The Mystery of Mast Years

Last week I wrote about acorns clattering across my roof. As it turns out, nuts are raining down on many of your roofs, too! Commiserating over the loud, foot-rolling acorns makes me feel like part of an extended community. Are the oaks part of a similar community? And why are they suddenly attacking us with acorns!

Oaks are mast species, which means that all the trees in an area will produce a bumper crop of acorns at the same time, but only every two to five years. With hundreds of thousands of acorns available, the trees ensure that at least some of them will escape being eaten by chipmunks, squirrels, turkeys, blue jays, deer, and bears and survive until they can sprout and grow. This is known as predator satiation.

Red squirrels are seed predators on acorns.

In non-mast years, the acorn seed predators still survive, but at lower rates. When the oaks do mast, there aren’t enough critters to eat all of the acorns. The seed predators feed greedily and reproduce, but when there are few acorns the following years, their populations drop again. By being unpredictable with their mast years, oaks prevent seed predators from syncing up with the trees.

This same idea applies to parasites. Acorn weevils, knopper gall wasps, and acorn moths lay their eggs in developing acorns so that their larvae have an easy meal. A bacterial pathogen takes advantage of the holes they chew and causes “drippy acorn disease.” The result is the same as a chipmunk eating the seed, but the process takes longer. In addition, the parasites and pathogens are often closely tied to the acorn as a food source, and may not have other options. Chipmunks and other seed predators will eat from an extensive buffet of foods when acorns aren’t available.

While teaming up to satiate seed predators is clearly a good strategy for oaks, scientists are not so clear on how the trees coordinate, sometimes across hundreds of miles. It can’t be totally weather or resource driven, since variations in rainfall and temperature don’t fluctuate as much as the number of acorns produced. Certainly, an oak can’t produce tons of acorns if they are not healthy. But a year with plenty of rain doesn’t automatically result in acorns. During mast years a tree’s growth slows, so sometimes the trees need to put abundant resources toward making wood, not seeds.

One hypothesis about how oaks coordinate their mast years that seems to be gaining support in the scientific community is pollination efficiency. Oaks are wind pollinated. Their male flowers are dangly catkins that release pollen into the wind. The pollen needs to reach the pistils of the much smaller female flowers in order to fertilize the nascent seed. When oaks produce a ton of flowers at the same time and then have warm, dry weather, more female flowers will receive their dose of pollen. If the number of flowers oak trees produce fluctuates from year to year, this could translate into variable seed production, too. According to one study, this is true in “soft” climates, but not the Northwoods.

In harsh climates like ours, oak trees produce about the same number of flowers every spring. Having warm, dry weather that allows flowers to be pollinated AND to develop into acorns is essential, says Dr. Andrew Hacket-Pain who has used data from the Nature’s Calendar Phenology Project to study the correlation. A rainy spring, late freeze, or ice storm can easily ruin everything. Knowing how patchy storms can be in the Northwoods, I’m hesitant to believe that this could coordinate mast years across huge distances.

“In the old time, our elders say, the trees talked to each other,” wrote Robin Wall Kimmerer in her book Braiding Sweetgrass. Do they gossip about the weather like most Northwoods neighbors? Some mycologists theorize that the networks of mycorrhizal fungi who connect a forest by the roots may be the agent of coordination for mast years. “A kind of Robin Hood,” wrote Kimmerer, “they take from the rich and give to the poor, so that all the trees arrive at the same carbon surplus at the same time. Through unity, survival. All flourishing is mutual.”

Mice certainly flourish alongside acorns in mast years. The abundant food source means they have more babies. The same is true for the mice’s predators. Foxes, weasels, ticks, and even saw-whet owls may increase in number when mice are abundant. I’m excited for the potential uptick in owls, because the Museum has just started to recruit volunteers to help with a saw-whet owl study in Bayfield County. Check our calendar of events for details!

From mice to owls to chatting neighbors, oaks, and the mystery of their mast years, are at the center of our Northwoods community.

