Thursday, March 23, 2023

Facebook Post and Frog Phenology

A Facebook notification popped up on my phone screen and I tapped it absentmindedly, mostly to make it go away. Even as the post was loading, sound erupted. Wood frogs quacked, chorus frogs crrreeked, spring peepers peeped, leopard frogs snored, toads and tree frogs trilled, green frogs plunked, and finally bullfrogs hummed.

I grinned as I scrambled to turn down the volume. The animation continued without sound—a dark blue line moving to the right across a bar graph showing which Northwoods frogs sing in each month from March through August.

I created this audio and animation in the spring of 2020 while working from home. I thought it was a sad replacement for the in-person version of a frog call chorus I should have been teaching in first grade classrooms during MuseumMobile visits.

And yet, the post went viral.

From all over the country and the world, people who were spending more time at home, and outside, and with less traffic noise, heard the frogs and were eager to identify their newly noticed neighbors. They liked and shared the post, commenting about what they were hearing in their own backyard, how the audio had startled their dog, and what beautiful memories the frog songs revealed.

Each spring since 2020, the start of real frogs calling inspires people to begin sharing the post again. By this point, the post has a reach of more than 9.5 million. Just a few days ago, the phenomenon began again—which is what prompted the notification and sound erupting from my phone!

The steady stream of new comments the post is receiving is a little disheartening, actually. Those people are hearing frogs already! A commenter from southern Missouri wrote that their daffodils are almost finished, lilac buds are close to bursting, and sugaring season is long over.

Meanwhile, my daffodils are under a mountain of a plow pile. Last year they didn’t even get uncovered soon enough to bloom. The yardstick I stuck in the snow near my subnivean thermometer tells me that we still have 30 inches on the ground. Snow continues to be in the forecast. Temperatures will plummet into the single digits tonight.

Is it wrong to yearn for daffodils in March?

I don’t remember those feelings as a kid. The seasons progressed happily from sledding to mud pies to dandelion soup, and I had little awareness that other places experienced seasons differently. With the advent of social media, I now see images of crocuses, salamanders, sunshine, and gardening slide through my feed while I look forlornly out on snow.

We call some of the negative emotions triggered by social media the “fear of missing out (FoMO).” In 2013, British psychologists Przybylski et. al. defined FoMO as the “pervasive apprehension that others might be having rewarding experiences from which one is absent.” Most people apply the feelings to social connection, but in the Northwoods, I think FoMo should also be applied to weather.

Of course, we will experience spring eventually. And the annual arrival of spring—as it creeps up from the south—brings with it many phenological observations. Phenology is the study of when specific events happen in nature from year to year in a specific place. When do daffodils bloom? That answer will be different for each latitude, each yard, and even each side of the same house. (The south-facing side warms up faster, of course!) The answer will also differ based on the weather of that particular year.

Using my Facebook feed, I can compare the arrival of spring here to the arrival of spring around the country. Websites like let us seek out that same information in a more organized way. They curate maps that show the arrival of robins, hummingbirds, monarch butterflies, loons, and more as they migrate back for the summer.

While the frog call animation that started my reflection on phenology indicates that we could hear wood frogs as early as the end of March, I expect that spring will be late.

Luckily, the frog call chorus already arrived at a first grade classroom near you! First the kids learned to imitate several frog sounds. Then I assigned each row of students to be a particular species. Finally, I directed the students in a full season of frog songs.

“Wood frogs begin, with peepers close behind. They keep going while leopard frogs start! Then the wood frogs and peepers stop. Bullfrogs begin. Leopard frogs go quiet, and finally in August all we’re left with are the bullfrogs. Hmm…Hmm…Hmm…Until even they are silenced by fall.” Snow comes, and we start the whole cycle over again.

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

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum is closed for construction of our new exhibit: The Northwoods ROCKS! It will open on May 2, 2023. Follow us on Facebook, Instagram, YouTube, and to see what we are up to.

