The Subnivean Zone Returns

Lake Superior was astonishingly calm as we walked out to a rocky point in the last rays of the setting Sun. With no wind and temperatures well above normal for late November, my fiancé and I only needed light sweaters and jackets to stay warm. It was a truly lovely day to be outside.

Lake Superior on a calm November, day. Photo by Emily Stone.

Lake Superior on a calm November, day. Photo by Emily Stone.

“Grandfather Alden would have called this a ‘weather breeder,’” I told Kevin. He didn’t read The Boxcar Children books by Gertrude Chandler Warner, but they were a staple of my childhood. In this early reader series, four brave siblings solve quaint mysteries with the help of their wise grandpa. In Snowbound Mystery they spend a glorious, bluebird day hiking around a mountain cabin before a blizzard socks them in. Their Grandfather called the bluebird day a “weather breeder.”

On The Weather Channel’s website, I found this explanation to confirm Grandfather Alden’s usage: “According to a late 19th century definition, a weather breeder is a beautiful day of ‘unusual fineness’… However, such a day is usually followed by bad weather.” A 1996 article about weather adages in The New York Times explains that the only science behind that saying is the law of averages. Good weather doesn’t cause bad weather, but since the weather is always changing, your good weather will soon turn to bad. Checking my weather app, I was thrilled to see the amount of snow in the forecast going up yet again. This day was certainly the calm before the storm!

Cold rain splattered my windshield the next day as I headed back to the shores of a smaller lake in Northern Wisconsin. Before cozying up indoors, I wrapped my digital thermometer in plastic wrap and tucked it under the bright green frond of an evergreen wood fern in the yard. This has become an annual ritual. On the weather station screen indoors, I could see that the newly placed sensor matched the air temperature in the mid-30s.

Can you see the white corner of the temperature sensor hidden under the fern?
Photo by Emily Stone.

Overnight, the wind howled and rain turned to snow.

As winter’s first snowflakes drifted through the dark, some landed on top of dead plants, fallen leaves, twigs, and other detritus of the forest floor. In many places, snow never fully reached the ground. That was surely true for the protected hideaway of my thermometer. By dawn, it was buried under six inches and counting.

Despite falling temperatures, the relative warmth of the cold rain and the residual heat of summer were still radiating from the soil. At sunrise, when I checked the weather station, the air temp had dropped to 24 degrees Fahrenheit, but the sensor cozied up to the earth under a fresh blanket of snow read 33 degrees. After two winters of thin snow, the Subnivean Zone has returned!

All winter long I will monitor the air temperature and the temperature of a thermometer I recently buried in the Subnivean Zone under the snow. In it’s first day of existence this winter, the Subnivean Zone did not drop below 33 degrees! Photo by Emily Stone.

In this magical space, with a blanket of snow to trap the earth’s warmth and provide a solid break against the windchill, temperatures hover around freezing even as the world above drops below zero. Deeper snow provides even more insulation, and all manner of Beings—from mice to martens, bacteria, fungi, spiders, hibernating insects, frozen wood frogs, and more—rely on the moderated microclimate.

In 2022-23—the winter of record-breaking snow—deep drifts accumulated on still-thawed ground, and the temperature in my front yard’s subnivium didn’t drop below 32 degrees for the entire season. The last two winters haven’t been so lucky. With thin, icy snowpacks, plant roots and mosses felt the sting of dry, bitter cold, ruffed grouse couldn’t dive into a snow cave to spend the night, and small mammals had to face the choice of staying safe and warm in a burrow, or risking being eaten or dangerously chilled while they foraged for food. Wood frogs in the leaf litter suffered without snow to buffer them from energetically costly freeze-thaw cycles.

Happily, at least for this week, those Beings are safe from the challenges of a snowless winter. Those Beings include me. Cold weather without groomed ski trails makes me sad. This week, my social media feed is full of good news about trails opening.

A weather breeder might be a day of “unusual fineness”, but I personally wouldn’t call what came after it “bad weather.” For many Northwoods Beings (the ones who don’t have to drive on bad roads or clear downed trees) snow and The Subnivean Zone are truly something to be thankful for!

Fluffy snow is a wonderful insulator to help retain warmth from the earth. Fluffy snow is also great for skiing up a gravel road! Photo by Emily Stone.

Emily’s brand-new third book, Natural Connections3: A Web Endlessly Woven, is available to purchase at www.cablemuseum.org/books and at your local independent bookstore, too.

https://www.cablemuseum.org/books/ 

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

The Bright Red Warning of Barberry

“A long time ago, the owner of that cornfield asked if I would sell this little piece of relatively flat woods to him,” my dad told me while walking me through a section of my parents’ land in Northeast Iowa. “He talked about cutting the trees and growing more corn.” As I looked out through the furrowed trunks of white oak, hackberry, chinkapin oak, walnut, basswood, and sugar maple to the monoculture of the field beyond, I was glad Dad had said no.

