Friday, April 19, 2019

Spires of Sand


“Trust your boots!” My friend Jamie and I encouraged each other as we scrambled up yet another near-vertical slope of sandstone. “Trails” as they call them in the Needles District of Canyonlands National Park in Southeast Utah, are often just cairn-marked exercises in disbelief. You want us to climb that? Should we really descend there? We have to jump what? (Don't worry, Mom, you already know I made it back unscathed!)


Here's Jamie navigating a pretty typical and non-scary rock formation on the trail.
And here's Jamie working her way down a ladder that was a little more tricky!
I just love this spot, but it takes two ladders to get to.
Nevertheless, our boots gripped securely onto the rippled sandstone slope and we found ourselves admiring another spectacular view. Clustered spires of red and white rock reached up into the brilliant blue sky. Where the spires had eroded away, a whimsically lumpy layer of white sand dunes-turned-bedrock clustered like mushrooms that only a nimble giant could hop along. Still lower, the pinkish soil of the canyon floor lay sprinkled with dusty green bushes and rich green Utah juniper trees.

The Needles District of Canyonlands National Park in Southwest Utah boasts an incredible geology on both big and small scales. Those spires are sometimes called "hoodoos." Photo by Emily Stone.

In the far distance, the deep red cliffs of Grand View Point in the Island in the Sky District of Canyonlands National Park dominated the horizon. When Jamie and I worked as Student Conservation Association interns here back in 2005, we discovered a good-natured rivalry between these two districts of the park. Although adjacent, they are divided by the Colorado River and separated by a long drive. “We have the best view!” the ISKY rangers would taunt. And indeed, from the precipice of Grand View Point, you can see for miles over the complex beauty of Utah’s canyon country. “That’s fine,” the Needles rangers would retort, “We ARE the view.”

Over 200 million years ago, this area sat on a battleground between swirling white sand dunes and muddy red streams. First one and then the other advanced their troops to deposit alternating layers. Eventually, everything was buried by even more sediment, and mineral cements hardened the sand into rock. Uplift from deep in the Earth caused fractures to form in an intersecting grid. Water and ice worked their erosive magic along those planes of weakness, and this pinnacled landscape emerged under the sculpting powers of geology.  
After Jamie and I caught our breath at the top of the slope, we meandered from cairn to cairn (cairns are small stacks of rocks often used to mark trails) across a potholed and gently undulating surface of old dunes. The view was never not spectacular, so we spent a fair amount of time gazing out over the hoodoos. You know me, though, and I couldn’t help but look down, too. Nestled into some of the bigger potholes and concave slopes were needles on a much smaller scale.

Sand dunes turned to rock provide an undulating surface where potholes can catch sediment and allow for the development of cryptobiotic soil crust. Photo by Emily Stone.

I just had to squat down for a closer look. The rugged surface of this pothole planet—for it did look kind of alien—was carved into miniature fins, spires and mesas. Dusty red sand was clearly at the base of everything, but it only peeked through the rainbow of black, white, orange, green, and even bluish skin. “Cryptobiotic crust,” we’d learned to call this strange microcosm during our long-ago intern training.

A delicate white wedgeleaf flower found refuge among the pinnacles and valleys of cryptobiotic soil crust in Southeast Utah. Photo by Emily Stone.
Cryptobiotic crust is sandy soil that had been glued together by tiny living things. Cyanobacteria move in first. While often referred to as blue-green algae because of their ability to photosynthesize, they are actually ancient bacteria who played a part in creating the oxygen-rich atmosphere we enjoy today.

Although dormant when dry, the sheaths surrounding cyanobacteria cells swell and produce little filaments as they absorb rainwater. Damp filaments weave among the soil particles and grab on. As the cyanobacteria dry out, the filaments secrete complex sugars which harden into glue. Over many years and many cycles of wetting and drying, a fragile crust develops. It prevents the sand from blowing away in dust clouds or becoming shifting fields of dunes. “Crusts are the glue holding this place together,” claims my well-worn Naturalist’s Guide to Canyon Country.