Thursday, March 16, 2023

MORE Bear Babies

My feet were just starting to get numb from standing on the snow-packed trail when the activity over by the den changed. Students with University of Wisconsin Stevens Point’s (UWSP) Wisconsin Black Bear Project, led by Dr. Cady Sartini, plus several other wildlife professionals, were working together around the mouth of the den.

A student broke away from the group and headed to where we non-researchers were stationed out of the way. Abby was cradling something small against her chest, and the adoring smile that lit up her face gave it away: she was carrying a bear cub.

Abby, a University of Wisconsin Stevens Point’s Wisconsin Black Bear Project student researcher, snuggles a tiny black bear cub to help keep him warm while his mother is anesthetized and other researchers collect data on her. Photo by Emily Stone.

Eager hands reached out to take the cub and nestle him into a puffy winter coat. Soon more students with more cubs headed our way. Four tiny cubs were distributed among the willing volunteers. Mama bear lay anesthetized in the den, and the cubs needed our warmth.

Back in January, Dr. Sartini allowed a group of Wisconsin Master Naturalists to join her team on a reconnaissance mission to find out if this den had cubs, yearlings, or just the collared adult. As I wrote, we saw the mom’s sleepy face, and heard the grunts of two cubs. Two cubs were all I’d been expecting when I lucked into joining Dr. Sartini and her students on this data collection visit to the same den.

One of the students held a cub out toward me, and I cradled him against my chest, trying to tuck him inside my puffy coat while his long claws tangled in nylon and wool. I’d forgotten to take my hood down, and soon the anxious cub was climbing up my neck, needle-sharp claws poking and wet nose nuzzling. It was adorable, funny, and painful all at once. Climbing trees to safety is a life-saving instinct in bear cubs, and although this was the first time outside their den, their long, sharp claws were ready to go!

Kris Dew, bear project supporter, shows off the adorable feet of a cub. Photo by Emily Stone. 

Startled by the cub’s climbing, and unable to untangle him alone, I enlisted Laura Schulte, a Milwaukee Journal Sentinel reporter also covering the event, to help. Together, we got the cub off my neck and swaddled against her chest so that he was comfortable enough to stay put—although the little guy whined the entire time. Later, we discovered he was the runt of the litter at only 3.4 pounds to his brothers’ 4. They’ve likely quadrupled in size since birth just over a month ago.

A few minutes later, someone shared their cub with me. Paul Smith, a Milwaukee Journal Sentinel outdoor writer who has been covering this project for 30 years, helped me get the cub settled comfortably and remarked on just how perfect the little ones are. Paul will be writing about the 45-year history of this long-term research project.

You can barely see him against my gray sweater, but there is a little cub snuggled up in my coat! 

Taking off a mitten, I reveled in the softness and warmth of this tiny wild creature, and soon he became so quiet that I’m pretty sure he was sleeping. I felt honored by his trust. Despite bears’ excellent sense of smell, there’s no evidence that a mama bear will abandon her cubs if she catches a whiff of human. And despite rumors of animal babies being scentless, this cub had plenty of his own odor.

Disrupting a den like this is undoubtedly stressful for both mother and cubs, which is why protocols and safety measures are in place. But in the 45 years that the Wisconsin Black Bear Project has been collecting data and handling cubs, the impacts have been found to be minimal. And the data gathered has proven essential for learning about and managing black bears in Wisconsin, and training students in wildlife research.

After a few minutes, Abby and a volunteer weighed each of the cubs by placing them into a cozy stocking hat and attaching a spring scale through the knit. They were sexed (all boys) and students held a ruler up to the hair between their ears—a proxy for age. Then a wildlife biologist collected nasal and blood samples to screen for wildlife diseases.

Abby, a University of Wisconsin Stevens Point’s Wisconsin Black Bear Project student researcher, weighs a black bear cub. The cub is placed in stocking hat to keep him warm during the process. Photo by Emily Stone.

