Loon Behavior on Lake Jocassee

Layered gray clouds hung low above Lake Jocassee, South Carolina, for our second day of Common Loon research. Despite high winds and heavy rains in the evening forecast, the morning lake was calm enough to be a mirror.

A Common Loon resurfaces briefly before continuing a long stint of 2-minute dives. On Lake Jocassee, SC, researchers have found that solo loons forage in deep parts of the lake, presumably catching big fish near the bottom. Photo by Emily Stone.

Having explored the flooded stream gorges in the upper lake the previous day, it was our pontoon’s turn to observe loons in the lower lake. Brooks Wade, owner of Jocassee Wild Outdoor Education and our pontoon driver for the day, aimed us toward the twin towers and yellow booms marking the dam built by Duke Energy in 1968.

Gulls appreciate stunned fish from the dam as well, so hang out on the booms.

 Photo by Emily Stone.

When the turbines on the dam are in action, loons gather here for a feast of stunned fish. On this morning, all was quiet. Dr. Jay Mager, professor at Northern Ohio University, put a fresh data sheet on his clipboard, and started by recording the water temperature, air temperature, wind speed, weather, GPS coordinates, and water depth.

While Jay was doing that, we all scanned the half-dozen or so loons in the area, trying to select one with plumage that was distinctive from the rest of the group. Then the timer started, and at two-minute intervals for the next hour, we recorded the loon’s behavior and proximity to other loons. Our loon swam and rested placidly, likely digesting a big meal. This hour clearly wasn’t representative of loon behavior overall, which is why scientists are always trying to collect more data.

Dr. Jay Mager, scanning for loons! Photo by Emily Stone.

Motoring over to a narrow section of the lake, we sought out a new research subject. The loon we found had particularly poor fashion sense. On the top of their back were brownish-gray feathers with pale, scalloped edges. This pattern is thought to indicate a juvenile loon. Ringing their body just above the water line were black feathers with white speckles more similar to the adult loons we see up north. This combination, we surmised, might mean that this juvenile was molting into their adult plumage for the first time.

The combination of brownish-gray feathers with pale, scalloped edges, and black feathers with white speckles just above the water line, might mean that this juvenile Common Loon was molting into their adult plumage for the first time. Photo by Emily Stone.

When a young loon migrates south at the end of their first summer, they are expected to stay on the ocean for a few winters to gain strength without the conflicts that occur around nests up north. There are just a few freshwater lakes in the south where gray-brown juvenile loons have been spotted over the summer, and Jocassee is one of them.

While Jay took care of recording data, I offered to be in charge of the stopwatch. When recording time-activity-budgets for loons, you need two timepieces. Jay has an app on his phone that is set to beep at 2-minute intervals for an hour. At every beep, the binocular-wielding observers help the recorder mark down the behavior. Was the loon resting, locomoting, preening, foraging, or being aggressive? And was the loon within 25 body lengths of another loon? How many loons?

TAB Data sheet.

My job, with the stopwatch, was to time the loon’s dives. “Down!” everyone blurted when the loon dove. Then we’d stay vigilant, scanning the water in all directions around the pontoon boat until someone spotted the loon resurface. “Up!” marked the end of the dive, and I would tell Jay the time. While loons here have been recorded staying under for up to four minutes, two minutes was an average dive in this location, which the depth finder on the pontoon measured at about 80 feet. My stopwatch was kept busy as the loon dove almost continuously for the entire hour.

A solo loon making long dives in a deep part of the lake (apparently eating big fish near the bottom) fits the pattern that Jay has noticed consistently over the past decade. Loon behavior here seems to be bimodal. The other mode is that in shallow areas of the lake, rafts of a few to twenty loons hang out together and feed cooperatively on “bait balls” or big schools of little fish.