The crust’s diversity of both color and texture had brought me to my knees for a better view. Over the winter, frost heaves up the surface unevenly. Pedicels rise up to a few inches high and then plunge into sandy ravines. Against the dark surface veneer of organisms with UV-protective pigmentation, I saw rimes of white, dots of pink, caps of yellow, and cushions of emerald. The sugary glues and pore spaces between sand grains soak up water like a sponge, which improves the neighborhood for those colorful lichens, fungi, green algae, and mosses, whose rootlets also help hold the soil.

Colorful crust!

The cyanobacteria can also fix nitrogen directly out of the air, and their leakage constitutes fertilizer. Tiny plants use those nutrients where their seeds have sprouted in the shelter of the crust. Miniature white clusters of wedgeleaf flowers peppered the pinnacles like a fairy forest. Even this tiny world was not without catastrophe, though. One careless boot print on the edge of this pothole had crushed the fragile sheaths and set the crust development back by 25 to 250 years. If the impacts continue, this pothole might dry up completely and blow away, carrying the promise of life with it.

Straightening up again, my focus shifted back to the large-pinnacled landscape. Just as in the crust, dusty red sand is at the heart of it all, but the mineral cements of the rocks are much more durable than the cyanobacterial glue. Thousands of humans have walked from cairn to cairn—trusting their boots—with barely a whisper of impact. We joined them again, meandering among spectacular views both big and small.




Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books and will soon be available at your local independent bookstore, too.

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new Curiosity Center kids’ exhibit will open May 4.


Friday, April 12, 2019

Flyover Country

A cacophony of rattling cries filled the car as soon as my window slid down. While the engine noise faded, the chaos of sound crescendoed. Perhaps it isn’t surprising that sandhill cranes have such loud voices. At four feet tall, their extensive windpipes coil into their sternums. This amplifies the low, rich tones that can travel a mile or more across tundra, marsh, or field. Aldo Leopold wrote that they are “bugling the defeat of the retreating winter…”



Sound was only part of the experience, though. The soft gray bodies of cranes stretched as far across the stubbly cornfield as I could see. Farm equipment, irrigation sprinklers, and homesteads provided backdrops that faded in and out of the mist.

Every spring, over 500,000 sandhill cranes descend on the Platte River of central Nebraska. The agricultural landscape of the Great Plains may be derided by coastal humans as “flyover country,” but to the cranes, it is just the opposite. The shallow river and its gravel bars provide safety for nighttime roosting. Nearby farm fields hold feasts of waste grain, and surrounding wetlands provide additional food and habitat.

On their long migration from wintering grounds in northern Mexico, Texas, and New Mexico to their summer breeding habitat in the northern U.S., Canada, and even Siberia, sandhill cranes spend a very important month near the Platte River. Here they can put on an additional 10-20% of their bodyweight: fuel for the final leg of their journey.

As my friend Jamie and I poked our cameras out of the car windows, we were a little frustrated at how focused the birds were on eating. Heads down in the corn stubble, their fluffy gray rumps were cute, but not terribly photogenic. We could empathize, though. This crane-watching stop was just the halfway refueling point on our own, longer journey. The sunbathed slickrock of southeast Utah beckoned, but with evening descending, we also needed to find some dinner and a safe place to roost.

Feeding

Preening

The cranes find safety in numbers. In any group, at least a couple sentinels stood with their red-capped heads upright and alert for danger. I was surprised to notice that cranes near the roadsides turned and stalked inward as my little station wagon rolled by calmly. Cars often make pretty good blinds for birdwatching, and surely these birds were used to traffic on the country roads that dissect so much of their habitat. But while cranes are protected in Nebraska and Wisconsin, they are hunted in Minnesota, Kansas, South Dakota, and several other states. It’s good that they are skittish around humans.

Three sentinels

Dancing and Watching

At first I was frustrated that simply driving by would interrupt their feeding and cause them to move farther out of the range of my zoom. Once the cranes became agitated and stopped feeding, though, a few of them started dancing. Sometimes called “ambivalent behavior,” it’s a way to release nervous energy when the danger isn’t serious enough to cause flight.

Lifting great black-fingered wings, they flapped, bowed low to grab some scrap, and leaped straight up while tossing leaves, stalks, or corncobs into the air. Their pointed toes and slim legs emulated the grace of a ballet.