Measuring the hair of a bear cub to estimate age. Photo by Emily Stone

Meanwhile, back at the den, students and professionals struggled to get the limp, heavy female out of the ground. The entrance, tucked under the roots of a spruce tree, proved too narrow. She couldn’t be weighed or fully measured. With just her head out, they checked her collar, took vitals, and collected a tooth. Bear teeth record growth rings just like a tree. A cross section can tell researchers her age, and even record the years she gave birth and had less calcium to spare.

At the end of the day, the cubs were safely returned to the den with a drowsy mother, and the den entrance covered with balsam boughs. Researchers packed up samples and data for analyzing in the lab.

“It didn’t go the way we thought it would go,” said Dr. Sartini as we stuffed gear into vehicles, “but it went just fine. So many of the skills the students gain here will be transferable. Risk management, teamwork, and planning are useful for studying other wildlife and doing any kind of science.” John Tracey, the wildlife vet in charge of anesthetizing the bear, agreed, “As much as you want an event you’re running to go smoothly, it’s also beneficial for the students to see curveballs and challenges come up and get dealt with calmly.”

Researchers are always looking for new bears to add to the UWSP Wisconsin Black Bear Project, so if you know of a bear den in Ashland, Bayfield, Price, or Sawyer Counties, you can contact Dr. Sartini directly at Dens outside this area can be reported to your nearest DNR office for their statewide research project.

Want to learn more? Dr. Cady Sartini is giving a live/virtual lecture on March 16: “The Wisconsin Black Bear Project: Celebrating 45 Years of Bears in the North Woods.” The lecture is part of the UWSP College of Natural Resources Spring Seminar Series.

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

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Growing Up WILD exhibit will close on March 15, and The Northwoods ROCKS will open on May 2, 2023. Follow us on Facebook, Instagram, YouTube, and to see what we are up to.

Thursday, March 9, 2023

Snowshoe Field Trip

Thick clouds of snowflakes swirled as I climbed the steep hill. Behind me, a string of 20 third graders from Hayward Intermediate School padded along on the Cable Natural History Museum’s rental snowshoes. Their feet were quieter than usual—in many years the trails are hard-packed ice by the time we embark on this annual field trip. This year, fresh snow dampened the crunch of plastic and metal.

The students themselves were just as talkative as ever. Barely out of sight of the big yellow school bus, they’d started in with the cries of “I’m tired! I’m hungry! Are we there yet?” By age 9, they were already finding humor in what they knew to be cliché’ (even if that word has yet to appear on a spelling test).

When the upper branches of a freshly fallen tree appeared ahead of us, I took quick stock of the options. “Are you ready for an adventure?” I asked, and led the students through fresh snow, up a steep bank, onto the high angle of the hillside above the trail, and then back down. “Yes! More adventure!” cried the eager ones at the front of the line. While the less adventurous ones struggled with the hill, I texted Rich Jaworski, the new director of the Museum. By the time we passed that way again, the tree had magically disappeared, even the sawdust covered by snow.

This field trip is designed around the Mammal Tour at the North End Trailhead, a roughly 1-mile loop trail where we’ve placed life-size metal silhouettes of 25 Wisconsin mammals. But when we got to the start of the main loop, the first metal animal was nowhere to be seen. I gingerly stepped around the mound where I thought it should be, but no badger appeared. Forging ahead without the visual aid, I asked, “What are badgers really good at?” “Basketball and football!” was the response. Digging dens is what I’d been thinking.

The woodchuck and chipmunk were also deeply buried by crusty layers of snow and ice. But the wolf’s nose was howling out of a drift, and not far away the deer’s antlers beckoned, too. At the trailhead, I’d given two students backpacks to carry, and now their jaws dropped as I pulled a full, fluffy wolf pelt from one of the packs.

After petting the fur, we talked about how wolves’ big feet help them stay on top of the snow, especially crusty spring snow. In contrast, deer’s sharp hooves—well suited for running quietly and efficiently through the leaf litter—punch through the crust and allow their owner to be caught.

