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!

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!

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

www.cablemuseum.org

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!

Seriously Fluffy Birds of Sax-Zim Bog

The thermometer on my car read -18 degrees Fahrenheit as I turned off the highway onto a snow covered road northwest of Duluth. A leaden sky didn’t offer any additional warmth. My parents and I were warm, though, wrapped up like onions in our many winter layers with the car heater blasting. We were looking forward to a full day of birding in Sax-Zim Bog. This 300-square mile mix of aspen uplands, rivers, lakes, meadows, dead-ending back roads and farms has become famous for its ability to attract and support many species of birds who usually remain farther north.

Our first destination was a windswept field with a gravel road bisecting it and string of utility poles lining the road. Anemic gray light made the scene look barren from afar, but soon a white shape materialized on the top of a particular pole. I pulled up beside it, rolled my window partway down, and turned on my camera. The shape shifted, rotated, and two dark eyes came into view.

Even though snowy owls sport thick feathers all the way down their legs, this one still chose to hunker down against the cold. Photo by Emily Stone.

Snowy owls can be territorial even in their winter feeding areas, and while there aren’t many other owls around to challenge him, this guy (male, as indicated by his very white feathers) seems to have staked out his claim. That’s a boon for birders who, like my parents from Iowa, drive great distances to see his species in the bog.

The frigid morning, complete with a stiff breeze left over from recent severe weather, didn’t seem to faze the owl. Why should it? Most of his relatives are surviving just fine up above the Arctic Circle. Food and space are more limiting than cold when you have thick feathers all the way to your toes. That substantial winter coat contributes to the snowy owl’s status as the heaviest owl in North America, weighing four pounds.

The open car window soon let in enough cold air to get uncomfortable, so we blasted the heater and drove up toward the Welcome Center run by the Friends of Sax-Zim Bog. Bright sunshine greeted us, as well as a cluster of bird feeders that were just wild with activity.

The stripy little birds with red smudges on their foreheads looked nothing like the snowy owl, but these common redpolls are no less birds of the north than he is. They breed all around the top of the globe, in a circle that borders the Arctic Ocean, and their global population numbers in the tens of millions. They must be doing something right.

Common redpolls add 31 percent more feathers for the winter, and then they also fluff out their feathers and tuck up their toes to stay warm on frigid days. Photo by Emily Stone.

Just like the snowy owl, these little birds have a thick coat of feathers. Redpolls add 31 percent more feathers for the winter. That’s a big increase for a bird that only weighs half an ounce to begin with. Back in January, when Prof. Sheldon Cooper from UW Oshkosh lectured our Winter Ecology participants about the Winter Ecology of Birds, he compared small birds adding feathers to putting a toddler in a snowsuit. A big critter, like a snowy owl or an adult human, can still move pretty well, even if you add some puffy layers. The smaller the critter, though, the more those layers can impede movement.

Redpolls do have one advantage over owls, though, because they can fit into sheltered spaces—snow tunnels for redpolls and tree cavities for most other small birds—that protect them from wind chill even better than feathers could.

Pine siskins put on more fat than many other little birds. They also fluff out their feathers and tuck up their toes to stay warm on frigid days. Photo by Emily Stone.

Just like adding feathers, adding fat has its pros and cons for small birds. Getting too fat can make it harder and more energetically costly to fly, and reduce their ability to escape predators. Chickadees may only achieve 10% body fat, and 12% better feather insulation even in the winter. Pine siskins, though, put on 50% more fat than redpolls do. Little birds don’t store fat in an insulating layer of blubber like penguins and whales; they accumulate stores of brown fat around their wishbone and abdomen as a ready source of fuel for their metabolisms. Birds can also store fuel outside of their bodies. One reason those chickadees don’t need to store fat is that they store food—in up to 2,000 little caches.

Black-capped chickadees don’t put on much extra winter fat; instead they store fuel outside their bodies in the form of food caches. Photo by Emily Stone.

What they do with that fuel is also important. Many birds shiver to stay warm. It’s effective, as long as they have plenty of fat to burn. They can also go about their business as usual. One study found that chickadees’ feathers can capture the heat generated by hopping around to eat. Forage more, shiver less, and you end up warm, with the additional benefit of a belly full of food.

Prof. Cooper’s lecture came back to me as we watched redpolls, siskins, and chickadees hop around the Welcome Center’s feeders. As I photographed a fluffed up siskin perched above the feeder with just its toes exposed, I thought back to a slide Cooper presented to us about “heat conserving postures." The diagram showed a little bird in warm weather standing normally with its legs and feet exposed. With each successive decrease in temperature, the bird squatted lower and surrounded more of its legs and feet with fluffy feathers. Despite his feathered legs, the snowy owl displayed a similar toe-hiding posture.