We’d just scrambled down the steep slope of our North Ridge. Looking back uphill, blocky outcrops of limestone nosed through a thick layer of autumn leaves. As part of the Driftless Area, this land has been shaped by flowing water instead of ice. The Turkey River—a tributary of the mighty Mississippi—had carved this ridge in one of its meanders through its floodplain. From the top of the North Ridge, we’d been able to look almost straight down at the channel carving the other side, too.

My dad, Larry Stone, looks from our North Ridge down to the Turkey River in NE Iowa. Photo by Emily Stone.

We sat down on a fallen log for a moment. Dad adjusted the cloth “tick gaiters” treated with Permethrin that he always wears out hiking these days. Iowa has plenty of deer and deer ticks, and multiple encounters with Lyme disease have made him cautious. The gaiters work on the same idea as tucking your pants into your socks to keep ticks from crawling into hard-to-see places. The addition of Permethrin means that the ticks aren’t just detoured, they die.

The pause also gave Dad a chance to snap a few photos of the late afternoon sun streaming through the trees. As I followed his gaze, a low bush with pinkish leaves off in the distance caught the light in a way that nothing else in the forest did. Hmm.

Japanese barberry bushes keep their rosy, red fall colors for a long time and are easy to spot in the November woods. Photo by Emily Stone.

The closer we ambled to this bush, the more sure I became of their ID. Finally, a close look revealed a few bright red, football-shaped berries dangling from rosettes of small, pink leaves. My hunch was confirmed. This was a Japanese barberry.

The bright red berries of Japanese barberry are one of the reasons this plant was favored as a decorative addition to landscaping until they began escaping gardens and becoming a haven for deer ticks and Lyme disease. Photo by Emily Stone.

The arching stems, decorative berries, and warmly hued, persistent fall foliage of barberry, plus the complete lack of deer browse on their twigs, are why they were brought to the U.S. as an ornamental plant in 1875. That was fine, until in the 1980s they started to spread out and displace native plants. Now Japanese barberry is considered invasive in 17 states, including Wisconsin, Minnesota, and Iowa.

Barberry changes the soil characteristics beneath the shrub in ways that make it hard for other plants to grow there. Combine that with early spring leaf-out that shades out competitors, arching stems that root wherever they touch the ground, and drought resistance, and a forest can easily be taken over by an impenetrable thicket that not even deer will eat. A barberry thicket also provides a safe, fox-resistant haven for mice, and a shady, humid home for ticks. Deer ticks feed on mice, who are reservoirs for Lyme disease.

The arching stems of barberry root wherever they touch the ground. Photo by Emily Stone. 

 

One study in Connecticut found that in an area with no barberry, about 10 ticks per acre were infected with Lyme disease. In an area with extensive barberry, that number rose to 120 infected ticks per acre. That’s not a future my parents want on their land.

Dad pulled a roll of pink flagging tape from his pocket, and marked both the bush and several trees in the area. Early the next morning, he returned to the spot with clippers and herbicide. Cutting the stems and brushing on herbicide is one of the recommended control techniques. Our family doesn’t love using herbicides, but if they are applied responsibly, they can be more effective than mechanical removal alone.

On a few hilltops where my parents have restored prairies, they use fire to keep the native plants healthy and the invasive species out. Historically, low-intensity fires might have kept this woodland healthy, too. In the absence of widespread fire, some folks have found good success at removing barberry by blasting them with the focused fire of a propane torch.

I was happy that we’d found and taken care of this one barberry bush before it spread too far and impacted the diversity and tick population of this lovely forest. November is a good time to get outside and spot the the bright red warning of barberry when everything else is gray. On the way back to the house the only other flash of red I spotted was a cardinal heading toward the bird feeders. That’s a bit of color I’m excited to see.

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 is available for pre-order from Honest Dog Books!

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.

Southward Migration

The shallow water in Northwoods marshes and bays began to crackle with a skim of ice recently, gently reminding everyone that winter is on the way. Ice-up is a firm deadline for many beings who migrate to travel at least a little bit farther south. I got caught up in the flurry of activity and soon found myself in the Mississippi River Flyway swooping around the hills and corners of the Great River Road.

The Mississippi Flyway is busy this time of year! Photo by Emily Stone.

Just south of Brownsville, Minnesota, my skyward scanning for the bald eagles, who are always plentiful here, caught the graceful, long-necked shapes of three sandhill cranes flying in formation. As they circled between the forested bluffs and weedy backwaters, I swung into the small parking lot at the Brownsville Wildlife Overlook. The rattling bugles of the cranes sent a thrill down my spine. Could these birds be some of the thousands who we saw at Crex Meadows Wildlife Area near Grantsburg, Wisconsin just a few weeks ago? The biologist there did say that the cranes start to move on when the marshes freeze.

Two cranes feeding at Crex Meadows in late October. Photo by Emily Stone. 

Evening light shimmered on the calm surface of the Mississippi River backwater below the overlook, and a big white shape caught my eye. We had watched a trumpeter swan family with one cygnet feeding in Crex Meadows before the evening of cranes, and I chuckled at such elegant birds sticking their heads in the muck to feed.

A swan and cygnet feeding in Crex Meadows. Photo by Emily Stone.

