The Color Splash of Mountain-ash

In a landscape of winter white, bits of color really pop. Recently I was on the North Shore of Minnesota when they received several inches of fluffy, wonderful snow. Gray clouds hung low and continued to sprinkle fairy dust throughout the following day. Out on the cross-country ski trails above Grand Marais, my yellow jacket shone against the snow. When a strip of blue sky finally peeked through the clouds, that, too, glowed brightly. Full sun would have been blinding!

Spots of red also caught my eye. The forest seemed decked out for Christmas with clusters of mountain-ash berries adding color in the woods along the ski trails, around town, and on the rocky shore of Lake Superior. One section of scrubby forest between Highway 61 and the lake seemed to be almost entirely composed of berry-laden mountain-ash trees.

As the days grow ever shorter and darker this time of year, splashes of color like these berries do wonders for my mental health. Ruffed grouse appreciate them even more, I’m sure, as they perch in the dark purple twigs and nibble both berries and buds. The berries are acidic enough to last on the tree all winter, but if a flock of cedar waxwings descends, all the fruits may disappear in a single day. Thrushes, jays, catbirds, and grosbeaks, plus squirrels and small mammals, sometimes share in the feast.

Mountain-ash berries brighten up the winter woods, especially along the North Shore of Lake Superior. Photo by Kevin Friedman.

Grouse eating mountain-ash berries. Photo by Kevin Friedman.

The twigs of mountain-ash apparently are tasty, too, or at least nutritious. When I taught a wolf ecology course on the North Shore years ago, we observed the impacts of deer browse in different parts of wolf territories. Any mountain-ash short enough for deer to reach was deformed from their nibbling. On Isle Royale, scientists observed that over eighty percent of mountain-ash stems in study plots were browsed by moose. Moose have the advantage of height. Snowshoe hares must browse the lowest twigs with their sharp incisors, or wait for deep snow to give them a lift.

Photo by Emily Stone.

Back in the day, when I took a plant identification course at Northland College, we only learned two species—American mountain-ash (a native) and European mountain-ash (Sorbus aucuparia, introduced for landscaping). So, for years, when I’ve found these trees away from towns, I’ve called them all Sorbus americana. Recently, I’ve discovered that showy mountain-ash, Sorbus decora, is also native here, and is more common, at least in Wisconsin.

The three species are almost identical to the casual observer. While the leaves are slightly different sizes and shapes, this time of year the hairiness of the buds and berry stems seems to be the best distinguishing characteristic. The buds of the European species will be covered with long, white hairs. Showy mountain-ash twigs and buds are pubescent (with short hairs) and American mountain-ash twigs and buds are usually smooth and hairless.

I always thought this tree was a European Mountain-ash. Now I'm not so sure--but it's been cut down so I can't go back and look closer! Photo by Emily Stone.

All of these species are good wildlife and landscaping trees, although planting the native mountain-ashes is preferred, since the European ones have been known to escape into the wild. While their showy, rounded clusters of white flowers don’t look like roses from afar, they are all part of the Rose Family. A closer look at the flowers reveals five white petals very similar to the blossoms on their cousins: strawberries, raspberries, cherries, and apples. Even the fruits of mountain-ash look like mini apples.

I took this photo of mountain-ash flowers on Hunger Mountain in Vermont during graduate school. From the leave length-to-width ration I measured off the photo, this is Sorbus decorum. Photo by Emily Stone.

Mountain-ash drupes that look like mini apples. Photo by Kevin Friedman. 

The hyphen in their name indicates that they aren’t really related to ash trees. Mountain-ash are called that because they have compound leaves with long, narrow leaflets, similar to true ash trees. Unlike true ash trees, these wonderful wildlife trees won’t be impacted by the deadly emerald ash borer insects.

Ash-like leaves on a mountain-ash. Photo by Emily Stone.