One of the main goals of this research is to compare how loons on the salt-free waters of Lake Jocassee spend their time, versus loons who spend their winter on the ocean. While loons have adapted to living in the ocean by revving up a salt-removal gland the instant they taste saltwater, that gland requires energy to maintain. The ocean can also be a deep, dark, murky place for a visual hunter. So far, researchers on the ocean have found that loons spend 55-67 percent of their time foraging. On Lake Jocassee, the average is 54 percent.

That one number doesn’t tell the full story, though, because solitary loons here spend 64 percent of their time foraging, while social loons only spend 40 percent of their time foraging. Does that mean social loons have more time to rest and preen, important tasks in preparation for migration? Or does that mean they spend their extra time using energy on social interaction?

Two common loons in different stages of molt swam near each other and preened. 

As our beloved loons face an uncertain future with warmer lakes and shifting habitats, it will only become more important for us to understand their needs across all four seasons. The work done here, on Lake Jocassee, will help ensure that our Northwoods loons return healthy and well-fed each spring.

Not quite ready to fly...but this loon will head north in a month or so! Photo by Emily Stone.

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

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Summer Calendar will open for registration on April 1! The Museum is closed for construction until May 1. Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

The Loons of Lake Jocassee

Loons bobbed on the early morning ripples as our pontoon boat sped across the open waters of Lake Jocassee, South Carolina. “First loon!” someone exclaimed gleefully, but otherwise we ignored them. At least for the moment.

A loon floats on the calm morning waters of Lake Jocassee, South Carolina, a deep reservoir with crystal clear water that provides winter habitat for over one hundred Common Loons. Photo by Emily Stone.

When Brooks Wade, our host and pontoon captain, crossed an imaginary line at the divide between the big, round lower lake and the narrow arms of the upper lake, he cut the engine. The sudden quiet gave Jay Mager a chance to explain our task. “We’re counting all the loons in our half of the lake,” he said. “The other pontoon will count the lower lake.” Brooks pointed out the imaginary center line of the upper lake, and we began puttering up the west side, counting all the loons between the center line and our nearest shore. We’d tally the east side on the way out.

Looking at a map of Lake Jocassee, it’s easy to tell that this was once a watershed of steep stream gorges cutting deep into the “Blue Wall” or the southern escarpment of the Blue Ridge Mountains. Eons of water erosion—not glaciers—carved deep wrinkles in the landscape.

The lower lake includes both the Lake Jocassee Basin and the Devil's Fork Region. The upper lake consists of Lower Toxaway, Upper Toxaway, and Horsepasture. 

The Blue Wall.

Then, in 1968, when Duke Energy began building the Oconee Nuclear Station, they dammed the confluence of four rivers to create a reliable source of cooling water for the plant. The 350-foot-deep-lake filled, and the atoms began splitting, in 1973. The plant is still providing electricity to one of the fastest growing states in the nation, and today, a network of dams in this watershed creates hydroelectric power, too.

The outstanding water quality of Lake Jocassee also provides excellent winter habitat for Common Loons. Brooks got a major case of loon love in February 2010, when he began his job as a campground host by walking down to the edge of the lake and hearing a loon wail. Although they were newly married and had just moved from Florida, he told his wife Kay that they were never leaving.

Scientists used to think that almost all of our Common Loons spend the winter on salt water. From across the northern lakes, loons migrate to both coasts and the gulf each fall to avoid ice-up. After starting a business giving pontoon tours, Brooks began to think that the number of loons he saw each winter on this freshwater lake was significant.

In 2016, Brooks searched out LoonWatch at Northland College online and sent then-coordinator Erica LeMoine photos of wintering loons on Lake Jocassee. She put him in touch with former Northland College professor Jim Paruk, who by then was working for the Biodiversity Research Institute in Maine. Within a matter of weeks, Jim flew in and partnered with Brooks to capture and band the first Lake Jocassee loon, which someone named Bob.

