sure add an air of mystery and beauty to any sunset by a lake. Let me know if you have seen them too! 

Tuesday, October 23, 2012

Green Islands

Leaves fell like glitter on the sun-showered path. These tiny yellow hearts of quaking aspen fluttered wildly as they descended, eventually ending in drifts built upon the wilted bodies of their companions. Placid raindrops beaded up on their slick surfaces, shining like jewels in the slanting rays of afternoon sun. A gentle sweetness wafted on the lukewarm breeze.

I do love fall.

And yet I already miss (just a little) the vibrancy of a buzzing summer day. Maybe if we could hold on to that green energy for just a little longer…

The golden leaves almost all had their own little hitchhiker hiding out between those slick, waterproof leaf-skins. My evidence? Bright green trapezoids of chlorophyll trapped between the first and second veins on one side of the leaves’ midribs. You may assume that the aspens are simply showing their support for the Packers. I have no evidence to discredit their status as cheeseheads, but the trees are not responsible for the variegated leaves.

A small, brown moth with white-fringed wings laid an egg on the leaf petiole (stem) back in July. By September, a translucent larva hatched and bored into the petiole, causing the stem to swell a bit into a small gall. Munching its way up inside the leaf under the cover of darkness, the larva interrupted the mechanisms the tree normally uses to draw chlorophyll out of the leaf during the waning days of autumn. The result is a “green island” in the yellow aspen leaves, and a forest carpet of Packers’ colors.

Such a tiny caterpillar would dry out in the summer heat, or if it tried to pupate high in the tree canopy. Instead, it takes advantage of pleasant fall weather, and then hitchhikes on the falling leaf down to the damp forest floor. Once there, it steals a few more bites of the green energy it preserved, and then pupates in relative safety and an agreeable microclimate. The soon-to-be-moth spends the winter in its cocoon, which is loosely woven to the surface of the now-brown leaf.
The receding snow and warming sun of May stimulate metamorphosis, and the new moth emerges from its winter sleep.

While apparently unstudied in the U.S., this drab moth and its tiny caterpillar have a Holarctic distribution. This means that they live across all the continents in the Northern Hemisphere. In fact, some of the information I have presented here was translated from Swedish and Dutch by the magic of the Google Translator! I can track this organism throughout the world by the universal language of scientific names. Ectoedemia argyropeza may not roll off your tongue, but scientists all over the planet use this one name to refer this particular species.

Whatever you call it, the vibrant green islands those moth larvae preserve are a lovely part of fall.

The Season when the Sun Shines Up from the Ground

This is the season when the sun shines up from the ground. The golden leaves of birch, maple, and aspen now carpet the forest floor, and reflect a special glow even on gray and rainy days when dense clouds hide the real sun. The sweet smell of damp, decaying leaves reminds us that they were sugar factories all summer long, making food out of thin air.

From the feel of chilly morning air pouring into your lungs, to the nostalgic smell of wood smoke, and the tinkle of skim ice breaking, fall is a season for the senses. Harsh and exciting calls from wild geese rise above leafless, bony gray twigs, and drift down to our ears with the first flakes of snow. Those fallen leaves crunch and rustle underfoot. At dawn, they sparkle with a rime of fairy-dust frost, then darken and molder slowly into a soggy wet mat as the sun softens the frost and starts the biological engines of decay chugging.

This is also the season for MuseumMobile programs, and several times a week I visit local schools for a full day of teaching in the classroom. I share a 30-45 minute nature lesson with each classroom of kindergarten-through-sixth graders. We talk about things like symbiosis, coal formation and mining, owl adaptations, food webs, tree parts, and spiders.

The kindergarten lesson is one of my favorites. Excitement stirs in the children as soon as I enter the room carry a large tub. “What’s in there?” They can’t wait to see! We talk briefly about exploring nature through our senses, and point to our eyes, ears, nose, mouth and tongue, reviewing just what those five senses are. Then I pass around a screen-covered sniffing-cup full of white cedar needles, and three cloth bags filled with various natural items from the Museum’s collection for the students to explore only with their sense of touch.

What fun to watch their eyes light up as they recognize a deer antler by the smooth feel of the bone! Little noses scrunch up to help eyes stay shut to keep from peeking. Sometimes excitement gets the best of someone and they blurt out the name of the object. They are just so proud to know something about nature! Five year olds here in our beautiful Northwoods know more about nature than the twelve-year-olds I used to teach from inner city San Francisco.

The grand finale of the kindergarten lesson is the snapping turtle shell. Bigger than my popcorn bowl, its shiny brown scales are fun for little fingers to rub and explore. We look at its backbone, and feel our own vertebrae, too. Then, everyone gets to be a turtle!  One by one I place the shell on the back of a huddled student, and announce “Bobby the Turtle!” and then “Susie the Turtle!” to a swarm of their giggling friends. As the “turtle” beams up at me with the joy of fun and natural connection lighting up their eyes, I think again: this is truly the season when the sun shines up from the ground.


For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.