I’m sure a true courtship dance would be even more spectacular. The trumpeting unison calls of mated pairs would add to the intensity. The tango of two is essential to pair bonding, readying their hormones for mating, and even dissipating aggression between rivals. Parents dance with their colts to help them learn, and young cranes practice dancing for three years before they mate.

The sporadic dancing halted as a farmer on a four-wheeler sped off down a field. In great waves, wings opened and carried the birds aloft. They trumpeted and circled. The breadth of their reach, the urgency of their calls connected us to ancient rituals.

Cranes are often confused with great blue herons. But while herons fly with their neck in an S, cranes leave both legs and necks outstretched. Photo by Emily Stone.

Aldo Leopold wrote eloquently of the cranes in the “Marshland Elegy” chapter of A Sand County Almanac. “Our appreciation for the crane grows with the slow unraveling of earthly history…When we hear his call we hear no mere bird. We hear the trumpet in the orchestra of evolution. He is the symbol of our untamable past, of that incredible sweep of millennia…”

That isn’t mere hyperbole. Cranes are some of the oldest living birds. In Nebraska, a 15-million-year-old crane skeleton records their ancient stake on the territory. Over that time scale, the habitat has changed more than the bird. Several glaciers advanced and retreated; with the last one just creeping into the eastern edge of Nebraska. Perhaps, even back then, the dancing cranes meant spring, and their great flocks were “bugling the defeat of the retreating winter…”

As the four-wheeler disappeared around a corner, though, a silent group of the circling cranes began to descend.  Like a flock of Mary Poppins, they arched up their wings and calmly parachuted down with leggy landing gear outstretched. Sometimes, flyover country is the perfect place to land.


Coming in for a landing.

P.S. The cranes are back in Wisconsin, too! Have you also been hearing them fly over? 
This weekend is the Annual Midwest Crane Count. Find out more at:  https://www.cablemuseum.org/event/midwest-crane-count-4/




Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books and will soon be available at your local independent bookstore, too.

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new Curiosity Center kids’ exhibit will open May 4.

Friday, March 29, 2019

Red-winged Blackbirds

When springtime starts with persistent ice, gray skies, and tepid weather, it’s hard to get excited about the season. So I did what a lot of folks do: I went south. The drive down to Stevens Point, Wisconsin, was like traveling into the future. Bare fields stretched out languidly in the sunshine, migrating ducks paddles on puddles, and snow had retreated into the shadows. Back home, snow and ice still covered most surfaces and just a few new birds had arrived.

Perhaps the most exciting part of my drive was the end, when I stepped out onto the muddy parking area at the Central Wisconsin Environmental Station and heard the loud, rattling, trumpeting call of a sandhill crane. The thrill that went up my spine is quite different than the warm waves of happiness induced by a chickadee’s “hey sweetie” love song. And somewhere in the middle of those two is the joy of hearing the first ringing konk-la-ree call of a red-winged blackbird with its energetic trill at the end. All of those sounds echoed through the pines, and I couldn’t help but smile.



Red-winged blackbirds are true harbingers of spring. While they are year-round residents in much of their range, which stretches from the Yukon down to the Yucatan, the northern breeders must migrate far enough south to find crop stubble with waste grain and weed seeds not buried by snow. They gather in large flocks of as many as several million birds, and fly up to 50 miles each day from the roost to foraging grounds.

For red-winged blackbirds in the Great Lakes region, this generally means about a 700-mile trip. That’s not far in comparison to our “neotropical” migrants like hummingbirds, flycatchers, thrushes, and warblers who fly thousands of miles to overwinter in Central and South America. Those birds are nectar or insect specialists, and can’t eke out a winter survival on seeds alone.

One advantage that staying in the neighborhood gives red-winged blackbirds is that they have a better idea of how this particular spring is progressing, and can adjust their migration schedule based on weather. Neotropical migrants have no way to tell that spring is coming early in the north, so they stick to more stable cues—like day length—to decide when to migrate. Weather still affects their progress, since a winter storm or unfavorable winds can cause a delay, but their timing tends to be more consistent.