Both of our native species reach their southwestern edge in northern Wisconsin and Minnesota, and extend north and east from there. American mountain-ash also extends down the spine of the Appalachians. The happiest specimens seem to be concentrated along the north shores of Lake Superior and Lake Huron. They are quite common among the balsam fir trees on Isle Royale as well. On the water-limited bedrock along Artist’s Point in Grand Marais, I’ve noticed they can remain quite shrubby, and a heat wave last summer left their leaves brown and crispy.

The color these wonderful berries bring to our winter woods is only one reason I enjoy them. Getting to watch and listen to the flocks of birds they attract is another. And now, the challenge of learning to distinguish the two native species will give me an excuse to look more closely at their leaves and twigs. In doing that, I bet I’ll learn something else new, too.

Cedar waxwing in a tree that I once thought was European mountain-ash, and now can't be sure. Photo by Emily Stone. 

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

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

Red-eyed Vireo Nests: Hidden Treasures of See-Through Season

Cold air filled my lungs as I climbed yet another flight of stairs up to the observation tower at Copper Falls State Park. It was interesting looking out through the twigs and trunks. The lack of leaves in this “see-through season” reveals aspects of the landscape otherwise obscured. For example, “Check out that nest!” I exclaimed to my friend, and we admired the small cup suspended between a Y in the sugar maple twigs. It was a lovely reminder of a favorite summer resident, now gone for the winter.

Can you see through the forest and spot the vireo nest? It's fun to get to look down on one! Photo by Emily Stone.

The placement of the nest dangling below the forked twigs, plus the few pale strips of paper from a bald-faced hornet nest woven among grass, bark, and pine needles, told me that it was likely built by a red-eyed vireo. While red-eyed vireos are one of the most common birds of eastern and central North America, these small, olive-green songbirds are hard to see among the leaves in the dense forests they prefer. Once the leaves fall, though, their nests are suddenly one of the most visible and recognizable of any songbird.

It's the female vireo who builds the nest in spring. She usually chooses a deciduous tree or shrub and places the nest 10-15 feet above the ground, and far enough out from the trunk so that it doesn’t block their view. Suspending a nest near the tips of thin branches reduces access for heavy nest predators like squirrels. On the chosen branch, the vireo weaves together fibrous strips of the inner bark of trees and other plant fibers to suspend the nest between the twigs. Pine needles often line the 2-inch-diameter inner cup. Spider webs help stick it all together.

As mentioned above, vireos often decorate the outside of their masterpiece with paper strips stolen from last season’s abandoned bald-faced hornet nests, even when those nests are not found nearby. Naturalists suspect that décor can trick potential predators into thinking it’s the nest of a furious stinger instead of a tasty songbird. Strips of birch bark often add to the papery look.

Almost every bird nest is a work of art. They are also feats of engineering that gently cup fragile eggs and chicks while withstanding storms, and then remain intact long past their intended use. Plus, they were constructed without opposable thumbs!

There’s a display at the Cable Natural History Museum that reinforces my awe. A Museum naturalist, decades ago, deconstructed a red-eyed vireo nest and catalogued each component. The nest included: 1 cherry stem, 1 piece of paper, 1 ball of tree sap, 2 pieces of thread, 7 fir needles, 9 plant buds, 69 pine needle sheaths, 16 pieces of hornet nest, 24 twigs, 50 animal hairs, 346 pieces of birch bark, 347 pine needles, 427 pieces of inner bark, and 16 pieces of spider web. The naturalist arranged these objects, minus the spider webs, in a beautiful display that hangs in our classroom.

This deconstructed vireo nest is a favorite display at the Cable Natural History Museum. The number of different nest materials is astounding! Photo by Emily Stone.

Despite the birds’ hard work, and the hornet paper, red-eyed vireo nests are vulnerable to nest parasitism by brown-headed cowbirds. When vireos can place their nests in the heart of a forest this is less common, but any vireo nest near a forest edge may end up with a cowbird egg among the 3-4 vireo eggs. The cowbird hatches first, grows faster and bigger, and will often push their adopted siblings out of the nest. Occasionally vireos will cover up the cowbird eggs and try again, but more often the parents just feed the big baby as one of their own. Vireos may nest multiple times per summer, especially if early nests fail.