From inside my warm car, the sight of all these little puffballs made me chuckle. Once the frigid air hit my face, though, I was reminded that fluff is rather serious stuff to a bird in winter.

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!

Fur Bearing Insects of Denali

The only things fluttering around the Museum’s pollinator garden recently are snowflakes. Dried stalks of beebalm remind me of how vibrant that corner of our yard becomes by midsummer. Currently, the flowers are topped by little puffs of snow instead of fragrant purple petals and buzzing bees. Inside the Museum, though, we’re planning an exhibit all about pollinators. Even while traipsing all over Alaska last summer, I was thinking about pollinators.

Beebalm in the pollinator garden. Photo by Emily Stone.

And that’s how I ended up in a yurt, in Denali National Park’s Teklanika River Campground, at Mile 29.1 on the park road, listening to a presentation about “Fur Bearing Insects of Denali.” The instructor, Jessica Rykken, is Denali National Park’s official entomologist—charged with surveying, collecting, and archiving insects in the park. Denali’s 17 species of bumble bees represent one-third of all the bumble bee diversity in North America, and they are charmingly furry.

The dense hairs covering a bumble bee’s body help it to retain heat and stay active at cooler temperatures. Photo by Emily Stone.

The fur is for more than just looking cute, though, as Jessica explained. Just like my favorite wool sweater, the thick coat of hairs on a bumble bee provides insulation and allows them to be active at colder temperatures. Their relatively large body size makes it easier for bumble bees to retain heat as well. Using these adaptations, and by shivering their large flight muscles, bees can raise their body temperatures 60 degrees Fahrenheit above the air temperature! “I dress in a wool hat and full rain suit to go collecting bees!” commented Jessica.

She wasn’t joking. Outside the yurt, the picnic table sported a light glaze of frost, even in late June. The small group of naturalists taking this Alaska Geographic Field Course wore rain jackets, puffy coats, down vests, hats, gloves, and mittens. Hiking uphill to some of Jessica’s study sites helped us warm up briefly, but intermittent sunshine and drizzle had us adjusting layers frequently. We still found insects!

With warm clothes and snow in the background, students in Alaska Geographic’s Insects of Denali Field Course endured the same summer weather that bumbles must brave! Photo by Emily Stone.

Staying warm in the summer is one thing, but bees need to survive harsh winters in Denali, too. New bumble bee queens mature in late summer, mate with a male drone bee, excavate a small hole in the ground to hibernate in, and produce anti-freeze to keep from freezing as winter descends. Queens who survive the winter emerge in early spring and begin the process of starting a new colony.

Bumble bees need both nectar and pollen to fuel themselves and feed their colony. They’re able to forage on a wide variety of flowers, which helps make sure that there’s always a snack blooming nearby. While you might expect that only a few types of flowers can survive in the harsh environment of tundra, these low-growing plants that carpet the mountainsides and arctic slopes are the most diverse habitat in the state. As glaciers came and went across the continent, tundra habitat was always present somewhere in Alaska, and tundra flowers didn’t have to complete a long migration to recolonize places scraped clean by sheets of ice.

In such a cold environment, even flowers need ways to stay warm. The bowl-shaped blossoms of Arctic poppies and many other species are essentially solar collectors, and they can warm up quite nicely on a sunny day. Some flowers even track the path of the sun. A warm blossom can have many benefits. The heat will enhance evaporation of floral scents, which attracts some pollinators. A cold pollinator who drinks warm nectar gets a double energy bonus; similar to how hot chocolate warms us from the inside out.

The tiny flowers of Alp Lily turns to catch some warm sunshine. Flowers who capture added warmth from the sun can speed up the development of their fruits and seeds in the short Arctic summer. Photo by Emily Stone

I like to imagine a cold bee curling up inside a warm blossom for a nap, but one study found that the ground is an even better place for insects to bask. My classmates and I experienced that firsthand. We started by kneeling to look at an insect, and then slowly lowering ourselves down out of the wind onto the cushioned surface of the mountainside into a warmer microhabitat.

In reality, the ability of a flower to warm up may benefit the flower more directly than by attracting pollinators. Although flowers don’t need to warm up flight muscles in order to move, they develop faster at higher temperatures. Added warmth can help the pollen to germinate, help the pollen tube to grow as it searches out the ovule for fertilization, and help that ovule to develop into a fruit and seeds. All of those processes need to happen quickly, before the short Arctic summer descends back in to winter.

It seems like everyone and everything in Alaska shares that same overwhelming desire to pack as much into summer as humanly (or naturally) possible. Our insect class made use of long, midsummer days by collecting bugs until 10:00 p.m. Bumble bees dress in wool to go foraging. Tundra flowers make seeds while the sun shines. And I zoomed around with my camera and notebook, storing up memories to fuel my learning in the long winter ahead.

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, will be available in March! Listen to the podcast at www.cablemusum.org!

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!