Author’s Note: Portions of this article are reprinted from 2015 – which was another mast year!

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.

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.

A note from my post of this photo to BugGuide.net:

This looks more like a Lepidoptera larva to me, but I'd need to see it from different angles to be more confident. Some moth species are known to feed inside acorns as larvae.

… John van der Linden,

… John van der Linden,

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.

A Blue-Spotted Vision

Although the temperature plummeted and rain ran off our jackets, our excitement and determination could not be dampened. Rubber boots tromped over soggy leaf litter, and hands grasped at every fallen log, flipping them over as we searched the forest. The Wild Wonders campers and I were on a mission, seeking out an animal who thrives in rainy conditions–the salamander.

Enthusiasm began to dwindle as each log we flipped yielded no amphibian friends. I began to wonder if we would be successful in our pursuit. Then, mid-flip of a log, a camper let out a yip of surprise. “Salamander!" In an instant, the other kids abandoned their own logs and dashed through the damp ferns to jockey for a closer look.

My excitement paralleled the campers. We had found a blue-spotted salamander! The little four-legged being waved their tail back and forth at us. To the campers, it seemed like the salamander was waiving hello. In reality, we were being told to back off. When feeling threatened, blue-spotted salamanders will stand their tail up and wind it back and forth in an S shape in an attempt to make themselves seem bigger and more threatening. It didn’t work to scare us off, but not wanting to cause more stress for our friend, we said goodbye and gently rolled the log back over their hiding spot.

Wild Wonders campers and their blue-spotted salamander! Photo by Heaven Walker.  

I had hoped that we'd find some kind of salamander on our rainy excursion, but seeing this particular species was a big surprise. Growing up in Iowa, I only knew of the blue-spotted salamander as being a rare, state endangered species only found in two counties. A little research soon told me that in Wisconsin they are common across most of the state. This got me thinking, why are blue-spotted salamanders endangered in Iowa, but not in Wisconsin?

Blue-spotted salamanders are forest dwellers. They are relatively secretive, taking cover under logs, leaf litter, and other forest debris to keep from being seen. Here in Wisconsin, they inhabit both hardwood and coniferous forests across the state. With roughly 46% of Wisconsin being covered in forest land, they have a wide range of potential habitat available. Comparatively, only 8% of Iowa is covered in forest habitat.

Blue-spotted salamanders also need vernal ponds for laying eggs and for their larvae to develop over several weeks. These ponds form in the spring, and are typically dried up by summer. Because the ponds dry up, they cannot support fish, and have fewer predators for salamander larvae.

Blue-spotted salamanders also like damp, sandy soil that’s easy for them to burrow into for the winter. Taking a look at forest cover and soil maps, I discovered that the two Iowa counties where blue-spotted salamanders are found have both sandy soil and a little bit of forest cover. Mystery solved!

Close up with a blue-spotted salamander. Photo by Emily Stone. 

On the other hand, there are two other Iowa counties that have the sandy soil and forest cover overlap but have no recorded populations of blue-spotted salamanders. Salamanders are sensitive to disturbances within their habitat. Habitat fragmentation can limit their access to breeding areas, cause fatalities when migrating to breeding ponds, and limit reproductive success. The siltation of vernal pools would also be detrimental to salamander populations. At a glance, the habitat may appear right, but without a closer look it is hard to be certain.

The longer I live in the Northwoods of Wisconsin, the more I find to appreciate about the diverse nature of this place. While there is some overlap in the flora and fauna of my home state and northern Wisconsin, I’m grateful for the opportunity to discover the differences between the two states, and encounter new plants and animals!

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Summer 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.

Unexpected Hope

Rounding the bend in an old two-track road, our group gaped up at the huge greenish-gray pile of dust that towered above. With weeds growing on the sloped sides and back, and an almost vertical cliff facing us, the landform felt like a poor quality model of the magnificent Half-Dome in Yosemite National Park. Our boots made tracks in the fine sediment under our feet, and water had made tracks and grooves down the steep face of the pile.