As a side note, robins can subsist on frozen fruits and berries that are held up above the snow. A number of them stick around each winter, farther north than you’d expect. Because you could also spot one weathering out a January blizzard in an orchard, they are not the best indicator that spring is on its way.

Red-winged blackbird males overwinter even closer to home than the females, because they have good reason to get back north as early as possible. The first male often gets the best territory, and it’s their gloom-piercing call that seals the deal. Belligerent males display in a “song spread” that includes fluffing up feathers, spreading their tail, raising their shoulders, and flashing their red epaulets, all while singing at the top of their lungs. We may appreciate this colorful performance, but it is not friendly, and it is not for us.

While the adventurous males who are leading the charge north are not on territories yet, they are already singing loudly—warming up for the big show. Drab, brown females will follow later, after insects begin to hatch. The ladies need a high-protein, high-calcium diet to prepare for egg laying, and have no reason to risk getting caught in a blizzard.

Once they arrive, females will choose a male’s territory, and set up a smaller territory within it. As many as 15 females might nest in a single male’s territory, but the average is five. Nests are built low to the ground, and are suspended among some upright stems of marsh plants. Females wind stringy plant material, wet leaves, and decayed wood into a bowl, and then line it with soft, dry grass.

My trip south was short, but I brought a little bit of spring home with me. As I stepped out of my car in the Museum’s parking lot, the first sound that greeted me was a ringing konk-la-ree. Maybe the warmth of that song will help melt our ice!


Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books and will soon be available at your local independent bookstore, too.

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new Curiosity Center kids’ exhibit will open May 4.


Worm Moon and Vanishing into Something Better

Something about spring sends me toward my shelf full of Mary Oliver books. In particular, I’ve been pulling out her older works, and ones I rarely open. My copy of Twelve Moons was purchased used, and the tape around its edges is yellowing and peeling back like the rind of ice on local lakes.



The first poem, “Sleeping in the Forest,” has long been one of my favorites. Its last line, “by morning I had vanished at least a dozen times into something better,” makes me think that by lying down in the moss I could eventually evaporate into the sky. Someday maybe I will.

When I arrived at the end of the book I didn’t recognize the final poem, “Worm Moon.” It had not previously spoken to me. But this week, when I read, “In March the earth remembers its own name. Everywhere the plates of the snow are cracking…And the name of every place is joyful,” I had to smile. Skimming along on snow-becoming-slush during my last ski of the season; watching green moss appear on the cut bank of my driveway; turning my face to the bright sun and the full moon…the Worm Moon has been joyful.

From my friends in southern Wisconsin, I know that the worms must be active there because the woodcocks are back. These little shorebirds don’t forage on the beach. They stick their long, sensitive bill into the wetland soil, open just the tip, and nab whatever writhes deep in the mud.

Birders practice their ninja skills when woodcocks get romantic. A male begins at dusk or dawn by “peenting” on his dancing ground. Then, without warning, he flies upward in a wide spiral and sideslips back down to his lek, making twittering sounds with his wings. The ninja skills come in as birders dart closer while he’s in the air, and hold their breath while he lands within arm’s reach. The lady woodcocks hides nearby and feigns indifference.

Whoever named the Worm Moon, though, must have lived farther south. Up here, not only are the worms still hiding beneath a foot of subsiding snow and the frost line, they aren’t native. Prior to plant nurseries transporting soil among roots, and fishermen dumping leftover bait on the shore, any native worms had been extirpated by the glaciers.

Various resources list other names for the moons of March and April: Snowcrust Moon, Sugarbushing Moon, Maple Sap Boiling Moon, and Broken Snowshoe Moon are a few. As my friends slog through their sugarbushes to tap trees, and fire up their evaporators, these names feel more accurate.

“The season of curiosity is everlasting and the hour for adventure never ends…” continues the poem. I agreed, so I put Yaktrax on my muck boots and moseyed down the driveway.

Meltwater covered the ice, and in one small puddle the sky lace of bare twigs lay reflected. Oak and maple leaves cupped the water as if they hoped to gain the lichens’ power to wake up from winter.