But as I watched this big white bird foraging by repeatedly dipping a long orange bill in the shallow water, waggling it around, then tipping the pouched bill up to swallow, I realized that my first glance had been wrong. Pelican! American white pelicans forage in shallow water similar to the swans, but while swans eat aquatic plants, pelicans scoop up small fish and crustaceans in their pouch, then let the water drain before swallowing everything whole. Pelicans are known for nesting, migrating, and fishing in big flocks, but this migrating bird was solo. Where were their friends and family?

A white pelican feeds alone in the backwaters of the Mississippi River. Photo by Emily Stone.

My family was waiting for me to arrive in Northeast Iowa, so I left the rest of the cacophony of waterfowl, unidentifiable in the fading light, and continued south.

After supper we stepped outside into a crystal-clear night and found the sky aglow with northern lights. Red and white curtains shifted slowly above the tops of trees on our North Ridge. When we are south of the Auroral Oval, we only see the sides of those faint curtains of light on the northern horizon. When the oval widens or shifts far enough south, the light curtains appear straight above us, and you can look up at the bottom of the curtains instead of at their side. Then, the corona appears. After a few games of Bananagrams, we looked again, and this time we found streaks of light swirling around the top of the sky. The Auroral Oval had migrated south, too.

Looking south over my parents' house at the Northern Lights, you can just barely make out the old basketball hoop on our garage in Northeast Iowa...Photo by Emily Stone.

Thanks to the early sunsets and late sunrises this time of year, I wasn’t even tired when dawn light streamed through my window the next morning. Movement in the prairie grass caught my eye, and I watched in amusement as a dark-eyed junco fluttered up to grab the middle of a grass stalk, bending it toward the ground. The little bird then slid down toward the seedhead and pecked at a few bites of breakfast before jumping off and disappearing into the thicket.

Dark-eyed juncos breed across Canada. The northern forests of Wisconsin and Minnesota are at the southern edge of their mid-continent breeding habitat, and the Northwoods sometimes see a few juncos through the summer. The real influx comes when the leaves begin to fall and juncos head south to their winter range. The big push seems to have come and gone in the Northwoods, but now I’ve followed them south.

Later, as Mom and I drove along a winding, treeless, Driftless Area ridge, we spotted a hawk hovering over the corn stubble, their face to the wind. Black patches on the bird’s wrists and belly gave away their identity as a rough-legged hawk. After spending the summer on the arctic tundra, these beautiful birds head south to hunt in open country.

Back at home, we tackled some of the projects I’d come home to help with. Organizing bookshelves, I found my parents’ well-loved set of books by Sigurd Olson, one of the best-known authors to ever capture the Northwoods in words. In a roundabout way, these books are the reason I now live Up North. I often wish it was easier for my parents to visit the lakes and forests that Olson wrote about and I’ve fallen in love with, but this trip was a good reminder that pieces of the Northwoods also come south to visit them.

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 3is available for pre-order from Honest Dog Books!

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.

Dowsing for Witch-hazel

Wet autumn leaves drifting among rugged chunks of hard gray quartzite on the trails at Rib Mountain State Park in Wausau, Wisconsin, forced my attention to my feet as I hiked. Even with trekking poles, this was no place to daydream. As I circled the top of the ridge of erosion-resistant, two-billion-year-old rock, an overlook beckoned as a place where I could pause and look up.

View from the Red Trail at Rib Mountain State Park in Wausau, WI.

The scarlet leaves of sumac shrubs framed the view, and beyond them was a spectacular sea of yellows, oranges, greens, and rich brown autumn trees in peak color. While the fluffy gray clouds had sprinkled on me a few times, the way they focused sunlight on the valley made me glad they were there.

Continuing on, with my hat brim pulled low against the sun showers, a shape on the path tripped my subconscious and, like a toddler’s toy, the shape fit perfectly into a matching spot in my botany brain. The unusual leaf was broadly oval with wavy margins and an asymmetrical base where it met the stem. I’d been admiring the vibrant reds and yellows of maple leaves, but the rich yellow surface of this leaf was already mottled with brown.

Before my conscious brain could even get involved and dig a name out from the files, I looked up. Sure enough, there beside the trail stood a spreading shrub with a few rays of sunlight illuminating tiny yellow flowers that looked just like sunbursts themselves. Witch-hazel! The flower-dappled shrub twinkled like a reminder of spring.

With flowers that begin blooming in October, and sometimes persist into December, this native shrub was a delightful find on my fall hike. As I leaned in to take photos, I also inhaled deeply. I’d read that witch-hazel has a strong smell to attract pollinators. Since scent molecules have a harder time traveling in cold air, the flowers may have to put forth extra effort to be noticed this time of year. All I detected was the distinctive aroma of wet leaves. Of course, I don’t have giant, feathery antenna like one of the flower’s pollinators.

Since many insects don’t survive the first frosts and aren’t able to fly in cold weather, it’s not obvious who might help this plant move pollen and fertilize seeds. In 1987, though, ecologist Bernd Heinrich observed owlet moths visiting the flowers. Bernd is a Professor Emeritus at the University of Vermont, and was still teaching a week-long Winter Ecology course when I was a graduate student there in 2009. We didn’t see any witch-hazel in bloom among the deep January drifts, but Bernd’s ability to notice small, odd, and interesting things in the woods is unmatched.