Bill Tefft, leader of the Ely Field Naturalist group, explained to participants on the Cable Natural History Museum’s Landscape Ecology in Northern Minnesota program that this was the waste material from a long-closed operation that quarried greenstone bedrock, crushed it into material for asphalt shingles, and then made a pile the stuff that got too powdery. “It extends all the way down to the railroad tracks,” Bill told me as we peered over a steep, forested bank. Green Mountain wasn’t just the cliff, it was the entire area.

"Green Mountain" near Ely, MN

We followed the old two-track as it curved down around the side of the pile through thick forest. The group stopped and gawked in awe at the shore of a glimmering lake surrounded by artfully rugged greenstone cliffs. Calm water reflected the lovely patchwork of a mature forest. A few cattails took advantage of the shallow water where the gentle slope of this old road disappeared into the lake.

Participants on the Cable Natural History Museum’s Landscape Ecology in Northern Minnesota program gaze at the beautiful lake that has formed in an old greenstone quarry. Photo by Emily Stone.

According to Bill, the quarry operation had to stop about a hundred years ago when they unearthed a spring and water poured into the hole. Rumor has it that some of the mining equipment is still at the bottom. But why were we here on a natural history field trip?

Tom Fitz, geologist extraordinaire, explained that this greenstone bedrock represents a time in Earth’s history about 2.79 billion years ago when lava erupted from the seafloor in a world that was almost entirely ocean. Subsequent action by plate tectonics buried the hardened lava. Heat, pressure, and time transformed some of the components into greenish minerals, and it became a rock called greenstone that’s common around Ely, MN. This is some of the oldest rock exposed at Earth’s surface. Unnatural as they may feel, roadcuts and quarries provide some of the best opportunities to observe this slice of history.

Tom Fitz explains the formation of the Ely Greenstone in front of "Pillow Rock," a landmark in Ely, MN. Photo by Emily Stone.

I was just about ready to round up the group and move on when someone exclaimed over a pretty white flower among the weeds. Five luminous petals, each with translucent lines arcing gracefully toward the nectar reservoir in the center, provided the backdrop for a ring of delicate eyelashes tipped with glossy yellow spheres. I could barely believe my eyes!

Bog star or marsh grass-of-Parnassus is a lovely little flower of cool, damp places.
Photo by Emily Stone.

I first met bog star, or marsh grass-of-Parnassus, during my summer in Alaska while assisting with a snowshoe hare study in the Brooks Range. This little beauty captured my imagination immediately. Their range map includes most of Europe and plenty of other places in the Northern Hemisphere, but in Wisconsin, Minnesota, and Michigan, they are harder to find. Except where they’re not! Once we started looking, more than a dozen bog stars appeared among the weeds.

I first met Bog Star on my sabbatical to Alaska in the summer of 2018, and painted a postcard of it when I returned. 

The information in the iNaturalist app, when we used it to confirm their identification, mentioned that marsh grass-of-Parnassus is an indicator of the damp, calcareous soil in fens. Calcium-rich soil isn’t common in the Northwoods, since the ancient oceans that deposited limestone were mostly farther south. “Could there be something in the pulverized greenstone of the green mountain that would result in calcareous runoff?” I asked Tom. “Yes,” he answered. In fact, we’d just seen veins of the mineral calcite (calcium carbonate, the same mineral that’s in limestone) in a chunk of greenstone earlier that morning.

Bill Tefft shows us a giant drill core of greenstone. It was removed to provide air flow into an iron mine. Tom spotted calcite veins in the core. Photo by Emily Stone. 

After taking a zillion photos of these beautiful flowers, I stood to stretch my back and gaze out over the quarry lake again. How odd, I thought, that this rare friend would be growing in place so impacted by humans. And yet, sorting through old memories from Alaska, I realized that I’d found that first bog star in the gravel beneath the Trans-Alaska Pipeline that carries oil from Prudhoe Bay.