This is not Bob. This is a different loon who was banded on Lake Jocassee and the spotted in Minnesota over the summer! Banding loons has allowed scientists to learn a ton about loon movements and behavior. Long-term research on the behavior of individual loons has been essential in advancing our understanding of their lives and conservation needs. Photo by Emily Stone. 

The next year, Jim brought in his colleague, Jay Mager, an expert on loon vocalizations teaching at Ohio Northern University, and together with Earthwatch they hosted week-long loon research experiences for adult volunteers for three years. By then, Brooks and Kay had started their own non-profit outdoor education program, and they took over the organization of the “Jocassee Loon Camp,” with Jay Mager and Jim Paruk each leading a different week of research.

The first day of Jay’s week begins with a count of all the loons on Lake Jocassee, which is why I was now puttering through the upper lake on a pontoon boat with Jay, Brooks, and seven other “loonatics.” With eyes scanning and binoculars at the ready, we spotted solo loons fishing in the deep water, rafts of loons preening near shore, and gaggles of smaller waterfowl like horned grebes, too. Jay kept the tally on his data sheet, and we were free to be amazed by the loons.

Here, on their winter habitat, the loons are finishing up a “catastrophic molt” where they replace all of their feathers, including flight feathers, and are water-bound for the duration. As a result, the loons here can look pretty scruffy. Many of their heads are grayish brown, and their black checkerboard backs are uneven. Stray feathers stick out at funny angles, and discarded feathers float on the waves after strenuous bouts of preening each day.

Preening can sometimes look like a form of contortion art! We saw them reaching with their beak, rolling over, and making quite a splash with their wings. Photo by Emily Stone. 

This loon is sporting a stray feather that will soon fall out and be replaced by snazzy summer breeding plumage. Photo by Emily Stone. 

One particularly avid preener’s antics showed off red and yellow bands on his legs. This was Bob, the first loon banded here in 2016! He was back again to demonstrate that at least some loons return to the same winter habitat each year.

Bob sports a yellow and a red band on one leg, and always seems to return to the same part of the lake since 2016 when he was banded. Photo by Emily Stone.

The hours ticked off as we counted a dozen…two dozen…then eight dozen loons! We’d wound our way up and down every single narrow passage in the upper lake, admired cascading waterfalls, and enjoyed a calm winter day with ample sunshine. But the count of 97 loons just wasn’t enough for Amanda, one of the volunteers. “We’ve got to get to 100!” she insisted, and scanned the sun-dappled waters relentlessly as we approached that dividing line between the upper and lower lakes.

Loons AND Waterfalls! Photo by Emily Stone.

Wing flaps are a common part of the preening process. Photo by Emily Stone. 

“Ninety-eight!” she cried triumphantly, pointing through the sun glare. And then, “Ninety-nine!” someone else called as that loon’s companion was spotted. Our count ended there, but with the second pontoon boat’s count of 31 loons, we’d tallied about the average number of loons.

All eighteen of us loonatics headed to shore—wind-burned and happy—ready for the next day’s task: observing and recording loon behavior. I’ll tell you about that next week!

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

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum’s current exhibit “Anaamaagon: Under the Snow” is open through March 11. The Museum will be closed for construction March 12 through April 30. Our Winter Calendar is open for registration! Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

Winter Wind and Wildflowers with Lois Nestel

As the snow melts and I enter the melancholy often brought on by mud season, I find myself seeking comfort in the words of Lois Nestel, the founding naturalist, director, and curator of the Cable Natural History Museum. Lois was a talented, self-taught naturalist, artist, and taxidermist. Examples of her accomplishments populate every corner of our modern museum building. Her legacy is strong in the work that we do.

Lois Nestel, the founding naturalist, director, and curator of the Cable Natural History Museum.

I never met Lois, but every Friday I feel a particular kinship with her as I send my “Natural Connections” article off to the newspapers. Lois initiated the tradition of a weekly nature column provided by the Museum, and did so with a gentle, reverent, poetic style. Her column was titled “Wayside Wanderings,” and the articles were compiled into two small volumes in 1975.