Owlet moths are active at night. They can shiver to raise the temperature of their thorax to 86 degrees above the air, even when the outside temperature is slightly below freezing. The thick fuzz that covers their body helps to hold in that heat just like your favorite sweater. Moth antennae are famous for detecting scents at low concentrations, so maybe they can smell the flowers even though I can’t.

A more recent study found that a few flies and small bees also visit witch-hazel flowers, and are pretty effective at moving around the sticky grains of pollen. Fungus gnats are out and about, too, but these mosquito-sized beings are probably too small to be useful pollinators. All of these visitors may be rewarded with tiny drops of nectar offered by the flower.

Once the four ribbon-like yellow petals fall, the four-lobed calyx remains on the twig all winter and looks itself like a tiny flower. The fruit doesn’t develop until the following year. I found a few of the small, round seed pods initiated by last year’s pollination nestled among this year’s flowers. They were still unripe, but I split one open with a fingernail to see the two brown seeds tucked inside. Once the seeds do ripen, the capsule will split explosively and send the seeds flying up to 30 feet away! Then the seeds spend another year in the duff before they germinate. This plant has patience!

Witch-hazel flowers from this year and fruits pollinated last year occur on the shrubs at the same time. Photo by Emily Stone. 

These two seeds would have exploded forcefully out of the seed pod and flown up to 30 feet if I'd left them on the plant to mature. Photo by Emily Stone. 

I’ve needed patience to find this plant, too. While they are common in the southern two-thirds of Wisconsin, that’s not where I spend most of my time. Up north here, they are much rarer. And where I first met witch-hazel near Sandstone, Minnesota, they are listed as a threatened species. We are simply on the western edge of their range.

While they do bloom near Halloween, witch-hazel’s name is probably a misspelling of old English words wicke or wych that meant “lively” and “to bend.” They refer to the use of a forked branch of witch-hazel as a dowsing rod, which purportedly would bend downward to point out a good location to dig a well. Hazel likely refers to this plant’s resemblance to American hazelnut or beaked hazel shrubs. Since they aren’t closely related, I prefer to hyphenate witch-hazel to indicate they are not a true hazel species. Witch-hazels are more related to gooseberries!

In a bit of reverse-dowsing, rain showers helped me see the leaf, and sun rays helped me see the witch-hazel. On that fall day, I found a deep well of beauty.

I'd never been to Rib Mountain before, but it was absolutely beautiful on this damp, fall day. 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. Natural Connections 3 is available for pre-order from Honest Dog Books!

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.

Watching Cranes at Crex Meadows

“Turn here, they’re heading north!” I directed my fiancé as we navigated the gravel roads of Crex Meadows Wildlife Area near Grantsburg, WI. We’d spotted a line of sandhill cranes flying through the sunset sky, and were following them toward what we hoped would be a spectacular evening of birdwatching.

Thousands of sandhill cranes converge near this wetland complex each fall. They spend their days fueling up for migration by gleaning waste grain from recently harvested corn and soybean fields nearby. Then, at dusk they rise from the fields and stream into the wetlands. By roosting together in shallow water, the cranes make it harder for their numerous possible land predators, like coyotes, wolves, bobcats, and fishers to sneak up.

As we puttered along the grid of gravel roads trying to triangulate the most likely landing area for the flock, I felt like I was reliving my childhood of being on the chase crew for my grandpa’s hot air balloon in central Iowa. The difference was that Grandpa could communicate his plan to us through the radio in the old farm truck, and he was aiming for an accessible landing pad.

Balloons don't ALWAYS land in an accessible place...Photo by Larry Stone. 

These cranes had no concern for our viewing access. At the Crex Education and Visitors Center, we’d been warned that a recent influx of visitors had spooked the cranes away from some of their usual, easy-to-see roosts. Even when people are quiet, stay in their cars, and stay out of the wetlands, the birds may choose to go elsewhere. Luckily, this extensive wetland complex has plenty of space away from roads where the cranes could go to get some privacy.

That ability to hide makes it hard to keep track of their numbers. A few days after our visit, on October 29, the Wisconsin DNR conducted the annual survey of the crane population. Eleven staff spread out among known roost locations in Crex and the nearby Fish Lake Wildlife Area. Arriving before dawn, they prepared to witness the early morning commute of cranes from their bedrooms back to their breakfast fields.

Some cranes stay right in Crex Meadows and feed there throughout the day. This family to two adults and one juvenile crane were spotted earlier that afternoon. The second adult is feeding with their head down and is quite invisible in this photo. You can tell the adults by their red head, and the juvenile by the lack of it. 