Can you spot the silver snake of the pipeline in the middle of the Brooks Range, Alaska?
Photo by Emily Stone.

For a moment, my delight in finding this flower diminished. Wouldn’t it be better to find them in a pristine wetland, untouched by the industrialized footprint of humans? But what part of the Earth is truly untouched? Not only have Indigenous peoples been living in relationship with the Northwoods ecosystem since the glaciers retreated, the impacts of modern humans include dropping mercury, microplastics, and DEET into even the most remote lakes, and changing the patterns of temperature and rainfall over wilderness and cities alike.

And yet wild nature, beautiful nature, survives. That doesn’t give us license to pollute and destroy without restraint. Instead, it gives me hope that if we are careful in how we use the Earth’s natural resources—Natural Gifts, in the words of Robin Wall Kimmerer—the ecosystems who sustain us can heal. With this thought, it was as if the Sun had emerged from a cloud, and the little white bog stars shone brightly again.

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.

Further Observations of Forked Fungus Beetles

Katherine Woolley is about to start her junior year as an environmental education major at Western Colorado University. This summer, as a Summer Naturalist Intern at the Museum, she taught our Junior Naturalist programs and showed a real talent for finding and appreciating the oddest parts of nature.

I was dragging my feet on a sunny afternoon after a long day of sitting in front of my computer lesson planning and preparing supplies for my upcoming Junior Naturalist program I co-run with my fellow intern. I didn't really feel like going on a hike, but the urge to go see what my forked fungus beetles were up to ended up outweighing my desire to sit on the couch and never leave. Since my first sighting of them this summer, I've found plenty more shelf mushrooms that house beetles. Thanks to their stationary lifestyle, I have been able to get to know each pair quite well and identify their home polypore easily. Today, I was on my way to see my favorite male and his mate.

I spotted the male first. He was sitting on the highest point of the mushroom shelf like he was the king of the hill. Then I spotted his mate, who to my surprise, looked like she was sitting up. I knelt down and cocked my head to the side to get a better look. For beetles who usually crawl on all six legs, this was an unusual position. Was she laying eggs? I couldn't be quite sure.

I searched carefully for egg capsules in the spot where I first saw this beetle. Sure enough, there was a little line of eggs! Female forked fungus beetles lay 8 to 12 eggs on the surface of their polypore or just below the surface. Eggs are laid one at a time and then covered by a sticky black material created by the female. This material is placed to the side of each egg when it is first produced and then is spread over the egg using little hairs that grow on the underside of the female's abdomen.

Female Forked Fungus Beetle using her Ovipositor to lay eggs. 

Photo by Katheine Woolley

Focusing my attention back on the female’s current location, I witnessed more of the egg laying process. By this time the beetle was up higher on the fungus and I was able to see her ovipositor at work. Her ovipositor was small, black and cone-shaped with the narrower part toward the bottom. What a treat to see! Then I got just a little too close to her and she retracted her ovipositor back into her abdomen.

I was so enraptured with watching the egg laying that I almost missed the process that occurs before eggs can even be laid. On the fungus shelf to my right, I saw another female with a male directly on top of her. In an instant I realized what was happening and my face grew red. After the initial shock of interrupting an intimate moment between fungus beetles, I started to giggle.

Like many other insects, the copulation process begins when the male climbs onto the back of the female. In the case of forked fungus beetles, the male climbs on so he is facing the opposite direction of the female. Then the male will use his legs to hold onto the female's wing coverings that are called elytra. Forked fungus beetles have proven to have phenomenal grip strength, and they most certainly need it. The two forked horns that adorn the males’ heads are not just for show, they are for prying other mating males off of females. If male fungus beetles want to pass on their genetic material, they have to be really good at holding on to avoid getting dislodged by a competing male.