One of my favorite authors, Sigurd Olson, provided the introduction to Lois’s first volume. In his characteristic style, Sigurd wrote: “With the eyes of a naturalist, artist, and poet, season by season she has recorded the miracles she found there, miracles that epitomize the truth that we are all part of nature; that because of our primeval background we hunger for simplicities of the past, the beauty of flowers, trees, and animals.”

As I walked into work this morning, I passed by the dried stalks of the Museum’s pollinator gardens. With any luck, young bees are sleeping soundly within the hollows of those stems. Lois wrote:

“Most people are aware of the beauty of summer flowers and often bemoan their passing as winter approaches. This need not be a cause for regret because, while much color may be lost, there continue—as seeds, pods, and capsules—many forms that rival the flowers in beauty and grace. Many of these seed containers last throughout the winter, serving as food for wildlife and pleasure for humans.

“There is a sculptured beauty in the pods of various milkweeds and wild iris, evening primrose, cockle, and [ghost] pipes. Delicate grace is exemplified in airy sprays of sweet cicely, papery clusters of wild hops, and feathery virgin’s bower (wild clematis) twining over bushes, and in the dried grasses and sedges, each with individual form and style.

“To enjoy these and many other beauties of winter there are few requirements; namely these: get outside, have open eyes to see and an open mind, receptive enough to appreciate what is seen.”

While that passage on the beauty of weeds in winter is quite cheerful, it’s even more of a comfort to me that Lois also experienced melancholy, as she wrote:

“When a whistling winter wind is sculpturing the snowy waysides, I am inclined to stay indoors and do my wandering in memories of younger days. Of all the elements, strong winter winds are what I like the least and yet, in retrospect, even these have brought their measure of satisfaction.

“Perhaps it is because houses are more tightly constructed that these days, I do not hear the wind in the same way as in my childhood. Then the winter wind seemed a living thing that shrieked and moaned around the corners and clawed at the windows. But that soulless wail was great to hear when curled, warm and comfortable, beneath the patchwork quilts.

“Now there seems a desolation and bitterness in the wind as though it mourns the sadness and injustice in the world. But the wind is not governed by political upheavals, poverty or crime. It is as it has always been. Only the listener, the endurer, has changed.

“Those days I shiver with the birds huddled in more sheltered spots. I start nervously at sudden, violent gusts, as do the animals. The wind was once my playmate; I could run with it and contend against it, but now it no longer is my friend. The loss is mine.”

Today, while the last of the snow shifts from melt to ice, the wind feels mournful to me, too. Skimming Lois’s writings, I sought a bit of sunshine to poke through the clouds. I’m not sure I believe it yet, but I’ll try to trust Lois’s wisdom.

“Nothing lasts forever...There is a new warmth in the sun and each day brings changes so that even the seeming setbacks of late winter storms cannot alter the fact that spring is in the air.”

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

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum’s current exhibit “Anaamaagon: Under the Snow” is open through March 11. The Museum will be closed for construction March 12 through April 30. Our Winter Calendar is open for registration! Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

Heaven in the Northwoods

Note from Emily Stone: I’m so excited that Heaven has joined our Museum team! In between teaching MuseumMobile programs in schools, organizing spring field trips, and leading Junior Naturalist Programs, Heaven will be guest writing for Natural Connections about once a month. I’m looking forward to following her journey of discovery in the Northwoods!

Heaven Walker, Educator/Naturalist at the Cable Natural History Museum, will be guest writing for Natural Connections about once a month. Photo by Emily Stone.

The wonders of nature have fascinated me from a young age. Now I strive to understand the intricate natural workings of each place I live or visit. Cable, Wisconsin, is my newest place of interest. As the new Educator/Naturalist at the Cable Natural History Museum, I will get to use my fascination with the environment to connect both myself and the public with Northwoods nature.