“The total count with Crex and Fish Lake was 7,754 cranes,” reported DNR wildlife biologist Joe Dittrich when I called him up the day after the survey. In contrast, the average over the last three years was 13-14,000. That’s a sharp decline. Dittrich wasn’t too worried about the numbers, though. The morning of the count had been extremely foggy, especially at the Fish Lake unit, with visibility of only 100 yards. He suspects that they missed about half of the birds there. It’s also possible that some birds have already continued on south to their winter habitat in southern Georgia and Central Florida. No banding or telemetry efforts have established more specific migration routes or schedules for the birds who pass through here.

Even if some of the birds have left, Dittrich assured me that a good number of them will likely stick around until the wetlands begin to freeze up during the day. With the warm fall we’ve been having, that might mean we have several more weeks to witness this phenomenon. The Crex Visitor Center is happy to provide current information if you call 715-463-CREX.

“I really like their calls,” Dittrich told me when I asked what he liked best about the cranes. That’s no surprise. Many of us have heard one or two cranes give their thrilling, rattling, bugles during spring migration or nesting season. The cacophony of hundreds or thousands of these ancient voices echoing across the sunset is unforgettable.

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

That isn’t mere hyperbole. Cranes are some of the oldest living birds. In Nebraska, a 15-million-year-old crane skeleton records their ancient stake on the territory. Over that time scale, the habitat has changed more than the bird. Several glaciers advanced and retreated. The last one here in Wisconsin sent a flood of sandy outwash southwest from the Bayfield Peninsula, creating the Northwest Sands Ecological Landscape. Then a rogue, northeast-flowing section of ice dammed up some of the meltwater, which created Glacial Lake Grantsburg. The lake’s calm water accumulated clay sediment. Together, the patchwork of sands and clays, along with science-based wildlife management, has turned this area into a destination for nature lovers of all kinds.

The Northwest Sands mostly failed at farming, and now host lots of important wildlife areas! Source

FIGURE 6. Advance of the Grantsburg Sublobe, an offshoot of the Des Moines Lobe, overriding the St. Croix Moraine blocking southward drainage of the Mississippi River, and forming glacial Lake Grantsburg.  Source

And yes, I was thinking about the glaciers as we stood at the edge of the wetland watching the flocks of cranes appear on the horizon, stream in over our heads, and descend with legs dangling into the water we knew was hiding behind grasses and shrubs. That old ice is the reason the cranes are here, and this winter’s ice is the reason they will leave. In between, their rattling cries send an awestruck shiver down my spine.

I took this video on October 14, when the cranes were still landing just north of Main Dike Road. Spectacular! Turn up your volume! 

 

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 is almost here!

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.

Fantastic Fungi

The air shimmered as I walked through the forest, the heavy mists encompassing me in a damp blanket. As my shoes trod on soggy leaves, I took in the quiet serenity of the forest. Many of the trees had begun their annual changing of the colors, painting the canopy in shades of yellow, orange, red and green. Their discarded leaves were already beginning to dot the forest floor in late September. But fallen leaves weren’t the only contributors of color on the ground–the fall mushrooms were popping in the Northwoods.

A bright splotch of red and orange drew my gaze downwards, where a species of waxy cap mushroom was growing among the green blanket of moss. They are characterized by being very colorful, with a shiny, waxy looking cap, and thick gills. And unlike many other mushroom species, they are not mycorrhizal or saprobic. This means they don’t obtain their nutrients through extensive networks of mycelium that form a symbiotic relationship with plant roots, or obtain nutrients from decaying wood and organic matter like saprobic mushrooms. Waxy cap mushrooms are biotrophic, forming a symbiotic relationship with the roots of grasses and forbs, as well as the rhizoids of mosses, obtaining nutrients from them.

A brightly colored waxy cap mushroom growing up from the forest floor. 

Many other mushroom species inhabited the forest, making it come alive with fungi. Saprobic fungi in particular were very prevalent. Resinous polypores clung to decomposing trees, making it seem like the trees were growing pancakes dotted with maple syrup from their bark. Tiny Marasmius mushrooms sprouted from the top of a mossy log, their spindly brown stems and grooved white caps made my imagination run with thoughts of them being used as umbrellas by small woodland invertebrates. And even while my imagination ran wild with these fun fungi appearances, I was appreciative of the ecological role they play within the forest. As saprobes, they were breaking down the wood they inhabited and recycling important nutrients back into the soil.

Resinous polypores on a decaying log. 

But the wealth of different mushrooms carried with it many different feeding styles and ecological relationships. One complex and interesting ecological relationship that can be found in the Northwoods is between Entoloma abortivum mushrooms and honey mushrooms in the Armillaria genus. These fungi can be found grouped together in forests, and though they have an inconspicuous appearance, they are waging war beneath the soil. One of these mushrooms is parasitizing the other, disrupting the development of the other’s fruiting body and prohibiting them from reproducing.

Honey mushrooms in the Armillaria genus, have a brilliantly nefarious adaptation in regard to how they obtain their nutrients. They are both saprobic and parasitic. They infect their host, sapping its nutrients and eventually contribute to its death. Typically, this is the end of a parasite's ability to get nutrients from its host. However, since honey mushrooms are also saprobic, they continue to derive nutrients from their now dead host tree by breaking down the wood, and decaying the tree. This capability is called necrotrophism.