Moss was waking up in an emerald patch surrounded by snow. Resourceful, one-cell-thick leaves allow water to soak in directly to where it’s required. Moss doesn’t even have roots. They don’t need to suck resources out of the frozen ground. Their tiny rhizoids only serve to anchor them to the substrate. Moss does need a film of rain, or melting snow, to cover the outside of the leaf and act as a conduit for carbon dioxide to enter the leaf from the air.



On the nearby snowbank, a faded maple leaf caught the sun. Unlike the moss, no chloroplasts remained. Bacteria and fungi working all winter underneath the snow had taken all but its toughest cellulose. They enrich the soil. Soon, sugars made by that leaf will rise again through the maple’s trunk and feed the bursting buds. Spring is the season when all must be stripped bare in order for life to thrive again. The snow, the ice, the leaves: all vanishing into something better.






Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books and will soon be available at your local independent bookstore, too.


For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new exhibit: "Bee Amazed" is now open!

Friday, March 22, 2019

Tigers of Alaska

It’s doesn’t take much to entertain me. Last summer in Alaska, I had a few hours to fill before my Insects of Denali field course with Alaska Geographic would begin. Carrying just my camera, I sauntered off down a trail near the Denali National Park visitor center.


The vibrant yellow flowers of shrubby cinquefoil caught my eye first. Several blossoms had a single small fly basking near their center or walking stilt-like over the bristle of anthers.



Three willow leaves were sewn together in a small chamber. Tiny brown dots of frass (caterpillar scat) spilled out one end and identified it as a feeding hideout rather than a cocoon.



And then I came upon a hillside patch of bluebells. With tall, leafy stems and many clusters of delicate pink and purple bell-shaped flowers, it caught my eye right away. These were tall bluebells, or Mertensia paniculata. While they can be found as far east as Michigan, I think we typically see Virginia bluebells, or M. virginica in the Midwest. An easy way to tell the difference is flower shape: Virginia bluebells have a wide flower that constricts abruptly to a narrow nectar tube. The nectar tubes of tall bluebells are just a little smaller than the rest of the flower.



What also caught my eye about this patch of beauties is that they were being visited by a large tiger swallowtail butterfly. I’ve always loved these lovely yellow butterflies with black stripes, bits of orange and blue, and whimsical tails. Like the bluebells, they are close cousins to my friends back home.



My camera and I had a lovely time observing the butterfly dangle delicately from the flowers, nuzzle its head up into a bell, and then float airily on to the next plant. While this tiger must have been finding nectar to sip, it isn’t useful for transferring pollen. Part of the reason is that only the younger, tightly closed pink flowers contain the pollen, while the older, purple flowers provide nectar. Bees, who have the strength to pry open the pink flowers, are the only known pollinators. They are attracted by the sweet blue flowers, but then visit both shades of flowers on the plant.

Both the tall bush of bluebells with its broad, floppy leaves, and the wide, sunny wings of the butterfly struck me as being out of place in Alaska. When I think of northern plants, my mind jumps to the low, tough, waxy leaves of blueberry, lingonberry, and most other tundra plants. When I think of northern insects, I think of mosquitoes, black flies, and warm-furred bumble bees.

Not surprisingly, Canadian tiger swallowtails have an interesting suite of adaptations to help them survive in their namesake country and in Alaska.

It begins when they are eggs. Female tiger swallowtails lay their eggs on leaves on the south side of trees. This provides more warming sun exposure for the developing larvae. Temperature is important! As the temperature increases from 54 to 86 degrees Fahrenheit (due to normal changes in weather, or just a great location) the larvae can increase their growth rate by up to 500%. There is a catch, though. Larvae on birch trees won’t grow faster, even if it’s warm. Only the more nutritious leaves of aspen trees allow for such rapid growth. The butterflies must choose their host plants carefully, and hope that aspen are available.

Another counter-intuitive adaptation is that if a caterpillar survives a summer cold spell, it will then begin to grow faster. The longer and the colder it was, the faster it will subsequently grow. This is a tricky business. Summer is the most vulnerable time for these insects. When fall comes, the larvae store up cryoprotectants to help them avoid freezing, and then transform into pupae. Once properly hardened off and hidden away, the chrysalis can survive at least seven consecutive days at -2 degrees.

During the summer, though, caterpillars aren’t well-prepared for cold. One risk factor? Larvae with food in their guts freeze at warmer temperatures.