From the rolling hills of southern Iowa where I grew up, to the Black Hills of South Dakota, and the coasts of South Carolina where I’ve worked, I strive to know the ecosystem in which I live. What new trees and wildflowers can I learn? Where can I find a new natural community to explore? What new animals can I observe? How do the animals interact with their natural habitat, and how do the local people interact with them? I love being a student of the land, connecting with the organisms who live there, and discovering how they all come together.

Now, in the Northwoods, I am itching to get out and start exploring. Guidebooks and online resources are fantastic for supplying information, but to really get to know a place you need to immerse yourself in it. That is exactly what I plan to do here.

For example, through reading I learned that bogs are acidic because of the sphagnum moss that grows there. This acidity results in a unique assemblage of carnivorous plants, cotton grass, and stunted black spruce. I cannot wait to get out and see the sphagnum moss that carpets the floor and search for the bug-eating pitcher plants, sundew, and bladderworts.

I am most eager to get to know the native trees who inhabit the Northwoods. One way I have been introduced to the tree species here is by working on the upcoming exhibit “Becoming the Northwoods” for the Museum. The Northwoods are the transition zone between the boreal forests of the north, and the deciduous forests of the south. Here, conifers like balsam fir who are at the southern extent of their range, mix with deciduous species like sugar maples in their northern reaches. This gives the Northwoods a beautifully unique blend of trees.

In contrast, my southern Iowa childhood was full of deciduous trees, while the only conifers I grew up with were red cedars. I was excited to see all the pines as I moved to the Northwoods! Now I am eager to meet them all, and to understand their place within this community.

Though the abundance of new plants I have yet to discover is exciting, the thought of getting to occupy the same place as wolves and black bears is thrilling. In Iowa, European settlement and expansive agriculture have pushed many wildlife species out of the state. Pre-settlement, black bears and wolves both roamed the prairies and forests. However, it is highly unlikely black bears or wolves will ever inhabit Iowa again; there are not enough wild spaces.

But up in the Northwoods, the vast forested areas have allowed wolves and black bears to cohabit alongside people. I am eager to learn all the ins and outs of sharing their space. I would consider myself lucky to get to see them.

My life in the Northwoods will bring a new adventure at every turn, and present numerous opportunities to learn. I am excited to discover this wonderful place and everything it has to offer. From hiking trails to wildlife encounters and interesting ecosystems, I am eager to get outdoors and learn about my new home. Let’s just hope the mosquitos don’t carry me away!

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum’s current exhibit “Anaamaagon: Under the Snow” is open through March 11. The Museum will be closed for construction March 12 through April 30. Our Winter Calendar is open for registration! Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

Black-backed Woodpecker in the Bog

“It’s here.” My partner and I had barely stepped out of our car when another birder, perhaps getting a fresh camera battery from his car, confirmed the sighting we’d seen posted online. “Take the left fork on the boardwalk,” he added. And then, “You can follow me.”

We slung our much smaller cameras around our necks and prowled down the Bob Russell Memorial Boardwalk behind him into Winterberry Bog. This sweet little forest, trail, and parking lot is part of the Sax-Zim Bog Important Bird Area about an hour northwest of Duluth, Minn. Here, on about 300 square miles of public and private land, the clay soils of an old glacial lake plain hold water, and the cold, wet climate has perpetuated a thick layer of peat on top.

Bog species such as sedges, tamaracks, and black spruce give the landscape a scraggly look, and open areas provide good hunting grounds for rare species of owls. Aspen uplands, rivers, lakes, meadows, and farms join in the patchwork. According to the Friends of Sax-Zim Bog at saxzim.org, it’s a “’magic mix’ of habitats that boreal birds love.”

Although the tamarack trees along the boardwalk lacked the green needles that clothed their neighboring spruces, that was to be expected. Tamaracks, also known as the eastern larch, or Larix laricina, are a deciduous conifer. In an unusual combination, these trees have needle-like leaves and bear their seeds in cones like spruces and pines, but they lose their leaves in the fall like maples and grow them back each spring.