Recently I noticed two vireo nests in the tops of trees surrounding my own driveway. Although the nests are much higher than average for a red-eyed vireo, that was the only vireo species I heard singing last summer. Warbling vireos are known to nest up high, but I would have recognized their run-on song, which sounds like them saying, as if to a caterpillar, “when I see you, I will squeeze you, and I’ll squeeze you ‘til you squirt!” Instead, I heard red-eyed vireos singing the incessant phrases “hear I am, over here, in a tree, look at me, vireo!”

All summer, it’s much easier to hear red-eyed vireos singing than to actually see one high in the treetops. This signing male was a lucky find! Photo by Emily Stone.

As their abandoned nests fill with white snow instead of white eggs, the vireos themselves are filling up on fruit in the Amazon basin of South America. When they return next spring, the females will start building new nests. Once the leaves fall, we’ll have a whole new set of treasures to discover in “see-through season.”

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

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

Winter Songs of White-Throated Sparrows

During a recent week-long visit to the Washington D.C. area, finding pockets of nature with plenty of birds was a boon to our sanity. Early in the week, my partner and I drove west to the little town of Linden, Virginia, which provided the nearest access to the Appalachian Trail. Even as we crossed the gravel parking lot toward the oak-filled forest and uphill climb, a wistful-sounding white-throated sparrow sang from the brush. We looked at each other and grinned.

The rhythmic whistle of white-throated sparrows is part of the spring and summer soundtrack of the Northwoods. No hike or paddle is complete without their song. Two decades ago, while my parents helped me pack for a May trip to the Boundary Waters, this was the one song they’d insisted I learn to recognize. Luckily, it wasn’t hard. The white-throat’s pattern of two long starter notes followed by three sets of triplets is often described with the mnemonic “Oh, sweet Canada, Canada, Canada” and is quite distinctive.

But it’s been a month or more since we heard the last sparrow sing goodbye to the Northwoods as they headed south. I felt a little sheepish, realizing I’d never paid much attention to where they were going. Virginia, as it turns out, is in the core of their winter range. As we hiked, it seemed like almost every scritching sound in the underbrush turned out to be a foraging sparrow using their two-footed hops to unearth seeds in the duff. Getting a glimpse of snazzy black-and-white head stripes, yellow near the eyes, and the signature white throat patch confirmed their identity.

White-throated Sparrow. Photo by Larry Stone. 

Higher up in the trees, cardinals whistled, tufted titmice peter-peter-petered, Carolina wrens chattered energetically, and Carolina chickadees scolded each other. These are common winter compatriots of the white-throated sparrows.

A few days later, we crossed over a babbling brook on a wide wooden bridge and into the “R. Randolph Buckley ‘8-Acre’ Park” in Clifton, Virginia. Large beech trees, sycamores, oaks, maples, and pines, plus musclewood and a blooming witch hazel, welcomed us into this little neighborhood woodland. As we followed our ears to a white-breasted nuthatch high in a pine tree, a song burst out of a bush beside us. The white-throated sparrow riffed on the usual song, experimenting with a gravely “sweet can-a-NA-da can-a!” “Jazzy!” We laughed to each other. Listen here!

I don’t usually expect birds to sing in their winter habitat. Birds’ songs are typically used to attract mates and defend territories, and therefore are most useful in spring and summer. Many birds get by using simple call notes to communicate within a flock over the winter. So, we figured we were hearing young males practicing for the coming year. That would also explain why the amateurs’ “sub-songs” were tending shorter and with more variations in rhythm and tone. As it turns out, that was only part of the story.

Singing on their wintering grounds is more than just training for the youngsters. It’s an important avenue for learning new songs! In 1999, two ornithologists in western Canada heard white-throated sparrows singing a shorter song. Instead of the triplet “can-a-da,” they heard a doublet, “can-a.” Over the next few years, scientists studied older recordings of the white-throat’s songs, and made new observations, too. In ten years, by 2019, the new song had been adopted as far east as Ontario. Currently, you can only hear the original song in the farthest east populations.

How did the new song spread so quickly when these sparrows breed clear across Canada? They learned from each other on their wintering grounds and then took the new “slang” back home in spring. This goes against traditional wisdom, that young birds learn to sing from their fathers before they leave home. Song spread is facilitated because male sparrows from all over are extra concentrated. They tend to stick to the north end of their winter range—poised for a rapid return to claim a breeding territory in spring—while females go farther south to avoid competition with the males.

Just singing a new song isn’t enough to make birds successful, though. If it’s not recognizable to your own species, or sounds weird, a new song might hurt your breeding success. In this case, females prefer the novelty of the males’ new song, and this reinforces the change.

I’d heard about the white-throated sparrow’s changing songs before, but it wasn’t until I investigated the young birds’ jazzy riff that I realized it had taken over so completely. I’ve been trying to shoehorn their summer songs into the familiar “Oh, sweet Canada” mnemonic, and attributing variation to lazy birds. Now I know that something much more interesting is going on. Just like the sparrows, I learned something new in their winter habitat.

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

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

A Dandelion Smile

Author’s Note: This article was first published in 2013 and has been updated for 2024.

A chilly breeze whipped around my head. Even a pale sun peeking through racing clouds did not seem to improve the temperature. Head down, I hurried toward the post office. Then, a spot of color made me stop and smile. A single yellow dandelion and their star of vibrant, toothy leaves nestled into the grass.

Photo from November 16, 2024, when there are even MORE dandelions in bloom than 2013!

I’ve always loved dandelions. They popped up every summer in the kingdom of make-believe that was my yard, and created a sea of sunshine in the farmer’s hayfield across the back fence. Every spring I still pick one of the hardy flowers to give to my mom for her late April birthday. Unless I’ve flattened them in a card to send through the mail, she still sticks the dandelion in a little vase on the sill above the kitchen sink.

As a kid, I continued picking dandelions all summer long. I’d split the stems lengthwise and watch as they coiled into beautiful curlicues when dunked in cold water. I soaked the fuzzy blossoms in water and made “lemonade” that I never drank. I almost hyperventilated while trying to blow every parachuted seed off the stem to make a wish. And every T-shirt I owned was stained with little brown circles from the juicy stems.

Even today, despite my awareness that dandelions are invasive weeds, I can’t help admiring their tenacity. And I’m not alone. Buddhist monk, Thich Nhat Hanh, shared this poem (written by a student) in his book, Peace is Every Step.

I have lost my smile,

but don’t worry.

The dandelion has it.

So I smile whenever I see those cheerful weeds. Sometimes I even brave their bitterness and eat young leaves in salad. Other folks swear by the sap as a remedy for warts or foot fungus. Turns out, the dandelion may be more useful than I ever imagined!

The Kazakh dandelion (Taraxacum kok-saghyz, a relative of the one in your yard), is an excellent source of natural rubber. The milky sap in the root is so high in latex that one field of dandelions produces as much latex as the same size plot of rubber trees. In addition, the quality of dandelion latex is the same as latex from a rubber tree, and can be substituted one-for-one in the rubber formulation. To top it all off, dandelion latex does not seem to trigger allergic reactions!

Russians discovered this amazing dandelion in the early 1930s, in Kazakhstan. They tried to develop it as a domestic source of rubber. During World War II, when the Japanese controlled the supplies of rubber from Southeast Asia, researchers in the United States, Germany, Sweden, and Spain all jumped on the dandelion-rubber bandwagon. In the U.S. alone, land grant universities in 40 states conducted research on this lowly plant.

Most research came to a halt after the war ended in 1945. When this article was first published in 2013, an internet search for dandelion rubber revealed that at least three separate tire companies were partnering with research institutions to make this new source of rubber viable on a commercial scale. Germany's Fraunhofer Institute for Molecular Biology and Applied Ecology is still working with Continental Tires. Bridgestone was working with the Program for Excellence in Natural Rubber Alternatives at Ohio State University. Multinational tire manufacturer, Apollo Vredestein, collaborated on a dandelion rubber project with KeyGene.

Despite the many benefits of dandelions—they grow like weeds on many soil types, reproduce like weeds with lots of seed, and thrive in northern climates instead of sub-tropical forests—there are some obstacles, too. Dandelion juice transforms from a liquid to a solid on contact with the air—a process known as polymerization. This means that processors must use turpentine to chemically extract the latex from dandelion roots.

To eliminate the enzyme responsible for polymerization, German scientists at the Fraunhofer Institute engineered a special virus. According to a Discovery News article, “Once inside, the virus deleted the offending genetic sequence from the Russian dandelion's DNA. Pop the head off an infected dandelion, and the latex begins to flow freely.” (Watch out, Mom! My shirts will have more than just little brown circular stains!)

It worked. In Europe, creating transgenic dandelions has been controversial. Now German researchers are using traditional selective breeding techniques to accomplish the same thing. Hydroponic growing systems where roots can be harvested over and over are also showing promise. At the same time, Continental Tire is working with researchers to build the first ever commercial-scale processing plant. This becomes more and more important as natural rubber production from trees faces disease, climate change, and increasing labor costs. Synthetic rubber made from fossil fuels has different properties and is often mixed with natural rubber.

Maybe in the future, that field of dandelions across the back fence won’t be full of weeds. It will be full of a cash crop, harvested by the same machines used to pull tulip bulbs. The sticky sap, once a stain on my shirt, will instead help my airplane land safely in Germany so I can go for a ride on a bike or in a car with dandelion tires. That might even make me smile.

“What is a weed? A plant whose virtues have never been discovered.”

—Ralph Waldo Emerson

Photo from November 16, 2024, when there are even MORE dandelions in bloom than 2013!

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

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

Adventures with Bagworm Moths

The relatively mild weather we’ve been having this fall has been wonderful for hiking. Unfortunately, it’s also good weather for outdoor chores, so I don’t have freezing cold and snow as excuses to let the windows go unwashed. As I brushed off spider webs, I noticed small brown somethings stubbornly stuck to the windows and frames. The objects were each a tiny cluster of dead plant stems formed into a cylinder and glued to the surface with a circle of white at one end.

This jogged a memory, and I thought back to our moth workshop last summer. Kyle Johnson, Minnesota Biological Survey (MBS) Entomologist, found an impressive number of caterpillars and moths for us to learn about in just 24 hours. During that workshop, at the end of July, we spotted one of these little brown cases on the surface of a leatherwood leaf. Kyle explained that they were movable camouflage for the larvae of bagworm moths. I stored that information away for future use.

We spotted this bagworm moth larvae on a leatherwood leaf during the moth workshop in July. Photo by Emily Stone.

The future is here! I snapped some photos of the bagworm cases before scraping them off the windows with my fingernail, and scrubbed the glass clean. As I started investigating the bagworms further, my searches turned up some dire-sounding warnings about how they can defoliate evergreen trees in your yard. The photos of the cases didn’t look quite right, though. Eventually, I discovered that there are two species of case-forming insects sometimes called common bagworms. One has the tongue-twister name of Thyridopteryx ephemeraeformis and is also known as the evergreen bagworm. Although they can be destructive to juniper and white cedar, they are native to North America. The other insect is Psyche casta, also known as the grass bagworm. This matched the cases I found much better! Both types of bagworms are the larvae of tiny moths.

While they don’t seem to cause problems, grass bagworms were introduced from Europe around 1931 and have spread from Boston across southeastern Canada, and as far west as Minnesota. Modern information about them is pretty sparse, but in 1934, when they were new and interesting, Donald W. Farquhar of Harvard University wrote a comprehensive observation of their unusual life cycle.

Farquhar observed the larvae hatching in June and July. Their first act is to spin a silken sleeping bag and then decorate it with bits of their surroundings. Grass bagworms use little straws of dry grass, which also creates excellent camouflage. This stage reminds me of caddisflies, which are unrelated aquatic larvae who also use silk and local materials to build a protective case. In both groups of insects, the cases are distinctive enough to help with identification. I had split open one of the cases after scraping it off my window, and I did find white silk lining the case of grass.

Once protected, the bagworm sticks their head and thorax out of the case to crawl around and feed. Although the evergreen bagworm seems to cause whole trees to turn brown, I think that grass bagworms just skeletonize patches on broader leaves. Farquhar reports that they eat grasses, mosses, lichens, and “other low plants.” He also observed them eating the scale insects who cause beech bark disease out East, and even cannibalizing their peers in a laboratory setting. As with quite a few moth species, they must get all of their eating done in childhood, because the adults have no mouths!

This larval childhood is also when they do their traveling. Sometimes, just after spinning their tiny silk bag, a larva will drop down on a thread and catch a ride on the wind, similar to a spiderling ballooning on their silk. Humans transport them even farther as we move the objects they call home. Even with tiny legs, walking places is an option, too. Full-grown larvae will climb up trees, buildings, fence posts, stone walls, and my first-floor windows to get ready to pupate and go through metamorphosis. Monarch butterfly caterpillars also go through this wandering phase.

According to Farquhar, all of that takes 11 months. The larvae spend the winter under rocks or in the crevices of tree bark. Fresh spring food allows them to grow faster, and by May they are ready to pupate and become adults.

This bagworm moth case still has the exoskeleton of the pupae sticking out one end! Photo by Emily Stone.

Female bagworm moths have no wings. They emerge from their case, hold onto the bag, and in Farquhar’s words, she “liberates the attractant which summons males within perceiving distance.” In other words, she releases pheromones. Males, who do have strong wings, follow her scent upwind and then search on foot to find her. The two mate, and then the female reinserts her ovipositor into her empty case and squirts in about 150 eggs. She closes up the end of the case with white fuzz, then drops to the ground to die. The eggs hatch after a couple of weeks, and the cycle begins again.

Although I’ve noticed bagworm cases before, I didn’t know anything about their life cycle, or why I find their old cases on walls and windows instead of plants. Now I do! So I’m grateful that this warm fall weather allows me to check things off my to-do list.

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

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

Cyanobacteria Then and Now

I don’t quite know what to do with myself in this warm fall weather. Shouldn’t we be crunching through snow or at least hiking on frozen ground? Shouldn’t my watercraft all be in storage and my skis be by the front door? Instead, on an afternoon in late October, I found myself on the shore of Lake Namakagon, paddleboard resting at my feet.

Stand-up paddleboarding is a new skill I picked up this summer. I found it useful for navigating swells on Lake Superior, and spent a day exploring the sea caves. Far more often, though, I’d get done with a bike ride, paddle out beyond the weeds and muck at my shoreline, and using the paddleboard as a swim raft, jump in! Even though it was much warmer than the big lake, a dip in Lake Namakagon was refreshing.

But on that October day, the gentle waves that lapped at my toes were bright green. In almost any other circumstance I’d find that color beautiful, but the thick soup of algae made my stomach drop. There would be no refreshing swim.

Blue-green algae blooms are an increasing issue even in wild lakes. I spotted this algae bloom on Crooked Lake in the Boundary Waters Canoe Area Wilderness in late September. Photo by Emily Stone.

I stared at my feet for a minute, deciding whether or not I should even attempt to paddle through the goo. Then a spot of deep red caught my eye. Among the dark gray rocks along the shore was one lovely pebble made of jasper. That lifted my mood just enough to propel me away from shore.

As my paddle created swirling patterns in the green scum, I struggled with finding beauty in such a mess. This, I guessed, was a bloom of blue-green algae. Warm weather, calm winds, and plenty of nitrogen and phosphorus from lawns, farms, and autumn leaves increasingly lead to algae blooms in late summer and early fall.

Days of calm, warm water with plenty of nutrients often lead to blooms of blue-green algae in late summer and fall. These cloud reflections on Lake Namakagon hide a thick, green soup. Photo by Emily Stone.

Algae are the base of the aquatic food chain. They use energy from the Sun to transform carbon dioxide and water into sugar. Tiny zooplankton eat the algae, and bigger critters eat the zooplankton, eventually feeding fish, eagles, and us. Blue-green algae aren’t true algae, though. They are a type of bacteria who invented photosynthesis.

On land, cyanobacteria are part of cryptobiotic crusts, which hold sandy soils in place. As a partner in some species of lichens, they fix nitrogen out of thin air. In the water, though, cyanobacteria are becoming more common, and more problematic. The thick film they form on the surface reduces sunlight to plants below. They can clog water filters. And they sometimes, but not always, produce toxins that are harmful to pets, livestock, and humans.

My thoughts strayed back to the red pebble near the shore. Jasper is a form of mineral-stained quartz that once formed as layers within iron ore. I enjoy finding them because they are part of such a unique story. A story, I realized with a jolt, where cyanobacteria play a leading role.

Once upon a time, and by that, I mean 1.9 billion years ago, the atmosphere was filled with carbon dioxide and methane, and the first inklings of life had only just begun. Volcanic activity in the early oceans, and erosion off the few continents, enriched the water with iron and silica.

Cyanobacteria bloomed in those mineral-rich seas, and they also produced at least one type of toxin: oxygen. Free oxygen wasn’t part of the Earth’s early atmosphere, and it was lethal to the first forms of life. At first, the oxygen reacted with the dissolved iron and silica, removing itself from the water by precipitating jasper and other minerals. When cyanobacteria doing photosynthesis pumped out more oxygen than the minerals could remove from the water, though, they poisoned themselves. Boom and bust cycles of cyanobacteria, plus other seasonal and erosional events, resulted in bands of iron-rich rock with different colors, textures, and thickness. Conditions on Earth have changed so much over millennia that this type of rock may never form again.

Like me learning the new skill of paddleboarding, cyanobacteria eventually evolved enzymes that allowed them to live with oxygen. No longer at risk of poisoning themselves with the element, they proliferated wildly, their oxygen waste sweeping most of the iron and silica out of the ocean water for good. Then excess oxygen, no longer tied up with iron, escaped into the air, and began creating the atmosphere we enjoy today.

It's a little ironic, then, that one of the issues with cyanobacteria on the modern Earth is that when they die, sink to the bottom of a lake, and decompose, they deplete the oxygen that life now requires.

A few days after that soupy paddle, the Halloween snowstorm stirred up the lake, and the red jasper at my landing disappeared. The storm waves also dispersed the cyanobacteria, at least until next summer. Over the course of Earth’s history, these little beings have played many roles. Were they heroes for giving us oxygen? Are they villains for gumming up our lakes? Maybe they are simply one part of a long and complicated story.

From the Wisconsin DNR:

"It’s very helpful for us to receive bloom reports from the public. You can email them to DNRHABS@wisconsin.gov, and please include photos for verification when possible. If you are ever at the Lake Superior shore and see a bloom, please let us know ASAP by email or by  texting Gina LaLiberte, Statewide Harmful Algal Bloom Coordinator and Inland Beach Monitoring Coordinator, at 608-640-7910. We have a rapid response group set up to grab samples from the (usually) very short-lived Superior blooms."

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

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

In the Dark

The recent Wisconsin Association of Environmental Education annual conference was held at Upham Woods Outdoor Learning Center on the banks of the Wisconsin River. It was a beautiful setting…even after dark! Photo by Emily Stone.

Light from the dining hall at Upham Woods Outdoor Learning Center spilled out, down the hill, under the pines, and onto the bank of the Wisconsin River, where a handful of environmental educators were waiting for a night hike to begin.

I almost hadn’t joined the group. This was the final night of the Wisconsin Association of Environmental Education annual conference, and I had a long drive home the next day. Being sleepy for that wouldn’t be ideal. But it had been years since I’d been on a night hike, and I didn’t want to miss out.

“Have you ever been on a night hike?” asked one of the activity leaders, who were all graduate students at UW-Stevens Point. “Hasn’t everybody?” asked one young woman, who, by way of explanation, told harrowing tales of following her big brother into the dark for numerous childhood adventures. In this organized context, a few of us explained, night hike means something a little more educational…and safe.

I’d become adept at leading night hikes when I worked at a science camp in the redwoods of Sonoma County, California. The combination of few mosquitoes and temperatures that rarely dropped below freezing made being outside at night there far more pleasant than most of my midwestern experiences. Each week, I’d have a new trail group of 15 to 20 fifth or sixth graders, often from a big city. Each week, I’d take the kids on a night hike where we’d spend an hour or so experiencing the night and doing little experiments to highlight animal adaptations to darkness. I loved it. I’d never stopped to consider how the students felt, though.

After a quick introduction in the light of the dining hall, the hike facilitators led us down a trail. The tread was wide and flat, and I relished the chance to practice my old technique of “seeing with my feet” by placing my steps carefully and sensing where the packed trail became soft edge. At a wide spot, we paused and gathered in a circle.

The instructors introduced the idea of predators using their sense of smell to find prey in the dark. Then they passed out little paper envelopes filled with something scented. There were three packets of each different scent, they told us. Our job was to find all of the people with the same scent. No flashlights allowed!

I sniffed my own envelope, and discovered what was definitely a flavor of tea leaves. Maybe vanilla chai? This immediately brought back memories of raiding the tea selection in my camp’s dining hall to freshen up my set of paired scents. Back then, I had explained the activity as male moths finding females by following their airborne pheromones, but it was basically the same.

As I milled around the Upham Woods group sniffing everyone’s packets to find a match, my nose quickly became overwhelmed. This was harder than I expected! I wondered if the tea scents I’d chosen back in the day had been as distinct to the kids as they’d been to me when I was choosing them in the well-lit dining hall?

Flashlights snapped on again as we started moving farther down the trail. My first reaction was to be frustrated. I’d always loved the challenge—and then the awareness gained—from walking without a light. But as the trail grew rougher, and the drop-off grew steeper, I softened my opinion of the lights, and made sure to fall into step near someone who’d remembered to bring a flashlight. Walking in the dark had been a lot easier on familiar trails.

We hiked for a while, making a few more stops before finding ourselves back in the yard of the learning center dorms. We were instructed to partner up, and choose which one of us was predator, and which was prey. Meanwhile, a grad student set up a playing field with orange cones at the four corners and stuffed animals scattered around. The activity facilitator was holding blindfolds.

This wasn’t an activity I recognized, and for a second, a touch of anxiety bubbled up. I was glad to have a friend nearby who I could trust as a partner, but still I worried. What would we have to do while blindfolded? Would I succeed? Would I be safe? And then I wondered—is that how my students felt back in the redwoods? Did I make them nervous with my odd activities that I thought were so fun? In the end, my friend and I came up with a code of chickadee calls for the sighted partner to direct the blindfolded one to pick up the stuffed animals. We didn’t win the game, but our system worked, and we had fun.

As all the night hikers formed a circle to wrap up the experience, the leaders asked us what we’d learned. The science wasn’t new to me, and most of the activities weren’t unfamiliar either, but I still learned something big: empathy. The experience of being in control of a night hike in familiar territory was far different than being a participant in a new place. Next time I lead a night hike, I’ll make sure that my students aren’t quite so in the dark.

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

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