The other half of this fungal relationship, the Entoloma abortivum, are light grey, plain looking mushrooms that are typically found near decaying wood. While this mushroom's dull appearance may seem like a barrier to identification, Entoloma abortivum can at times provide a hint to its identity in the form of a lumpy, mass of white fungal tissue near the Entoloma’s fruiting body. This odd looking fungal body was originally thought to be an “aborted” form of the Entoloma, caused by a parasitic attack on the Entoloma as it was beginning to fruit.

Because honey mushrooms are parasitic, and are often found fruiting in the vicinity of the Entolomas, they were originally thought to be the aggressor in the Entoloma vs honey mushroom war. However, in 2001 a scientific study by Czederpiltz, Volk and Burdsall found the opposite to be true. They found that the “aborted” Entoloma were actually deformed honey mushrooms that were attacked by Entoloma abortivum hyphae– showing that the Entoloma is the parasite, not the honey mushroom! Since the parasitic attack happens underneath the soil, and involves both mushrooms' complex network of mycelium, there are times where the fruiting body of the honey mushrooms are not found near the Entolomas. But, with the presence of the “abortive entoloma”, we know that the honey mushroom mycelium is underneath the soil, but was parasitized by the Entoloma before it could fully fruit.

Entoloma abortivum and the "abortive entoloma".

It is amazing to me that a simple walk through the forest to see fall mushrooms can reveal so many ecological connections taking place. From stepping on soil that hides a vast network of mycelium, stretching out through the soil to obtain nutrients– to passing by a decomposing tree littered with saprobic mushrooms, slowly breaking the tree down and returning it to the soil. One can always find something to marvel at in the Northwoods, especially in the fall.

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.

Butterfly Breezes of Fall

A gentle breeze rippled the surface of Gabimichigami Lake. Paddling steadily in the bright sunshine of early afternoon, we were grateful that it wasn’t a steady wind. More than a mile of open water surrounded us with no islands or points to hide behind as we crossed from one portage to the next on our annual Boundary Waters canoe trip.

Hillsides of young aspen and birch glowed golden in the distance. At first, a flutter at the edge of my vision made me think that an autumn leaf had somehow managed to fall half a mile to the middle of the lake. A closer look revealed the dark purple wings of a mourning cloak butterfly. In late September?

I’ve often looked for mourning cloaks in early spring, knowing that these are one of a few butterflies who overwinter as adults and emerge as the snow is melting. They feed mostly on tree sap, fruit juices, and the honeydew excreted by aphids, so it’s not hard for them to find food even before most flowers bloom. They make the most of sunshine even on cold days by spreading their dark wings and body to absorb warmth.

A mourning cloak butterfly suns themselves on a paper birch tree. Photo by Emily Stone.

The adults mate and lay eggs even before the leaves of their larval host plants emerge. After the caterpillars hatch and feast on willow, aspen, birch, or a variety of other tree leaves for a couple of weeks, they form a pupa. After another couple of weeks, they emerge as adults in June or July. This seems perfectly timed to take advantage of peak flower availability, but abundant nectar doesn’t tempt them to feast. Instead, the new adults pause their development and go into a period of dormancy similar to hibernation, called estivation.

Then, in September and October they begin another active period, presumably to build energy stores before their winter round of hibernation. While mourning cloaks aren’t considered migratory, there’s some evidence that some individuals do migrate, perhaps to find a slightly warmer place to overwinter. Wherever they go, they’ll snuggle into hollow logs, wood piles, and loose bark. Hopefully, wherever they hibernate also gets blanketed by insulating snow and becomes part of the stable environment of the subnivean zone.

Throughout the trip, I saw at least half a dozen mourning cloaks out over the water, dancing in and out of the dappled sunlight at our campsite, and briefly landing to bask on sunny, warm rocks. Seeing them reminded me of an early spring hike up to St. Peter’s Dome, when I photographed a mourning cloak sunning themselves on a birch tree.

Mourning cloak butterflies become active in fall after a period of summer dormancy. This one photobombed a sunny afternoon on Saganaga Lake in northern Minnesota.

Photo by Emily Stone.

It’s not a bad schedule, really. Emerge into the gently warming days of spring. Take a siesta during the hottest days of July and August. Enjoy a fall feast before tucking in for the winter. They use this plan to survive across North America and even in Asia and Japan.

I even spotted one mourning cloak as recently as last week on the Superior Hiking Trail above Silver Bay, Minnesota. After watching their irregular flight until they disappeared in to the forest, a flutter at the edge of my vision caught my attention just in time to watch an autumn leaf come to rest on the ground.

Small quaking aspen leaves carpeted the trail in a mosaic of yellow and green. They were evidence of yet another way that a Lepidopteran (butterflies and moths) survives the winter. Green leaves don’t usually fall from the tree, but the trapezoids of chlorophyll captured between the first and second veins on one side of the leaves’ midribs told me all I needed to know. These were the larval home of a tiny moth.

A moth larva creates this green and gold pattern in quaking aspen leaves.

Photo by Emily Stone.