Signs of life did eventually appear, revealed by motion among the tree trunks. A few people dressed in bulky winter gear and peering through a spectrum of optical equipment from giant camera lenses to modest binoculars stood on the boardwalk. Everyone was focused low on the trunk of a tamarack tree only a few feet away.

I hardly needed to zoom in to see the bird’s black head, white face with black stripe, black-and-white barring on their flanks, and solid black back. Five years ago I’d seen an almost identical woodpecker in this same bog, but that one had a stripe of white down the middle of their back identifying them as a three-toed woodpecker. This was their cousin, a black-backed woodpecker.

I saw this three-toed woodpecker in the same bog in 2020. Photo by Emily Stone. 

Black-backed woodpeckers like this one have just three toes, while most woodpeckers have four. They grip tightly to bark while prying off flakes to get at beetle larvae underneath. Photo by Emily Stone.

Both species specialize in peeling flakes of bark off dead or dying trees to get at the plump, juicy larvae of wood-boring beetles. They often forage in burned areas, blowdowns, flood-damaged forests, and other places where insects have moved in. Here, the eastern larch beetle has provided them with a giant and long-lasting buffet.

This tamarack tree has been infested with eastern larch beetles. Black-backed woodpeckers are now prying off flakes of bark to get at the beetle larvae, leaving the snow beneath covered in litter. Photo by Emily Stone.

Eastern larch beetles are native to the United States, and have always produced small and short-lived outbreaks. Since 2000, though, Minnesota has seen 20 consecutive years of outbreaks, with more than 440,000 acres infested, and no end in sight. Climate change is implicated in the beetles’ surge.

Adult beetles emerge in spring, find a new tree to infest, burrow into the bark, mate, and lay eggs. The mother beetles go on to deposit one or two more clutches of eggs. In the past, these “sister broods” didn’t have time to fully develop before winter. Longer growing seasons now allow more beetles to reach maturity each year, and warmer weather results in less mortality for the overwintering larvae. It’s a perfect storm, and forest pathologists have not found a cure.

Flakes of bark rained down gently and scattered on the snow beneath the woodpecker’s perch in the dying tamarack. As I watched, the bird craned her neck to the side and wedged her beak under a loose piece of bark. A quick chipping motion soon freed the flake. This distinctive foraging style is characteristic of both black-backed woodpeckers and three-toed woodpeckers. They rarely excavate deep holes. When your lunch wiggles just under loose bark, there’s no need.

While many birds find food in Sax-Zim Bog, people come here to find the birds. This is a southern outpost for many beings typically found farther north. Protected areas like Winterberry Bog and a welcome center run by the Friends of Sax-Zim Bog have facilitated easy access to unusual species for a whole community of people interested in observing the interplay of life and death in nature. In the words of the helpful birder “It’s here!”

Author’s Note: Portions of this article are reprinted from 2020.

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

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum’s current exhibit “Anaamaagon: Under the Snow” is open through March 11. The Museum will be closed for construction March 12 through April 30. Our Winter Calendar is open for registration! Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

The Breeze of Balance

After I silenced the beep of my alarm clock, the sound I noticed next was the wind roaring through the forest and around the eaves. It was not the first howling wind of this winter. Sometimes it wears on me—the constant battle, the whipping hair, and the unceasing noise—but some days it is invigorating and refreshing. What do you love or hate about the wind?

Wind crashes waves into rocks and ice at the mouth of the Cascade River on the North Shore of Lake Superior. Photo by Emily Stone.

The wind can be a symbol of unity, freedom, eternity and balance. It is as true ecologically as it is metaphorically.