Find us on the web at to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot,


Bright summer sunlight trickled through the thick canopy of trees and danced across the shallow stream. Two dozen little feet clad in their oldest shoes tramped through the water, too, somewhat less gracefully than the sun flecks. This was crick stomping at its best: a hot day, cool shade, refreshing water, and a sense of adventure.

I felt like a mother hen at the center of the flock as we moved our way upstream. Instead of pecking at grain, the chicks’ hands darted out to pick up this rock or that one. I was always glad when my campers got as excited about rocks as I did. The shallow, flashy, nature of the creek meant, on most days, several shallow channels braided themselves through wide gravel bars of interesting rocks. After big thunderstorms, I loved to watch as a torrent of brown water churned and frothed down the creek, revealing an alien landscape to explore as the floodwater receded.

On this particular crick stomp, we brought an honored guest with us. A NASA scientist named Owl (a camp name chosen because she liked the nighttime) was in the creek with us. She was part of a NASA outreach program involving girls, science, and education. She led us in activities like using recycled items to create creatures that could survive in each planet’s unique habitat, dissecting candy bars as if they were types of bedrock, and stargazing.

As an astrogeologist, Owl was particularly excited to accompany the girls on a crick stomp. They were soon distracted picking up rocks, but I stuck by Owl and let my curiosity show.

“Look here,” she said, pointing to a place on a gravel bar where flattish rocks were stacked up against each other like shingles. “When we see rocks like this, we know that water once flowed there.” “Obviously,” I thought in my teenage head, “this is a creek.” Owl continued: “By learning about rocks on earth, we can also learn more about rocks on other planets. If we see rounded rocks, or rocks stacked up like this on other planets, we know that there was once water flowing there also.” “Hmmm…” I thought, and tucked that bit of knowledge away in my brain.

As I went on to take geology courses in college, Owl’s words snuck back into my consciousness time and again. In class, we often talked about how you could read the story of ancient streams in the structure of the bedrock they had become. Knowing this gave me new eyes for observing flowing streams and the rocks they move.

This summer, I was barely aware of NASA’s latest project – the Mars rover “Curiosity,” until a friend (also a geology major) posted a news article on Facebook. The headline read: “NASA's Curiosity Finds Water Once Flowed On Mars.” The detailed photos showed rounded pebbles and streambed characteristics that could only have been formed by running water.

Scientists gathered enough data to estimate that the stream was between ankle and hip deep, and flowed about three feet per second. The characteristics of this Martian stream are preserved in a conglomerate, the type of rock formed when pebbles and sand become cemented together. You can find earthly conglomerate nearby at Copper Falls State Park.

Reading NASA’s report, I was immediately transported back to crick stomping with Owl in our shallow stream. “By learning about rocks on earth,” she had said, “we can also learn more about rocks on other planets…we can know that there was once water flowing there also.” Thanks to Owl, and a little Curiosity, the alien landscape of Mars seems a lot more familiar.

At the time Owl visited, finding evidence of surface water on Mars was a lofty goal for the future of space exploration. Now that the future is here, I wonder what the next generation of space exploration will look like, and if any of those crick-stomping girls will join the adventure.

Wednesday, October 3, 2012


Natural Connections


Emily Stone

Naturalist/Educator at the Cable Natural History Museum


As tree leaves stop gathering sunlight for food and prepare for the winter, it seems like that extra light is reflected back to our eyes in the brilliant colors of fall foliage. Green chlorophyll has faded away, and sugars it produced all summer are stored deep within the tree as starch.


In some trees, the fading chlorophyll reveals yellow and orange pigments. In other trees, red pigments are created in bright sunlight. While I appreciate the golden light that filters through an aspen stand in fall, it is the red leaves that make me really love autumn.


The staghorn sumacs around here are particularly colorful as their leaves morph through a rainbow of color, ending on crimson. They are also fast growing, short-lived, and tolerant of a wide variety of soil types and moisture levels. I am thrilled that sumacs like road ditches, because admiring their lively colors can improve almost any long drive. Sumacs are interesting beyond just their colors, too. Did you know that they are a member of the cashew family? This family also includes mangos, pistachios, and poison ivy!


Even while the leaves are still green, sumacs start to show red.  Large conical clusters of red-furred fruits sit at the ends of branches, giving a good show of color from June-September. Not every clump of sumac produces fruits, though. This observation troubled me off and on for years, until I realized two important parts of sumac’s biology: it is dioecious, and it reproduces vegetatively by rhizomes. Let me explain…

Dioecious (which means “two households” in Greek) indicates that each individual plant has reproductive units that are either only male or only female. Most flowers you encounter are monoecious, which means they have male and female parts in the same flower (“one household”). For sumac, this means that some trees are only male, and do not produce fruit. Ah!  That is one part of the equation.

Rhizomes are modified stems that creep underground and send out roots and shoots from their nodes. If you chop a rhizome up, a new plant could grow from each piece. Asparagus is a great example of a plant we propagate by its rhizome. In a clump of sumac, the rhizomes stay connected, and new plants grow outward from the center.  Since the oldest, tallest plants are in the center, clumps of sumac are often attractively dome-shaped.