Back in July, a small, brown moth with white-fringed wings laid an egg on the leaf petiole. By September, a translucent larva hatched and bored into the leaf’s petiole, causing the stem to swell into a small gall. Munching her way up inside the leaf under the cover of darkness, the leaf-mining larva interrupted the mechanisms the tree normally uses to draw chlorophyll out of the leaf during the waning days of autumn.

Such a tiny caterpillar would dry out in the summer heat if she tried to pupate high in the tree canopy. Instead, she timed her life cycle to hitchhike on a falling leaf down to the damp forest floor. Now there, she is stealing a few more bites of the green energy she’d hoarded in the leaf. Presently she will pupate in relative safety and an agreeable microclimate. The soon-to-be-moth spends the winter in her cocoon, which is loosely woven to the surface of the now-brown leaf.

Colorful leaves and colorful wings flutter on fall breezes, all getting ready for winter.

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.

Flying Kittens

“Just hold her like this,” Kurt told me. So I carefully nestled my first two fingers into the soft, warm feathers around the neck of this tiny northern saw-whet owl, cradled her soft, warm torso in the palm of my hand, and secured her brown and white wings with my thumb and other fingers. My heart stopped for a moment, but under those soft, warm feathers I could feel her smaller heart racing.

Kurt opened the sliding door onto the deck of his cabin. I paused to snap a photo of her huge, yellow-ringed eyes staring back at me in the dim light. Then we walked out into the night. As we waited for all our eyes to adjust, I focused on the feel of this incredible being in my hand. So soft, so warm.

Mike Avara, another scientist who is recruiting volunteers for some exciting new owl research in Bayfield County, affectionally described saw-whet owls as flying kittens. Indeed, the feel of her took me back to childhood when my cousin Meggan let me, a member of a family with no pets, hold one of the several very new offspring of her barn cat. Even as a child, the experience provoked an intense sense of responsibility along with the joy of connection to another little life.

Kurt gave the go-ahead, and I opened my hand. There were a few sharp pokes of tiny talons on my palm as she took to the air, and we watched as her fluttering flight became silhouetted against the moonlit sky, then disappeared into the black of the nearby forest.

Regrouping, Kurt and I put on our jackets and headlamps to check the other set of mist nets. About the size of a volleyball net but so delicate as to be almost invisible, mist nets have been used for decades to capture small birds. Each June, our Wisconsin Master Naturalist Volunteer Training Course experiences bird banding in the Moquah Barrens with Master Bander Jim Bryce. In daylight, his nets catch chestnut-sided warblers, brown thrashers, and clay-colored sparrows. Saw-whet owls are the smallest raptor east of the Mississippi—about the size of a robin and weighing just around 90 grams—and so the same nets work for them, too.

For many decades, northern saw-whet owls were caught only incidentally when nets were placed to catch other owls or nocturnal birds, and ornithologists thought that they were rare birds. Then someone decided to play a recording of the male’s song near the nets. Captures skyrocketed! We now know that saw-whets are fairly common across their range, although like most birds they have likely declined due to habitat loss over the past decades.

In the center of his three nets, which he deploys on dry nights from the last week of September through October, Kurt has a speaker set to play the owl’s loud toot-toot-toot call over and over. This sound is easily mistaken for the back-up-beep of heavy equipment, except that the owls are often calling at a time and place where no one would be working. The nets were empty on our second check, but earlier the speaker had blasted right at us as he worked to extract the little owl from the net.

This repeated call is the source of their name, since sharpening each tooth of a saw on a whetstone results in a repetitive sound. The owls make less well-known sounds, too. While exploring a series of recordings, I came across a vocalization nicknamed the “strangled cat whine.” I’ve heard this spooky sound numerous times in dark woods, and never known that it was just a flying kitten.

The owl in the net clacked her tiny beak in dismay at her predicament, but made no other sounds. Kurt is a Master Bander who has been banding birds since 2000, so with his experience it didn’t take long for the owl to be free of the net. Once inside his cabin, Kurt quickly prepared a leg band. Issued by the USGS Bird Banding Lab, the unique number stamped into the aluminum will allow this bird to be identified throughout her life and across the entire continent if she’s ever caught again. Unfortunately, federal funding for the banding lab’s important work is at risk of being cut.

Banding birds like this saw-whet owl has provided scientists with a wealth of information over the decades. Photo by Emily Stone.

Seven to eight percent of the 350 or so saw-whet owls Kurt has handled have already been banded, by him or someone else. These recaptures are an amazing source of information about the movements, ecology, and lifespan of the birds. Even if a bird isn’t recaptured, the measurements Kurt took of the owl’s weight, wing chord length, and age provide valuable data. This owl’s wing chord length of 136 mm, paired with a heavier weight, is what told us she was female. Male raptors tend to be smaller.

We also shone a UV light on the underside of her wing, where fresh feathers glowed hot pink. As feathers age, the UV-reactive pigment degrades, and older feathers look faded. This little owl was hatched just last spring and had only recently molted all her juvenile plumage into adult feathers, so they all glowed brightly.