There was no crust on this day. The snow fell so fast that our tracks were obscured by the time we completed the loop less than two hours later. And the talk of venison for a wolf’s dinner must have made some kids hungry, because they scooped up big handfuls of fresh snow and ate messily. “Just so you can make an informed decision,” I told them, “every single snowflake has a piece of dust or bacteria at its center.” No one was deterred.

On the second morning (it takes four rounds to get 102 third graders out on trail!) sunshine beamed down instead of snow. Just before the corner of the missing badger, tiny tracks quilted the drifts. Mice had darted from tree to tree in last night’s moonlight. I couldn’t resist pointing them out. “Who made these?” I asked the kids. “Deer! Fox! Rabbit! Squirrel!” they shouted, clearly not computing that the track-maker’s feet were less than half an inch long.

“All winter,” I told them, “mice live in a magical space where snow and ground come together.” “I know what it’s called!” yelled a kid from the back of the line. “So,” I continued, “when you look out in the woods and see this blank snow, you can also imagine entire mouse cities and civilizations hidden underneath, where they are eating, sleeping, fighting, playing, and having babies all winter long. This magical place is called…” and I gestured to the kid…”The subnivean zone!” he yelled proudly. “I learned that from Wild Kratts” he added.

The mice often use the base of a tree as a gateway between the subnivean zone and the surface, I explained, but sometimes they just burrow straight into the snow. With eyes alert as we hiked, these portal holes appeared everywhere.

Back at the corner of the missing badger, we recapped. “Today we learned about things that animals have and do that help them survive the winter. And we put some adaptations on ourselves, too. What adaptations am I talking about?” I asked. “Snowshoes!” they yelled. And then we tromped down the hill to take them off.

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

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Growing Up WILD exhibit will close on March 15, and The Northwoods ROCKS will open on May 2, 2023. Follow us on Facebook, Instagram, YouTube, and to see what we are up to.

Thursday, March 2, 2023

Visiting Glaciers in Alaska and Wisconsin

It was just a diagram on my screen, but the carefully drawn cross-section of a glacier with kettles, kames, and eskers being revealed as the ice melted drew me in like a treasure map. Then, lost in thought, I stared past my computer screen to the snow-covered hills, valleys, and lake surrounding my home. The diagram had come to life.

As I work with a committee to design and build our new exhibit “The Northwoods ROCKS! Where Geology is the Foundation for Fun,” (opening in May!) I have geology on the brain. Thinking about the glaciers that once covered Northern Wisconsin also has me reminiscing about walking on and paddling next to modern glaciers during my four-month trip to Alaska in the summer of 2018.

Exit Glacier: Kenai Fjords National Park

At the Marmot Meadows overlook we began to descend out of a lush field of wildflowers and straight down a rocky trail toward the white, blue, and brown wrinkles of the glacier.

The glacier’s surface was a gracefully sculpted expanse of luminous snow and ice, sprinkled liberally with brown dirt. Rivulets of water cut narrow ravines through the dirty surface and created small, white-walled canyons with intensely blue bottoms. Those small ravines probably flowed along the tracks of healed crevasses.

Our guide led us to the edge of a moulin. He held onto my harness, and I peered into the cavity. Water may have excavated this roughly circular, well-like shaft out of an old crevasse or found some other weakness in the ice. Either way, I watched a tiny stream glide over the surface and then cascade into the smooth, spiraling hole.

Moulins play an important role in carrying water and sediment from the surface of the glacier into its depths. Mount Telemark, a 380-foot-tall old ski hill in Northern Wisconsin, was probably built by water-born sediment that poured into a large moulin 14,000 years ago at the end of the continental glaciation. I was thrilled to see a much smaller version of this glacial feature in action.