Overall, tiger swallowtails are in a hurry to complete their life cycle in a brief northern summer. The faster that a caterpillar can get to the safety of a cold-hardened chrysalis, the better. Those increased growth rates help, as well as the fact that females lay larger eggs, and the caterpillars pupate at smaller size than their southern cousins. This does mean that the adults are smaller, too, but that’s just the price they pay for making sure their offspring don’t freeze to death.



I was entertained by this pretty yellow butterfly on a warm day in Alaska, and I’m entertained now, too, as its memory helps me escape the gray days of mud season. May its bright wings bring some sunshine your way, too.

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books and will soon be available at your local independent bookstore, too.


For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new exhibit: "Bee Amazed" is now open!

Friday, March 15, 2019

Emily's New Book is HERE!

Stop by the Cable Natural History Museum or Redbery Books to pick up a copy in person. 

Or order it online here



Do you also love finding adventure and intrigue in strange places? Emily Stone’s second book transports you across the moat into a magical world where nature is better than fiction. Elfin skimmer dragonflies dart above the incredible community cupped inside a single leaf. A leaf miner grows up before your eyes. Lichens surrender in order to survive. By using science to tell stories, Emily wields a magic that makes the whole world feel more alive.


Praise for Natural Connections 2:

Emily Stone highlights nature that often gets overlooked. From describing the adaptations of star-nosed moles, to examining how species came to arrive on Isle Royale, Emily has the rare ability to translate complex science concepts into readable and enjoyable essays for everyone. Her talent as an educator and gift for storytelling is evident on every page, as she weaves personal tales of exploration and curiosity throughout each season. The accompanying sketches add a charming element to this wonderful book. I will be revisiting both of the Natural Connections titles year after year.

-- Ken Keffer is an author and naturalist. His most notable works include Ranger Rick: National Parks and The Kids' Outdoor Adventure Book, winner of a National Outdoor Book Award. 


I expect to enjoy this Natural Connections book as much as the first one.

– Larry Weber, award winning science teacher and author of Spiders of the North Woods.





Emily M. Stone is a naturalist by birth, training, profession, and passion. Her childhood spent as a “mud and water daughter” led to a degree in outdoor education from Northland College and a Field Naturalist Master’s from the University of Vermont. As the Naturalist/Education Director at the Cable Natural History Museum in Cable, Wisconsin, Emily writes a weekly “Natural Connections” column published in more than twenty local and regional newspapers. She has earned several Excellence in Craft awards from the Outdoor Writers Association of America. Her first book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses, was published in 2016.

Proceeds from this book benefit children’s nature education 
at the Cable Natural History Museum.

ISBN: 978-0-9972061-1-1
$18.96

The interconnectedness of nature is a topic that fascinates adults and children alike. To schedule an hour-long, illustrated presentation based on the Natural Connections book, contact Emily at emily@cablemuseum.org. This engaging talk is perfect for libraries, bookstores, lake associations, conferences, and other community groups!

Fifth Grade Beaver

“Are you going to dress someone up like an animal again?” asked an eager fifth grader at Drummond Elementary this week. I’d called on the student with his hand up because I was hoping that he’d answer the question I had just asked: “What do you remember learning on my first two visits to your classroom this year?”

Jane Weber, our MuseumMobile Educator, recently developed three new lessons for our fifth grade classroom visits. In the fall, students learned about white-tailed deer, and practiced deciphering a deer’s age by the teeth in cleaned jawbones. For our winter visit, we dressed two students up like fish, and compared the adaptations of prey fish (sharp spines, laterally compressed bodies, and eyes on the sides of their heads) with predator fish (sharp teeth, torpedo shaped bodies, and eyes on the front of their head).

Now, for our spring lesson, we were about to learn about beavers. Like all animals, beavers have an impressive suite of adaptations that help them survive in their habitat. As teachers, Jane and I have adapted to a 5th grader’s sense of humor, and designed the lesson around dressing a kid up like a beaver.