The first time I encountered wind as a symbol of unity, I was on the south shore of Lake Superior, at a wedding on a piney point. A stiff breeze whipped through the trees and blew out the unity candle. With great aplomb, the minister launched into a beautiful and extemporaneous sermon on the wind as a symbol of unity. As the air swirled around all the guests and the happy couple, we imagined how our breaths came from and returned to the one body of air that surrounds us and the entire globe.

In some cultures, wind is personified as a divine messenger who is able to manipulate unseen energy. Indeed, wind is the main way that our Earth attempts to equal out differences in temperature. Energy from the Sun warms the Earth and the air above it, but it does not heat everything evenly. Some objects heat up more easily than others, and some areas of the Earth receive more energy from the Sun. As warm air rises, cool air flows in to replace it.

The stronger the difference in temperature, the stronger the winds. Think of it this way: in the summer time, the temperature difference between northern Wisconsin and southern Florida is not that big. In the winter, however, that temperature difference can get quite large. In order for our atmosphere to remain in equilibrium, the winds must speed up. Wind is the Earth’s attempt to find a temperature balance.

Wind disperses more than just heat. When strong winds carry away soil, microbes in the soil can act like hitchhikers and go along for the ride. Nutrients and organisms lost from one region may be deposited across the globe. The organisms may colonize otherwise inaccessible regions. The nutrients being blown around the globe may help forested areas obtain trace amounts of minerals. Some organisms in particular get a significant amount of nutrients from dust on the wind. Lichens and epiphytes (“air plants”) are two examples.

Insects also use the wind for long-distance travel. Just how high can they fly? In the book Insectopedia, Hugh Raffles wrote that researchers calculated that “on any given day, the air column rising 50-15,000 feet above one square mile of Louisiana countryside contained an average of 25 million insects.” At the upper limit, 15,000 feet, there was a ballooning spider who used his silk as a kite. Butterflies, dragonflies, gnats, water striders, leaf bugs, booklice, and katydids have been sighted hundreds of miles out on the open ocean, and aphids have been found on ice floes. Some wingless insects (and plankton!) are plucked from their earthly tethers by a sharp gust of wind, but very few are completely passive travelers.

Wind also helps lakes balance their nutrients and chemicals throughout various layers during fall and spring turnover. During fall turnover, when the surface water cools to about the same temperature as the lower water, the wind can mix the water masses together and even out the temperature and oxygen levels. A similar process occurs during spring turnover after ice-out, as colder surface waters warm to the temperature of bottom waters and the lake mixes. Water from the lake bottom brings nutrients up with it.

While Nature’s howling winds have their purpose, I would still prefer a gentle breeze. Liu Chi, a scholar in the Yuan and the Ming Dynasties, wrote about the wind in a pine grove. “Listening to it can relieve anxiety and humiliation, wash away confusion and impurity, expand the spirit and lighten the heart, make one feel peaceful and contemplative, cause one to wander free and easy through the skies and travel along with the force of Creation.”

With every breath, we invite the universe in. As the winter winds swirl around you, take a peaceful and contemplative moment to appreciate the wind’s role in encouraging balance and unity in our sometimes stormy world.

Author’s Note: A version of this article was originally published in 2013.

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

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum’s current exhibit “Anaamaagon: Under the Snow” is open through March 11. The Museum will be closed for construction March 12 through April 30. Our Winter Calendar is open for registration! Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

Frost Cracks

Fresh snow highlighted every twig, and more flakes floated down as we hiked through the Rainbow Lakes Wilderness Area on the North Country Trail (NCT). This intrepid group of women calls themselves the NCT Navigators, and they meet almost every Monday (when the mosquitoes aren’t out) to hike a section of trail. Most of them have completed the NCT’s 100-mile challenge. Most of them are retired, too, and I count myself lucky to fit in a hike with them even a few times a year.

Today the fresh snow was making the ski trails slow, and I was looking for inspiration, so I gave my friends an assignment: find me something to write about! Well, this artistic group had already gotten in the habit of noticing patterns in nature, and it wasn’t long before someone keyed in on an adorably squiqqly line snaking up the length of a tree.