Band-new feathers on this underside of the wings of this young saw-whet owl reflect lots of ultraviolet light. Photo by Emily Stone.

By this time next year she’ll have some bright and some faded feathers. Maybe Kurt will find her in his nets again. Maybe Mike Avara will discover that she’s raising chicks in one of his nest boxes. No matter what, her few minutes of discomfort at the banding station will help us understand more about her entire adorable species and what we can do to help them navigate a changing world.

Learn more about the volunteer opportunities with Mike and Kurt's saw-whet owl nest box and MOTUS tower research on the Museum's iVolunteer page: https://cablenhm.ivolunteer.com/saw-whet-owl-research

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.

Green Frogs Prepare for Winter

Golden birch leaves glittered across the portage trail as we pulled our canoe up at the landing. My paddling partner and I inhaled deeply of warm afternoon air that was sweetly scented with fall. Hoisting the canoe onto my shoulders, I started off down the trail. It went downhill from there, and not the good kind of downhill.

 

Off the end of a rotten boardwalk we found more mud...

One stretch the portage trail was an old railroad bed and actually quite nice to walk on!

First was the huge patch of sticky mud that sucked at my muck boots and threatened to throw me off balance. A puddle of unknown depth hid slippery rocks beneath the murky water. The next wet patch was spanned by a boardwalk, but the single plank was narrow, slimy, and bounced like a teetertotter where supports had become unstable. Finally, within sight of the next lake, movement near the toe of my boot startled me almost to the point of disaster.

 

Beaver-flooded portage landing.

Big black eyes with golden rims stared up at me from the slope of a rock. Crooked toes gripped the rough surface, and long hind legs braced for a quick escape. The green frog who had jumped out from underneath my boot perched motionless, as if that made them invisible.

 

Looking closer, I was captivated by the coppery shine of their skin, with indistinct dark spots. Despite their name, just a swath around their smile was green, like a smear of Halloween lipstick. Many frogs shift their skin to a darker color on cool days to absorb more warmth from the Sun, which is one reason green frogs (Lithobates clamitans) in the north are often brown.

From their large size, I guessed that this frog was female. Looking back on photos, I could confirm this by the comparing the size of her tympanum—the external ear structure—to the size of her eye. They were roughly equal in diameter. This membrane transmits sound waves to the inner ear. Male green frogs’ tympanums are larger than their eyes, although scientists aren’t sure what benefit that provides.

 

Female green frogs have a circular ear patch called a tympanum that it about the same diameter as their eye. On males, the tympanum is bigger. Photo By Emily Stone.

Throughout the trip—six muddy portages, five lakes, and then back again—we spotted gobs of green frogs at the landings leading into shallow, weedy water, and no frogs at the graveled landings with clear water. Green frogs feed by sitting and waiting for anything large enough to see and small enough swallow. Mud and plants make great habitat for these creepy crawlies, and therefore great habitat for frogs, who also lay their eggs among emergent vegetation.

While we reveled in the pleasantly warm weather, the golden birch leaves on the ground and orange-tinged cedar boughs along the shoreline were a constant reminder that winter is on the way. At home, I’ve been hearing lonely spring peepers call loudly before dawn every morning, from just outside my open windows. Like wood frogs, spring peepers spend the winter just beneath the forest’s leaf litter frozen solid. They are one of the first to wake up and thaw out come spring.

Green frogs can’t tolerate being frozen, and so must find a place to overwinter where they are guaranteed to stay liquid. Often this is simply at the bottom of a wetland or pond. They slow their metabolism and absorb a little oxygen through their skin. Sometimes they take a cue from their cousins and nestle into lake-bottom leaf litter, which gives off a little bit of warmth as it decomposes.

While spring peepers must wake up in a hurry, call like crazy, then rush to lay eggs in woodland pools that eventually dry up, green frogs can take breeding season at a more leisurely pace. Lakes sometimes take a while to thaw. Then the large mass of water takes even longer to warm up. Throughout it all, green frogs don’t have to worry about their eggs or tadpoles drying out before hopping away, even though they don’t start making their banjo-like plunk calls to attract mates until the peepers are almost done.

In fact, green frogs sometimes overwinter as tadpoles, and might not metamorphose until their second summer. By altering the composition of their muscle membranes, the tadpoles maintain their ability to put on a burst of evasive speed even in cold water. This helps them escape predators without wasting energy by moving quickly all the time. Dragonfly nymphs, diving beetle larvae, and water scorpions are all predators who also survive winter under the ice.

My canoe paddle bumped the bottom on one super shallow lake, and I started to worry. What would happen to the frogs and all those beings if this tiny water body froze to the bottom? I later read that green frogs have been observed gathering around springs where groundwater bubbling up will stay at a steady, unfrozen, temperature throughout the winter. They must be good at finding other warm microhabitats, too.

One last green frog watched from a wet rock as we paddled up to the final portage landing. Even more golden birch leaves had fallen overnight, and a lonely migrating loon wailed a farewell from across the water. Each of us was preparing for winter in our own way.

 

Getting out on as many paddling trips as possible before ice up is our way of preparing for winter!

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.