Forked Fungus Beetle Copulation.
Photo by Katherine Woolley

After I snapped some pictures, I realized I was definitely interrupting and should probably back off. I checked on the female who was laying her eggs just a minute ago, but she was gone. I scolded myself for getting too excited about documenting what I was seeing and scaring her away during such an important moment. I whispered an apology to all the beetles who occupied both of the fungi and backed away, promising to give them some space for the next few days. As I walked home, I was so grateful I had chosen to go on a hike that day even when I really didn't want to. If I hadn't, I wouldn't have gotten to watch beetle life in the making. Yet again, I was shown that walks on the Forest Lodge Nature Trail are truly never boring.

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Summer 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.

Finding Forked Fungus Beetles

 

Katherine Woolley is about to start her junior year as an environmental education major at Western Colorado University. This summer, as a Summer Naturalist Intern at the Museum, she taught our Junior Naturalist programs and showed a real talent for finding and appreciating the oddest parts of nature.

A walk along the Forest Lodge Nature Trail is never boring. I was reveling in this fact as I took my evening meander through the large trunks of towering trees. To my left, I spotted a shelf fungus clinging to the bark of a half-decayed paper birch stump. Creeping closer to investigate, I peered up, to the side, then the other side. Then I crouched down and took a good look at the underside of the fungus, my eyes squinting in the bright evening light. I squealed with delight. There they were! Two forked fungus beetles were nestled in the corner of their polypore home.

Despite being one of my favorite insects, this was only the second time I had ever been gifted with their presence. My first encounter with forked fungus beetles was almost two years ago but only a few miles away on a Northland College field trip to the Forest Lodge Estate on the south shore of Lake Namakagon. While there, a fellow classmate and I roamed the grounds together. We first spotted a shelf mushroom, and then when investigating further, spotted a weird brown bump. Looking closer, the bump had legs, antennae, was moving, and was not actually a bump at all, but an insect.

Female forked fungus beetles lack forked horns. Photo by Katherine Woolley.

With a gasp of awe, I called my other classmates and professor over to see this amazing creature, but not a single one of us had ever seen one before. Later I found out through the iNaturalist app that this insect was a forked fungus beetle. These beetles only live east of the Mississippi River. Until my move to Wisconsin from where I had grown up in Minnesota, I had lived west of their range. After that encounter, my friend and I spent the following summer scouring the forests to find another beetle, but to no avail. That made it even more thrilling to spot these two beetles this summer.

Male forked fungus beetles have two horns that they use to fight with other males. Photo by Katherine Woolley.

The particular mushroom where I spotted the beetles that day was filled top to bottom with a wide and intricate network of holes. While searching for beetles, I discovered that holes like the ones I saw are a great indicator that fungus beetles are present. This is because their larvae are the ones who create these holes by burrowing inside the woody polypore after they hatch from eggs that are laid on the outside of the mushroom.

Once inside the polypore, the beetle larvae go through their final two stages of metamorphosis—pupae and then fully formed beetles—rather peacefully by giving each other a wide birth. Even so, if a larva happens to stumble across a pupa who is still forming into a beetle inside the mushroom, they may eat that pupa! Pupae who survive the hungry mouths of their brothers and sisters emerge from their pupal cases a pale whitish yellow. After emergence, the beetles stay in their cases for a few days until they develop their characteristic deep woody brown and wet-bark-black colors.

Forked fungus beetles can spend the winter in either the adult or larval stage. Adults hide safely tucked into fungus, stumps, logs, and other decaying wood to wait for warmer weather. The larvae stay snug inside the polypore tunnels and then start their transformation in spring. Generations of the same beetle family will live on the same mushroom for up to nine years, moving onto a different polypore when the clutter of holes becomes unlivable.

An old polypore home abandoned by forked fungus beetles. Photo by Katherine Woolley.