A frost crack! Of course. What a perfect topic for a winter day. Long ago I learned that these cracks burst open with a noise like a rifle shot as a sunny day plunges into a frigid night. I couldn’t remember, though: was it the contraction of cooling wood, or the expansion of ice that caused the trunk to split? Both make sense. I pondered this as we hiked along, and also tried to spot more cracks throughout the forest. It wasn’t hard. While not on every tree, I could see a long, vertical welt from just about any point on the trail. Quite a few of the cracks had their upper terminus at a scar where a branch had fallen off, or some other blemish on the tree.

Back at the office, I sought a more complete explanation. My initial research was frustrating, though, since the sources all gave multiple explanations of frost cracks. Yes, it seems to involve the low-angled winter sun shining heavily on the southwest side of a tree. The bark and inner wood both warm up and expand. When the sun sets and the temperature drops, the outer bark contracts more quickly than the inner wood, and suddenly becomes too small a sheath for its core. The bark and first layer of wood split.

Another part of the explanation is that the heat causes the tree’s cells to break dormancy. Dead cells, which compose most of the wood, just freeze, but trees winterize their living cells in a few ways. Cell membranes become more flexible, which allows water to migrate out of the cells and into the intercellular spaces where it can freeze without harm. Trees also fill their cells with sugar in order to lower the freezing point of their remaining liquid. And, like magic, the syrup inside the cells supercools to a glass-like phase where it is so viscous that it appears to be solid, while not forming sharp crystals. In a sun-warmed tree, water may begin to move into places it shouldn’t. As the tree re-freezes, water shifts around and freezes quickly and unevenly, causing stress on the wood and opening the crack.

A few sources mentioned that frost cracks are often associated with previous damage to the tree, but the process didn’t fully make sense until I read an interview with a plant pathologist in Northern Woodlands magazine. Walter Shortler and his mentor, Alex Shigo, did a sort of forensic pathology for trees. They used a chainsaw to slice up thousands of logs to get to the bottom—or the top—of the frost crack issue.

The result? Shigo found that “All radial shakes [cracks along the radius of the tree] were associated with wounds, branch stubs, or basal sprout stubs, and with ring shakes [cracks that follow tree rings] at some point in the trunk.” Almost anything can create an area of weakness: fire, damage during logging operations, poor pruning techniques by humans, gnawing rodents, rubbing deer, root rot, basal sprouts, or branch stubs that didn’t heal. Trees that are damaged when young seem to be much more prone to later frost cracking than older trees that become damaged.

In any case, damage to the bark and underlying sapwood provides an entry for decay. Bacteria and fungi move in, and as they decompose the wood it absorbs extra moisture. The defective wood doesn’t expand and contract as well as healthy wood, and rapid freezing finally bursts open a significant crack. Repeated freeze-thaw cycles, coupled with stress from wind, can enlarge a crack, even as the tree tries to heal it.

So, a combination of all the forces I read about likely play a role in opening and widening cracks, but none of them alone would do the job without a prior injury. This all made sense to me, especially in light of my observation that many frost cracks we saw topped out at an old branch scar.

The tree will try to heal the wound, and the growth of new wood around the crack is sometimes called a frost rib. Indeed, we admired the raised scar that highlighted our squiggly crack.

Foresters, of course, are concerned with reducing damage to young trees so that frost cracks can’t gain a foothold in what could have been valuable timber. Naturalists might appreciate a different perspective. A little ways down the trail we spotted another tree with a convoluted scar. Nestled inside were two brown acorns. I suspect that naturally occurring frost cracks may provide valuable habitat for critters in their cavities and decay. In the words of Leonard Cohen, “There is a crack in everything. That's how the light gets in.”

Author’s Note: This article was originally published in January 2018.

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

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum is open with our brand-new exhibit: “Anaamaagon: Under the Snow.” Our Winter Calendar is open for registration! Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.