As the sumac grows new shoots from its rhizome, it is actually producing clones of itself. If the parent plant is male, all the offspring will be male, too, and that clump will not produce fruit. Mystery solved!

To reward yourself for this new knowledge or for a bit of refreshment as you enjoy the fall foliage, why don’t you make a pitcher of sumac lemonade? Gather a half-dozen berry clusters and steep them in a pitcher of cold water for an hour or so. Strain out the seeds, hairs, and bugs through a cheesecloth. Add sugar or maple syrup to taste (remembering that these sweeteners were made by plants using sunlight), then chill and enjoy the rewards of a summer well-lived!


For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.

Find us on the web at to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot,


Sharpies at Hawk Ridge

Natural Connections

Sharpies at Hawk Ridge

Emily Stone

Naturalist/Educator at the Cable Natural History Museum


A blustery northwest wind cut right through two layers of wool as I stepped out of the car at Hawk Ridge in Duluth, MN. Binoculars, bird books, hot tea, and windbreakers in hand, my parents and I set up our watch with about fifty other birders and volunteers. Bright sunshine alternated with shadows cast by hurried gray clouds. Up on a wooden platform, several experts peered through spotting scopes, intently searching the sky. Their quarry: hawks.


Each fall, about 82,000 raptors pass over Hawk Ridge on their southern migration. Understandably reluctant to cross a large body of water, the birds funnel southwest along the shore of Lake Superior. The high, rocky outcrop of Hawk Ridge Nature Reserve makes a great viewing platform, and people from all over (like my parents from Iowa) come to watch the migration here.


Under some conditions, hawks will fly low over the ridge, zooming just above the heads of excited birders. Today, most of the raptors were tiny black specks in the distance, only visible by scanning the wild blue yonder with our binoculars.


Raptor biologists here have a special trick for getting close-up views of the hawks – bait. Using a technique a lot like fishing, researchers pull the string on a lure to make it look like an injured bird. When a raptor swoops down for an easy meal, it becomes tangled in one of a series of nets. Researchers carefully extricate it from the net, take a variety of measurements, and attach a numbered band to its leg. About three percent of birds banded here are recaptured. Based on the data collected from recapturing banded birds, sharp-shinned hawks migrating over Hawk Ridge generally head southeast to Illinois, and then southwest toward east Texas and Mexico, following the prevailing wind pattern.


Sometimes naturalists bring a recent captive down from the remote banding station so that folks on the overlook can get a better view. Moments after we arrived, two naturalists called everyone over to see a couple “sharpies” in hand. To prevent the hawks from hurting the humans or themselves, the naturalists held their wings, tail, and legs gently but firmly in the fist of one hand. The birds, both hatch-year females, looked quite calm.


Sharp-shinned hawks are the smallest hawks in North America, and have the biggest size difference between males and females. Females are up to one-third bigger than males, and this size difference means that they focus on different sizes of prey. Males tend to hunt smaller birds, such as sparrows, while females can concentrate on larger prey, like robins. This has two big advantages: males and females do not compete for the same food source, and chicks can get appropriately sized food as they grow.


During the first few weeks after hatching, the female sharp-shin broods the chicks while the male hunts and brings in small songbirds. He typically removes and eats the head before delivering the meal. As the chicks mature, the female joins in the hunting and brings larger prey for the hungry fledglings.


Sharp-shinned hawks are agile and acrobatic fliers, navigating dense woods at high speeds by using their long tail as a rudder. Short, rounded wings help them zip through tight spaces after small birds. During migration, they leave the dense forests of their northern nesting grounds and take to the open sky.


To help make the journey easier, these and other hawks will ride thermals, which are rising pockets of warmer air, formed by the uneven heating of the surface of the Earth. Thunderheads are visible thermals, where clouds of water droplets show just how high the warm air is climbing. When you see turkey vultures or other birds soaring in lazy circles without flapping, they are riding thermals. The energy in thermals comes from the Sun. You can learn more about them at our current exhibit: STAR POWER: Energy from the Sun.


For every mile a bird rises on this avian elevator, it can coast downwind seven miles without flapping. Still, sharp-shinned hawk’ migration from the top of this continent to the bottom takes strength, endurance, and stored energy. In order to be ready for the journey, these small hawks grow furiously—going from egg to adult size in just over 7 weeks.


The Hawk Ridge naturalists spent a few minute answering questions, and then asked someone to adopt the birds. For a small donation to support the research, the adopter’s name is linked with the band number of the bird, and if it is ever recaptured, the adopter will be notified. In addition, the adopter gets to release the bird. What a thrill!


In a flurry of feathers, the hawk left the adopter’s hand. It swooped below the cliff for a moment, giving us a spectacular “birds-eye view.” With a series of graceful circles, the sharpie gained altitude. Soon the little hawk was a mere speck in the sky, one of the many birds on an incredible journey, visible only through our scanning binoculars.


If you would like more information on the migration at Hawk Ridge, visit their website: You can also join Museum Naturalist, Katie Connolly on a Hawk Ridge field trip on October 18. Call 715-798-3890 for the details and to register.


For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.

Find us on the web at to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot,