A Summer of Loon Discovery

The pontoon bobbed in the water as I stepped onto the deck, clutching binoculars and trying to contain my excitement. Since moving to the Northwoods in the middle of winter, I had been waiting for the chance to see a loon, and my chance finally arrived in late May. The sunlight danced across the water as our boat left the dock, and we began our search. It wasn't long before we spotted the silhouette of a loon off in the distance, and headed for a closer look.

This loon was one of the most regal beings I had ever seen. They swam through the water with quick ease, head held high, only occasionally paying us a bit of attention. It was as if they knew they had our full attention, and as a result flaunted with a casual indifference as they floated around the boat. Their black-and-white spotted back glimmered right along with the sun reflecting off the water, highlighting their natural camouflage. We watched them preen their pristine feathers for a while, before they dove below the surface and left us behind.

An impressive loon swimming near our boat. Photo by Heaven Walker.

My next opportunity to see loons was on Lake Namakagon in mid June. As our pontoon slowly cruised through a marshy area of the lake, we kept our eyes scanning the scenery looking for loons. It wasn’t long before we spotted a loon, tucked into the dense reeds and aquatic vegetation, doing their best not to be spotted by us. They were in their nest with their neck and head extended low in front of them, body going as flat as it would go. It seemed to me like they were trying to be absorbed into the reeds to avoid our attention. As a highly aquatic bird, loons only go onto land to nest. By doing this, they are at a higher risk from predators, because they are very poorly adapted to moving on land. To help remedy this, loons nest very close to the waters edge for easy access to the nest, and for easy access to the water. This particular loon's body language on the nest told us that they were stressed by our presence, so we slowly continued on by–doing our best not to disturb them.

This loon's body language indicated they were stressed about our presence. 
Photo by Heaven Walker. 

That day on Lake Namakagon was the first time I saw loon chicks. The cute brown fluffballs with webbed feet were floating around with their parents, learning how to be a loon. I watched as one of the parents dove, and resurfaced with a small fish. Then it was a race from the chicks to see who could reach the parent first, and gobble up their meal. The parents continued to dive and bring fish to the chicks, and the chicks went so far as to attempt to dive themselves. But they never managed to be under for more than a few seconds before their fluffy feathers had them bobbing back to the surface. Diving wasn’t the only behavior the chicks were learning. As I continued to observe the chicks, one of them flapped their tiny wings and stretched vertically into the air. A wing flap! This is a preening behavior done by loons to maintain their feathers, and keep them aligned properly. It was quite adorable, and comical to see the chick wave their wing nubs about.

A baby loon practicing their wing flap. Photo by Heaven Walker

But it wasn’t until finding surprise loon chicks on Lake Owen in mid July that I truly became invested in loons. This pair of chicks were born later than typical, even by second nesting attempt standards. When I spotted them on a Loon Pontoon Tour, they gave me a glimmer of hope for having successful chicks on Lake Owen–as there had been no other chicks on the lake that summer. I instantly became invested in how they were doing. Week after week, I searched for them on the lake. Whenever it would take longer to locate the chicks on the lake, I would get worried that they had fallen victim to a predator. But then I would spot them swimming in the distance, and my worries would be quelled until the next week. As of late August, they were roughly five-to-six weeks old, quite sizable and seem to be doing well.

My summer observing loons was spent taking in all the new information I could on these fascinating birds. I witnessed adult loons call out in warning of an eagle flying overhead, and watched them track its flight as it went by. I watched as they took care of young, preened themselves, dove for food, and swam over to investigate other loons. They have become a new fascination, and I can thank my time in the Northwoods for that.

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Fall Calendar is open for registration! Visit our new exhibit, “Becoming the Northwoods: Akiing (A Special Place). Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

Attack of the Acorns

Crack! Rumble, rumble, rumble. Crack! The sound of hard objects pelting my metal roof shot through my open bedroom window, rousing me from the last wisps of sleep. Then silence. I braced myself as a soft hush of wind drew closer. Crack! The wind triggered a new spatter of noises. The house was under attack—by acorns.

Two large red oak trees reach the edges of their canopies out over the roof of my house. Each fall, they create a racket as acorns drop on the metal roof, tumble down the steep slope, and launch out over the driveway. Some years are worse than others, since oaks are mast trees who will produce a bumper crop in one year, then spend subsequent years rebuilding their stores of nutrients and not producing as many acorns. This is clearly a mast year.

The acorn attack had preceded my alarm clock, but I decided to get up anyway. Taking my coffee with me into the crisp fall morning, acorns nestled in the grass rolled under my feet. I bent down for a closer look at the offending projectiles. The acorns with caps intact captured my attention first. They are the most adorable, after all. And the caps can be helpful in telling apart different kinds of oaks. Red oaks have a low-profile cap with artfully arranged concentric scales. Burr oaks, in contrast, have fringed brims on their acorn caps. Many of the acorns were cap-less though, a pale ring marking the newly exposed shell.

On the driveway, many acorns had been cracked open by my car tires. Some showed pure, cream-colored nutmeat. On others the insides were blackened and bedraggled. I’d read that trees will discard immature acorns that have been attacked by insects or fungi, and they fall to the ground with the cap intact. On the other hand, trees release healthy, mature acorns from their cap, which stays attached to the tree. Was this true?

Gathering up a handful of acorns with and without caps, I got out a cutting board and a Mason jar to use as a nutcracker. I chose a cap-less acorn first. Sure enough, a couple of bangs with the jar split the nut open to reveal intact tissue, ready to fuel the growth of a seedling next spring.

Next, I picked a capped acorn. It looked normal, but from the first tap I could tell it was mostly hollow. Sure enough, when the shell split, I discovered a fat white larva with a brown face had eaten more than half of the two fatty seed leaves called cotyledons that make up the nutmeat. Another capped acorn produced at least four smaller larvae, all eating around the edges. One nutmeat was just shriveled and brown, with some white webby stuff at the bottom—likely a victim of fungi. Wasps, sap beetles, and acorn moths also attack acorns and consume the nutritious tissue inside. In my sample size of 6, all the capped acorns were being attacked, and the bare-headed ones were intact.

I chuckled as I remembered learning this lesson a different way. For our MuseumMobile visits to kindergarten classrooms in the fall, we fill a little cup with acorns. Kids shake the cup, listen to the rattle, and try to guess what’s in there. One fall, our educator filled the cup with fresh acorns, and when we went to show the kids, the cup contained several white larvae, and the acorns each had a small, round hole where they’d chewed their way out.

Likely, they are the young of acorn weevils. These little insects using their long, saw-like snout, called a rostrum, make a tiny hole just under the edge of the cap and lay one or more eggs inside the young acorn. The larvae are fine with the tree’s habit of discarding infected acorns, since they need a ride to the ground. Once there, they tunnel out of the acorn, burrow into the soil, and eventually pupate into an adult weevil.

While some squirrels seem to avoid weevil-infected acorns, others have been observed feasting on the tender protein-filled morsels. Perhaps it’s a question of whether the squirrel is going to cache a nut and needs it to survive the winter, or wants a juicy snack right now. Squirrels might shake or weigh an acorn to determine what it contains, but a quick way for a human to separate viable acorns from predated ones is to do a float test—viable acorns sink and the rest can be skimmed off the top and discarded.

The float test using two of my sample acorns. 

A scratchy rustle on the roof made me look up from the pile of cracked acorns just in time to see a full oak twig launch off the roof. Two fluffy gray squirrels looked guiltily down from the branches. A cluster of empty acorn caps on the lower part of the twig marked the tree’s success—or maybe a squirrel’s full tummy? Out toward the tip, though, in the axis of each leaf, were what looked like miniature acorns forming from the remnants of female flowers.

The squirrel who had tossed this twig onto my roof did me a favor—female oak flowers only occur high in the canopy and are hard to see. The male flowers—dangly yellow catkins that release pollen—are much easier to observe in the springtime. Once pollinated, the female flowers bide their time, and don’t fully mature until their second summer.

Unfortunately, what this squirrel also showed me is that next fall might be noisy, too!

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. Natural Connections 3 will be published in November 2025!

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Fall Calendar is open for registration! Visit our new exhibit, “Becoming the Northwoods: Akiing (A Special Place). Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

Shades of Rot and Life

Author’s Note: This essay is a chapter from Emily’s third book, Natural Connections 3: A Web Endlessly Woven, which will arrive in November 2025!

In the dim light, under the thick, hardwood canopy of the forest, death was everywhere.

Autumn leaves carpeted the ground in shades of brown and yellow with occasional splashes of blood red. Snags stood among the living trees, their decorticated (a fancy term for barkless) trunks smooth and dry. And long stripes of rusty brown crumbles marked where fallen logs were melting into the ground.

Of course, life was everywhere too.

Beside the wide, dirt trail, a ruffle of turkey tail fungus cascaded down the graceful curve of a tree trunk like an earth-toned ball gown: a damsel of decay. While the volume of fungal frills—each with a velvety top, concentric bands of color, and tiny pores in the white undersurface—was impressive, the bulk of the being was hidden inside. Intertwined among the wood cells, hidden from view, the fine, white threads of hyphae (the actual body of a fungus) were hard at work. The tree was dead, and yet, still full of life.

Turkey tails are a white-rot fungus, which means that they have the ability to decompose the major components of a tree. That’s not easy. Wood is tough because the cellulose and lignin molecules it’s made of are long chains of elements that are difficult to break apart. Lignin in particular gives wood its strength.

Turkey tail fungus is rotting both the cellulose and the lignin in this log. Photo by Emily Stone.
 

Do you remember learning about enzymes in your high school science class? I chewed on a saltine cracker until it became sweet. Enzymes in my mouth broke down the long chains of starches until they became glucose, a simple sugar. In a similar, but external process, fungi exude a series of enzymes into the wood, and those enzymes split the chemical bonds of cellulose and lignin, resulting in shorter chains of glucose. The sugar dissolves in water, and fungal hyphae absorb it directly through their cell walls. Carbon dioxide is released to the air.

Because turkey tail and other white-rot fungi break down cellulose and lignin simultaneously but leave some of the cellulose for last, the wood they work on becomes white and stringy. A large portion of the nutrients once trapped in the wood become available to cycle through the ecosystem again. Bacteria move in to use those nutrients, paper wasps turn the pliable fibers into nests, and moose eat wood softened by artist's conk fungi.

The next day, I headed back along that same trail with a group of Wisconsin Master Naturalists doing an activity called a “Professor Hike.” I picked a student with a sense of humor, stationed her by a stump, and made her a duct tape nametag that read: Professor Brown Cubical Butt Rot. “This isn’t a disease caused by too much time in an office chair,” I joked. The name is real and quite descriptive.

As the professor explained to her classmates, this tree stump was being decomposed by a brown-rot fungus. Unlike the turkey tail, some fungi can only decompose the cellulose in wood cells, and the lignin left behind is brown. The fungus typically affects the bottom of a tree trunk, which in forester and logger lingo is the “butt.” But the cubical part of the name is most interesting.

Brown-rot fungi send hydrogen peroxide rapidly diffusing through the wood of a tree. The chemical modifies lignin just enough to get at cellulose also in the cell walls and snips apart the long chains of cellulose into carbohydrates. Two days later, once the destructive peroxides have dissipated, enzymes finish the job of turning the carbohydrates into sugar. The fungus absorbs it.

The process works more quickly than the totally enzyme-dependent decomposition by white-rot fungi but leaves all the lignin on the table. The lignin-rich wood turns brown, shrinks, and cracks into roughly cubical pieces. Hence the name, brown cubical butt rot. The “professor” bragged about her name all day—inadvertently teaching about decomposition along the way.

We’re often tempted to turn everything into a competition. Are white-rot fungi superior because they can break down lignin? Or are brown-rot fungi better because they can work more quickly? In fact, the first to arrive often has the advantage. And when the two types of fungi compete directly on the same log, brown-rot fungi win the short game by being able to access the energy in cellulose quickly, while white-rot fungi play the long game as they slowly devour more of the energy stored in the wood.

In the end, the ecosystem wins. The rusty colored crumbles of brown-rot fungi contribute to healthy soils with more capacity to hold moisture and nutrients. White-rot fungi, and especially competition between several different types of fungi, results in a tree being more thoroughly recycled and the materials becoming available for new growth. Humans are also treated to delicious meals when the fungi fruit. My favorite—chicken of the woods—is a brown-rot fungus. Shiitake and oyster mushrooms, plus medical turkey tails, are all white-rotters. Lignin and cellulose; brown and white; death and life. In the end, they aren’t all that different.

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. Natural Connections 3 will be published in November 2025!

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Fall Calendar is open for registration! Visit our new exhibit, “Becoming the Northwoods: Akiing (A Special Place). Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

Mysterious Loon Behavior

“Two loons! Over there!” one of the participants on the Loon Pontoon Tour on Lake Owen pointed behind our boat. Our volunteer driver swung around and puttered toward the two birds slowly, so as not to disturb them.

The loons faced each other, dipped their bills in the water, swam so they were head-to-tail in a circle of two, then dove in opposite directions. Surfacing after just a moment, they started again. After repeating this sequence several times, they appeared to tire. For a moment they drifted in parallel. Then one loon rose up from the water, flapped their wings, shook their head, and settled back down. Almost like a contagious yawn, the second loon followed suit. It seemed for a second like the loons might relax, but back in the water, they started from the beginning with head-to-tail swimming, beak dips, and dives.

When loons are establishing a pair bond or social connection, I explained to the group, they swim in parallel with their beaks angled away. Because sharp beaks are their most formidable weapon, where loons point them is significant.

I sent videos of the interactions to Jay Mager, the loon researcher I’d studied with on Lake Jocassee, South Carolina, last March, and he explained that this type of circling creates anxiety because the loons are frequently in each other’s blind spots and fear a surprise lunging attack. Fighting among loons frequently results in injury or death.

On the other hand, Jay has also witnessed interactions like this, especially in winter, de-escalating into side-by-side swimming and then social interaction and even cooperative fishing.

Throughout the summer, we’d observed a pair of loons in this northwest bay of Lake Owen. In past years, they’d had good luck producing chicks. Although we suspected that they had a nest this year, we never saw young ones on the water. Could these loons be the territorial pair? The aggressive behavior seemed to indicate that no, this was more likely one of the bay’s “owners” and an intruder.

We’d only been watching for a few minutes when suddenly one of the loons (the intruder?) took off running and flapping down the bay toward the main lake. Huge, webbed feet splashed at the surface. Loons have the heaviest body for the smallest wings of any bird who can still fly. Just like a jet airplane, they require a long runway to gain the speed and lift necessary for takeoff. Once airborne, they are strong fliers who must keep up their speed to stay aloft.

As soon as the first loon rose above the water, the remaining loon (the resident?), who had been floating near the pontoon, followed in a flurry of flapping wings and feet.

What had just happened? The group looked around at each other in amazement, feeling lucky to have witnessed this fascinating bit of loon behavior. Jay Mager summarized our feelings when he wrote to me: “Situations like what you saw the other day epitomize why I enjoy watching loons so much—I sometimes wish they could tell me a little bit more about what they're doing and thinking, but that might make it less 'magical' in a way.”

As the pontoon bobbed in the light breeze, I tried to use what we’d seen to help the group understand more about ecology of loons. One thing we’d noticed was that both loons showed a bit of white on their faces, near the base of the beaks. This is the beginning of their fall molt. They’ll completely replace their feathers once they migrate south to the ocean or a big lake.

Despite a pair of loons still caring for two fuzzy chicks in another part of the lake, the white feathers are a reminder that loons are preparing for winter. Loons will not only change their color to a gray brown, they will also shift their behavior from aggressively territorial against anyone except their mate, to social and cooperative. Loons may join up in rafts of 3, 10, or even 20 or more birds as they stage for migration. Changes in hormones probably help with this shift, as well as the benefits of sharing information, fishing together, and not wasting time fighting all year. That said, loons with established territories may still be warding off intruders and making sure that they’ll have a home to return to next spring.

Grow faster, fluffy chicks! Photo by Emily Stone. 

We’d just started to motor forward again when the faint sound of wing beats echoed across the water. The distinctive, torpedo-shaped, hump-backed silhouette of a loon in flight appeared against the sky for just a second before dropping below tree line and skimming smoothly across the surface of the water. Although this loon returned quickly today, very soon they will be making a much longer flight. We’ll miss their presence here when our lakes turn to ice, but I’ll be looking forward to observing more of their fascinating behavior on our weekly Loon Pontoon Tours when they return in the spring.

Watch the video of their behavior here: https://youtu.be/9FL9Qng2d0s 

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. Natural Connections 3 will be published in November 2025!

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Fall Calendar is open for registration! Visit our new exhibit, “Becoming the Northwoods: Akiing (A Special Place). Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.