Exit Glacier in Kenai Fjords National Park, Alaska, was the first glacier I ever walked on. At home in Wisconsin, though, I walk—and ski, bike, run, hike, and paddle—on the results of glaciers every single day. Photo by Emily Stone

A moulin (hole) in Exit Glacier.

Aialik Glacier: Kenai Fjords National Park

After a water taxi ride from the town of Seward southwest to another fjord, the group switched to kayaks and glided through a maze of mini-bergs. A half-mile from the glacier’s front we paused, admiring the huge, pale-blue tongue of ice that reached down out of the clouds and into the sea.

Suddenly, thunder rumbled. A little bubble of excitement rose in my chest. I love thunderstorms, and I’ve missed them while in Alaska. This was even better. The ice itself was rumbling. We watched a chunk of ice tumble into the sea. A small white avalanche of crushed ice poured in behind it, and a wave spread out from the glacier. We gasped and cheered.

Valdez Glacial Lake: Valdez, AK

We launched inflatable kayaks onto mirror-calm water in a dense fog. Huge icebergs loomed in the shallows. Someone made a joke about the Titanic, but that didn’t stop us from paddling up for a closer look. Most bergs were heaped with blankets and piles of wet, brown sediments, which indicated that they were floating upright, in the same orientation as when they’d been attached to the glacier. Where chunks had broken off to reveal their inner ice, though, the crystals were huge, sparkling, and made luminous patterns of white and blue.

After lunch, the fog burned off and revealed a brilliant blue sky. We scrambled up a canyon wall to get a better look at the glacier itself. The brown-and-white striped river of ice flowed from around a corner and into view. At the terminus lay a jumble of broken, dirty ice chunks, in the process of detaching fully into the lake. With bright sun illuminating everything, the lake seemed small; in the fog, we might have been on an endless sea.

Ever since I discovered how to read the glaciated landscape of Northern Minnesota and Wisconsin, I’ve been fascinated by these massive forces of nature. Admiring them from afar, seeing them up close, paddling among icebergs, touching their ice…glaciers are even more amazing than I’d expected…and I’m not done exploring them!

As we work on the new geology exhibit, I’m excited to help everyone understand how to see the footprint of past glaciers on our lakes, hills, trails, and Northwoods fun.

Note: Portions of this article were originally printed in 2018.

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

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Growing Up WILD exhibit will close on March 15, and The Northwoods ROCKS will open on May 2, 2023. Follow us on Facebook, Instagram, YouTube, and to see what we are up to.

Thursday, February 23, 2023

The Wandering Grosbeak

The vehicle pulled off to the side of the snow-packed gravel road was the first clue that we were about to see something exciting. I steered our car over as well, and my parents and I peered into the woods.

Movement and bright colors soon resolved into yellow birds with black and white wings hopping around a pile of black oil sunflower seeds. What luck! My parents had driven up from Iowa, and then we’d all traveled over a hundred miles from northern Wisconsin to the Sax-Zim Bog Important Bird Area in northern Minnesota in order to see unusual birds. Here they were!

Evening grosbeaks are colorful members of the finch family. They got their name not because they are the color of the setting sun, but because English settlers thought the birds only came out of the woods to sing at sundown. French settlers reportedly gave them the more accurate name of le gros-bec errant, the wandering grosbeak. These bright birds travel widely toward the best winter food sources in movements known as “irruptions.”

Here in Sax-Zim Bog, numerous bird feeders provide endless pounds of black oil sunflower seeds to entice grosbeaks into easily viewed locations. Out in the winter woods, evening grosbeaks are attracted to the large seeds of deciduous trees like maples, ashes, and boxelders.

As my parents and I checked out several different feeding stations in the bog, we were treated to the antics of flocks of 20-40 evening grosbeaks flitting between feeders and trees and making the sunny air ring with their bright, warbled calls.

While those birds were fun to watch, even more impressive flocks have been spotted at feeders in Washburn, Ashland, and Clam Lake, Wisconsin. Ryan Brady, conservation biologist with the Wisconsin DNR, has been posting photos and videos of more than 100 evening grosbeaks in his yard for most of the winter.

And yet, that abundance is deceiving. Between 1966 and 2019, evening grosbeak populations declined by an estimated 74 percent. The causes of this decline are not fully understood, but likely stem from changes in both their winter and summer food sources.

Spruce budworms – the destructive caterpillars of a little brown moth – are a favorite baby food for evening grosbeaks. Grosbeaks are so good at detecting spruce budworms that an influx of the birds is often humans’ first clue to the start of an outbreak. The birds stuff their chicks full of the juicy, protein-packed larvae, and experience excellent nest success.

After a couple years of high caterpillar numbers and high bird reproduction, budworm outbreaks wane naturally. Large numbers of birds are faced with food shortages. Cycles of natural budworm outbreaks, and shifts in how much humans try to control outbreaks through aerial spraying, impact how much baby food grosbeaks have access to from year to year, and decade to decade.

Back in the 1800s, evening grosbeaks were mostly a western species. In the early 1900s they started to move east, mostly in winter. It was around this time that boxelder was increasing in popularity as an ornamental tree, and would have provided a steady winter food supply.

In the 1950s, their winter food got another boost. During the post-World War II baby boom, boxelder trees became a favorite landscaping tree in new housing developments. While boxelder was native to much of New England, it became much more common and moved north into parts of Maine and nearby Canada where it hadn’t been before. In addition, the 1970s saw extensive spruce budworm outbreaks. The dramatic increase in both their summer and winter food at this time may have meant that evening grosbeak populations were unnaturally high at the start of the period of decline.

Logging, spraying for budworm, and diseases like West Nile likely ended the grosbeaks’ period of abundance. Now climate change threatens to disrupt our forests even more. As balsam firs and spruces shift north in the face of warming temperatures, the summer food sources for evening grosbeaks might decline enough that they can no longer breed south of Canada.

None of that was at the forefront of our minds as we watched the birds in Sax-Zim Bog. Evening grosbeaks were not the only attraction. Eager Canada jays swooped in to lick peanut butter off sticks. A boreal chickadee took their turn at the fatty feast, too. Red-breasted nuthatches snacked on seeds. Pine grosbeaks added their beautiful rosy hue to the bird rainbow. And a northern hawk owl perched stoically in an aspen tree.

For this winter at least, we can enjoy a colorful visit from le gros-bec errant.

Pine Grosbeak

Northern Hawk Owl

Red-breasted Nuthatch
Boreal Chickadee

Canada Jay

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

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum is now open with our exciting Growing Up WILD exhibit. Follow us on Facebook, Instagram, YouTube, and to see what we are up to.

Thursday, February 16, 2023

“The Last of Us” in Real Life

With a firmly packed trail under my feet, I could let my eyes wander. Blue sky peeked through gaps in the red pine canopy, and the orderly rows of their trunks made pleasing patterns against the snow. On this hike, though, I wasn’t looking for uniform trees. This was a scouting trip for an upcoming interpretive hike, and my eyes were peeled for special or unusual bits of nature that would make participants go “wow!”

Through a brushy patch I noted a young boxelder tree with winged samaras still drooping from the twigs. Across the trail, a cherry sapling sported the wrinkled growths of black knot fungus, and the leaves of a young oak tree fluttered in the wind. This could be a stop where I talk about easily visible clues to winter tree identification, I thought.

A few steps down the trail, another oak sapling caught my eye. This one was only chest high and barely half-an-inch in diameter where it disappeared into the snow. And it was hairy.

My second look revealed that the twigs were covered with small, shiny, brown domes, and from most of these domes sprouted a forest of little black clubs. Their shape reminded me of Earth tongue fungi and pin lichens, both of which I’ve written about previously. As I finished hiking the loop, I spotted these odd-looking twigs everywhere!

On a recent snowshoe hike, I found many twigs on oak saplings that were covered in scale insects who had been parasitized by fungi. Photo by Emily Stone.

The domes I recognized. Several years ago I spotted the same type of critter on an ironwood tree. These were scale insects. Like their relatives the aphids, scale larvae insert sucking mouthparts (called stylets) into the leaves and start drinking. In order to get enough nitrogen, they must drink an excessive amount of the sugar-rich sap, which they concentrate and excrete as “honeydew.” Ants take advantage of this just like they do with aphids, and can often be seen drinking honeydew off the scale insects.

As the nitrogen and sugar fuel their growth, the scale larvae molt. With each molt, their bodies become larger, and their legs become smaller. Finally, in late summer before their legs completely disappear, the nymphs walk back down the leaf stalk and onto their winter home on the twig. They build their waxy, protective shells, and do not move again. Spring brings maturity, egg laying, and death.

Death, in this case, came early. I sent a photo of the scale insects with clubs erupting from their shells to Britt Bunyard. Britt is the editor of Fungi Magazine and a frequent field trip leader for the Museum. I affectionately refer to him as “my mushroom guy” and send most fungi-related questions his way. He studied entomology as well, so this mystery was perfect for him.

Here’s an up-close view of what I believe to be the same pair of organisms. Photo by Michael Bohne, USDA Forest Service,

Britt wrote back that these fungi were most likely Cordyceps clavulata. Cordyceps fungi are well known to plant pathologists and agronomists because, according to Britt, “they are one of the rock stars of biocontrol of insect pests on economically important crops.” In other words, these fungi are on our side, and help control pests!

Cordyceps are fungi who parasitize insects (mostly). First, a spore encounters a tasty host, then it sends web-like mycelium throughout the body of the insect to digest it. Finally they send their club-like reproductive structure up into the air to release spores. The cycle repeats.

According to Britt, there is only one known reference to Cordyceps fungi parasitizing scale insects. This could be a unique observation and important to science! I have marching orders to collect samples for further research.

You may be familiar with Cordyceps, because HBO’s recent zombie thriller “The Last of Us” is purportedly about Cordyceps that switch from attacking insects to attacking humans. I’m not sure because I haven’t seen it. I don’t watch the horror/apocalypse genre, especially when it’s based in nature. (Read about the science behind the sci-fi here.) For one, I do NOT want to be thinking about that stuff while I’m in the woods. For two, real nature has plenty of suspense and gore if you know where to look! Luckily these real-life fungi are the good guys! They’ve just taken care of what looks like a huge outbreak of scale insects in this section of forest.

As I searched for more details, I discovered that oak lecanium scale insects become pests most often in cities. Sometimes it’s because the heat island effect in cities both stresses out the trees and allows the scale insects to develop faster. Sometimes it’s because spraying for mosquitoes has killed off the predators and parasites who would control the scale insects. I called around to nearby landowners, and no one admits to having sprayed for mosquitoes in this forest. My friend who hikes there in the summer confirms that there are plenty of skeeters on these trails. So, the cause of the outbreak remains a bit of a mystery.

Happily, mysteries are fun to teach about. Not only did I find something interesting to show the visitors next week, I discovered something that made even my mushroom guy go “wow!” Now that’s a successful hike.

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

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum is now open with our exciting Growing Up WILD exhibit. Follow us on Facebook, Instagram, YouTube, and to see what we are up to.

Thursday, February 9, 2023

Counting Cubs

With bright sunshine to provide at least the appearance of warmth, single digit temperatures didn’t phase us much. Hand and foot warmers took the edge off, too, as did the brisk pace set by college students from University of Wisconsin Stevens Point’s (UWSP) Wisconsin Black Bear Project.

The students weren’t following a designated trail, instead they were following the faint beeps of a radio collar worn by a female black bear in her den.

For over 30 years, students and professors from UWSP have conducted research on the seasonal movements, habitat selection, and reproduction of Wisconsin’s black bear population. During that period, bear numbers have risen from 9,000 to 24,000. The researchers’ hard work has contributed significantly to the body of knowledge about black bears in Wisconsin, and informs bear management, too.

On this late January morning, a small group of Wisconsin Master Naturalist volunteers were lucky enough to join a reconnaissance mission. The sow bear we headed toward had been caught in a barrel trap last fall and fitted with a collar. Although her age was unknown, she weighed more than 150 pounds at the time of capture, (she topped out the scale) which means she was big enough to have cubs. Students monitored her movements using radio telemetry equipment, and noted when and where she entered her den. Now, the question was, did she have cubs or yearlings?

Black bears have a unique reproductive cycle. Mating occurs in late May and June, and eggs are fertilized then. But after each one develops into a tiny ball of cells called a blastocyst, they hang out on pause for five months. If the sow puts on enough weight during her fall period of hyperphagia, then the blastocysts implant into the uterine wall in November and develop rapidly. If the sow has a lean fall, then her body won’t put her through the rigors of motherhood.

Cubs are born in January, weighing only a pound. According to the North American Bear Center in Ely, MN, “newborn cubs are smaller, relative to their mother’s size, than the young of any other placental mammal.” While it’s rumored that mama bears stay asleep while they give birth and discover a cute surprise in the spring, this is just folklore. Mother bears wake up to give birth and care for their young, although they do their best to conserve precious energy and fat stores.

At a respectful distance from the den, we paused to let the college students go ahead. Assistant Professor and Bear Project leader Cady Sartini answered our questions, and prepared us for what we’d see.

Cady Sartini talks about bear biology. Photo by Michael Mucha.

Like many mamas, this bear had excavated a den in sandy soil under roots and brush in a spruce bog. Some bears have been known to just lie down and let the snow cover them, but this expectant mother was a little more picky. Only females are radio collared and ear tagged, Cady told us, since the project is mostly interested in bear reproduction. Males range more widely, and don’t stay with their offspring. Cubs spend their second winter with their mother, too, and, ideally, female cubs who survive to be yearlings get a collar before their mom kicks them out.

A student returned to our group with exciting news—they could see the mama bear’s nose, and hear noises from at least two cubs! Most likely, the young cubs were hidden behind mama, away from the drafty entrance. From previous experience, researchers know that it’s important to observe a den for 20 minutes or so to make sure that they’ve given the cubs a chance to be heard. 

Confirming the presence of cubs or yearlings is essential because the research team plans to return in March. They will anesthetize the adult. The cubs will be counted, sexed, weighed, and aged by measuring the length of the hair between their ears. If there are yearlings in a den, the process becomes more complicated. They would be anesthetized along with the adult, and any female yearlings would be fitted with collars. Knowing what the researchers will encounter, and being able to plan for it, is key to making the process go smoothly. 

Caption: One of the student researchers from UW Stevens Point looks and listens for signs of cubs in an active bear den. Photo by Cheri Schultz.

Carefully and quietly, a few at a time, Master Naturalists were allowed to approach the den. Cady had explained that the bear would know we were there, but she would be trying her best to stay asleep. Disturbing hibernating bears is something that should be done as little as possible, and with valid research goals in mind. Just by nursing young, a female will lose around half a pound a day, and waking up wastes valuable energy.

Under the snow, the den hole seemed sandy, dark, and damp. The mother bear lay with her face buried and a paw over her ear, just as you would if you were trying to sleep in. From behind her came the pulsating grunts of warm, comfortable, nursing cubs. This sound tells mom that everything’s fine and she can stay right where she is. (You can listen to these sounds in the Museum’s current exhibit, Growing Up Wild.)

Later, one of the Master Naturalists reflected that “it is one thing to read that a sow bear gives birth to cubs while she hibernates and quite another to peer into the small opening of a bear’s den mid-winter, see her snout and a paw, and hear her mewling cubs from the darkness of the confines beyond. This was a gift I believe we all received with great gratitude.”

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

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