After I snapped some pictures, I wondered if I kept coming back to this stump if I would see them again. When forked fungus beetles are born, they don't often go far. These beetles can fly, but they very rarely do. I took a final look at the shelf mushroom, looking for eggs. Finding none, I bid my beetle friends farewell. As I traveled farther down the trail, I stopped at every shelf mushroom with hopes to discover more fungus beetle strongholds, but there were none. I suppose their elusiveness is part of what makes seeing them such a treat. I smiled in gratitude at their stump on my way home.

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Summer 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.

Seeds on the Move By Kylie Tatarka

Kylie Tatarka is about to start her senior year as an environmental science major at Rochester Institute of Technology. This summer, as a Summer Naturalist Intern at the Museum, she taught our Junior Naturalist programs and spearheaded the creation of the online “Becoming the Northwoods” exhibit.

While leading a group of Junior Naturalists from Wayside Wanderings Natural Play Area back to the Cable Natural History Museum, we came across a field covered in snow. Snow? In July? What we actually saw was a blanket of aspen seeds across the lawn. These seeds are attached to cotton and when they detach from the seed pods in June, the wind picks them up and carries them away to a new home.

The fluffy coating on aspen seeds carpets the grass like snow in July. Photo by Kylie Tatarka.

Maple seeds also disperse on the wind, using a helicopter spin to move farther from their parent tree and find more space to grow. As a kid I enjoyed when maple tree seeds were falling from their trees, as the helicopter seeds fell in mesmerizing flights through my town parks. My sisters and I would pick them up and force them to whirl downwards again as the wind blew them around.

Seeing the aspen-covered ground reminded me of a tree that is more common in my home state of New York, the eastern cottonwood tree, which is a relative of the aspen with similar cotton-tufted seeds. I grew an affection for these trees while leading a seed dispersal hike. With the kids, we discovered examples of seeds that are dispersed by wind, water, animals, gravity, and bursting. Now I’m always on the lookout for plants with interesting methods of seed dispersal.

While exploring Lake Namakagon in a kayak this summer, I ran into a plant that I don’t often see in New York, the yellow water lily. Their seed heads burst open and the seeds fall onto the surface of the pond or lake where they live. The seeds are then transported to new locations through the movement of the water, reaching places far from their parent plant.

Yellow water lilies produce seeds that float to new homes. Photo by Emily Stone.

Plants living beside water can also have seeds transported by water, as long as their seeds float, which is the case for the example I used in my dispersal hike, the weeping willow. This tree thrives on the shorelines of ponds and lakes. Their seeds have a light, fluffy casing, similar to the aspen and cottonwood trees, which allows for the seeds to float on top of water.

The next example from the seed dispersal hike has been the most memorable to me. Why? It contained every kid’s favorite topic, poop! Wild grapes are eaten by animals who then poop out the seeds. This fact always forced a pause in the hike so that all of the laughing kids could breathe again. Once they were calm, I explained that the seeds are pooped out into a new part of the environment which helps in creating less competition between the wild grape plants. Since moving to Wisconsin, I’ve been on the lookout for bear scat full of berry seeds, too.

Bursting, or ballistic dispersal may be the most exciting form of seed dispersal. I haven’t seen this yet, but many of my fellow naturalists have raved about the jewelweed's seed pods. When the seed ripens in August, any touch will cause them to burst open and a spring loaded mechanism will send the seeds flying. I can’t wait to witness that!

Jewelweed flower. Photo by Emily Stone. 

 

Jewelweed seed pod. Photo by Emily Stone. 

Jewelweed burst seed pod. Photo by Emily Stone. 

The mechanism of each seed and how it is transported is a result of centuries of evolution. However, the ability to be dispersed does not guarantee the success of germination for the seeds. A maple tree can produce thousands of seeds a year, but only a small percentage of those will sprout and even fewer will become trees. Dispersal only works if it brings the seed to a site that has the conditions of growth that the seed needs.

Whether they grow or not, each seed is crafted with adaptations to help them disperse. Each seed is special and carries long evolved characteristics that we may or may not think of on a daily basis until it looks like it's snowing in July.

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Summer 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.