I started with the feet. Beavers’ hind feet are webbed, of course, to help propel them through the water. Oddly, they also have a split nail on their second toe, which acts like a comb for spreading oil throughout their fur and removing debris. That oil is very important to beavers as they swim underneath the ice all winter long. Without it, they would be wet and chilled to the bone. So, after fastening two giant foam webbed feet around my victim…er volunteer’s ankles, I also handed her a photo of an oil can.

Two brown gloves went on next. Beavers have surprisingly dexterous hands that they use to bring mud to their dam and lodge, to hold twigs while eating, and to dig out deeper channels for swimming.

The class roared with laughter when I pulled a fancy faux fur jacket out of my tub. These students have been growing up in our MuseumMobile program since they were in pre-K, and some of them remembered feeling the soft pelt of a beaver in their early years. One girl gazed off into the distance as she described the soft, warm underfur of her memory. Another piped right in to tell me about beavers’ longer, shinier guard hairs that help shed water.

Jane had sneakily sewn a strip of Velcro under the back hem of the jacket. To this, I affixed a giant, flat, brown beaver tail, which also got a laugh. I also pulled a real (dried) beaver tail out of my tub to show around the class. They’d also seen this in kindergarten, but beaver tails never get old. Of course one kid peered at the cut end and exclaimed in disgust. Beavers use their tails for fat storage, and the now desiccated fat isn’t exactly pretty. But it was useful when the beaver was alive. That fat fuels their metabolism during the long winter to help them stay warm.

The students easily came up with three more uses for a beaver’s tail: swimming rudder, warning signal, and a kick-stand to help them balance when cutting down trees. Their tails also help beavers dive quickly under the surface, and help them stay cool in the summer. One thing that a beaver tail isn’t useful for: patting mud onto their dam and lodge. Only cartoon beavers do that.

Before handing our beaver her Mardi Gras-style mask on a stick, I brought out a real beaver skull. This isn’t the first time these students have seen that exact skull. It’s neat to provide continuity through the years. In kindergarten they have their first introduction to beavers, admire the skull, and feel the stick that’s been de-barked by a beaver’s teeth. In second grade we bring out the beaver skull to illustrate how the teeth of an herbivore differ from that of a carnivore. In fourth grade, when we dissect owl pellets and find lots of little mouse skulls, I show the beaver skull as a bigger example of a rodent’s orange front teeth.

Today we look more closely at the skull, and talk about the iron that stains the teeth orange, giving them added strength. We also note that the eyes, ears, and nose of a beaver are all sitting right at the top of its head. Even while swimming with their body completely submerged, beavers can have all of their senses attuned to danger.

Before I hand our volunteer her mask, I ask the kids how many of them use goggles for swimming. Beavers have built in googles, I tell them, and of course we’re all jealous. I’ve never met a pair of goggles I like. But beavers have a third, clear eyelid, called a nictitating membrane. It protects their eyes from debris while they swim. I show the class a clear plastic lens covering the eyes of our beaver mask, then hand it over to our busy beaver.

The last prop is a pair of ear muffs. Water in your eyes isn’t the only issue. Beavers have valves in both their ears and nostrils to keep the water out while diving. Now we’re all seriously jealous, as we commiserate over how terrible it feels to get water up your nose or stuck in your ears while swimming. Beavers may look a little odd, but they have some sweet tricks up their fur.



Our completed beaver now spins slowly to show off her adaptations, and we applaud her cooperation before dismantling the costume.



Then I pass out bingo cards filled with pictures of animals. The dams that beavers build, and the ponds that fill in behind them, are incredibly valuable habitat for countless species. I start calling off animals that rely on beavers: songbirds, wood ducks, kingfishers, mink, dragonflies, great blue herons, deer, pileated woodpeckers, and water lilies. At this point, the entire class is on their edge of their seats, just needing one more square to win. Of course, I’m chuckling to myself, because I designed three different bingo cards that would all win at the same time. “Leopard frog!” I call, and the class erupts.

As I clean up my supplies and wrap up the class, I’m still chuckling to myself. “Bingo!” I think to myself. Jane did a great job designing a lesson to teach fifth graders about the amazing adaptations of beavers.

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, will be available on March 14! Preorder yours at http://www.cablemuseum.org/books/.


For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our exhibit: "Bee Amazed" is open through March!