Thursday, August 27, 2020

Rare Plants in a Rare Place

An old two-track led us into the woods, but almost immediately we veered left and crashed off into the unknown. Bushwhacking means alternating between watching your feet on the uneven ground, and protecting your eyes as twigs swing back or appear out of nowhere, so when I finally looked up, I was stunned. A bedrock cliff rose straight out of the creek bed we’d just crossed. Where were we? 

The craggy rocks, deep hemlock shade, and lush understory of ferns felt more like my botany field trips in the mountains of Maine, New Hampshire, and Vermont, than plain old Wisconsin. As I admired exposed faces of pink granite, it dawned on me that these rocks are part of a mountain range—albeit a very old and worn-down one. The low hills of Penokee Range stick up higher than most other things in Northern Wisconsin, (but lower than the younger mountains out east,) and also contain some of the highest quality plant communities in our area.

“Here it is,” came Steve Spickerman’s voice from up ahead. Spickerman is the Forest Ecologist for the Great Divide District of the Chequamegon-Nicolet National Forest (CNNF), and part of his job is keeping track of how rare plants are doing. I picked my way over moss-covered rocks toward Steve, and found a familiar-looking fern nestled in among boulders near his feet. It wasn’t familiar because I’ve seen it recently, but because I used to see it all the time in Maine and Vermont while I was in graduate school at the University of Vermont.

Braun’s Holly Fern has evergreen leaves and likes dark, damp habitats. 
Photo by Emily Stone.

While common out east, Braun's holly fern (Polystichum braunii), is a Wisconsin Threatened plant. Its evergreen leaves were shiny and robust, and near the ground the stalks were fringed with big, papery scales in an orangey shade of tan. This fern needs the cool, shady habitat often found on rocky, forested slopes; in ravine bottoms; and at the bases of cliffs. Check, check, and check. Wisconsin’s climate is likely a little on the dry side for holly fern, which may be why it is uncommon here. 

Around the world, this same species is native to Alaska, British Colombia, Newfoundland, Europe, China, and Japan. Braun’s holly fern also occurs within sight of the popular hiking trail at the nearby St. Peter’s Dome recreation area, but hardly anyone pauses long enough to notice. I, for one, am typically focused on spring wildflowers instead of the green backdrop of ferns. 

As we meandered farther down the ravine, the angular rocks went from being the size of basketballs and wagons, to being the size of refrigerators and sofas, sometimes with slopes of smaller talus intermixed. On one of those jumbled slopes, Steve stopped again. This time, the fern at his feet wasn’t robust and evergreen, it was flimsy looking and yellow around the edges. Its fronds were also a little shorter and wider than the typical fern geometry. The leaves will soon wilt into the ground for the winter, and begin from scratch next spring. 

Spreading wood fern (Dryopteris expansa) is another cosmopolitan species. It was first described in Germany, and also grows in Spain, Greece, eastern Asia, and California. According to the Wisconsin DNR, the habitat of this “Special Concern” plant is, “cool coniferous (balsam-fir, white cedar, hemlock) to mixed forests, sometimes in cold canyons.”

Spreading wood fern is a species of “Special Concern” in Wisconsin. Photo by Emily Stone.

Finding these two ferns—with their surrounding rock fields showing few signs of disturbance—was pretty much all that was needed for the official rare plant survey that was our goal for the day. With some species, like the highly rare and coveted ginseng, the botanists will actually count and mark individual plants so they know for sure when one is gone (vs. just being hard to find). These ferns only require a general check-up every few years. 

“I have the best job on the Forest,” Steve told me as we admired the unique landscape. His field tech, Stephen White, who just earned a permanent position, nodded along in agreement. These guys are a testament to the fact that the Forest Service isn’t just about cutting trees. They also manage landscapes for plants who could never become lumber, and for wildlife who no one hunts. In order to manage well, they do lots of scientific research and monitoring, too. 

Steve Spickerman, Forest Ecologist for the Great Divide District of the Chequamegon-Nicolet National Forest, points out more rare ferns on rocky cliff. Photo by Emily Stone.

Even with rare ferns all around my feet, I couldn’t stop looking up. Sheer cliffs, talus slopes, twisted trees growing out of giant boulder fields…it really didn’t feel like Wisconsin. With such a locally rare habitat type, it’s no surprise that this area—the untracked forest beyond tourist-packed Morgan Falls—has one of the highest concentrations of rare plants on the entire Chequamegon-Nicolet National Forest. 

The specialness of this area has been on many peoples’ radar for decades. The area around St. Peter’s Dome was recommended for inclusion in the Eastern Wilderness Areas Act of 1975, but a snowmobile trail through the center of it was just too popular. Instead, it’s been designated as a Special Management Area, a Research Natural Area, a State Natural Area, and an Important Bird Area.

As I scribbled notes about the day in my little field notebook, Steve chimed in. “Please make sure people know that this area is out here for them to enjoy…but there are rare plants, rare snails, and fragile habitats everywhere, so they should be careful to stay on the trail.” That’s good advice for many reasons, including the chance that you might get lost in a place that looks nothing like Wisconsin.

Emily’s award-winning second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at Or order it from our friends at to receive free shipping!

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 brand-new Mysteries of the Night exhibit. Connect with us on Facebook, Instagram, YouTube, and to see what we are up to.

Thursday, August 20, 2020

Ospreys Right on Schedule

The setting sun was in my eyes and a headwind in my face as I rounded one of the many curves on County Highway D along the eastern shore of Lake Namakagon. Eager to see today’s news, I squinted through the trees as I coasted along, and watched for that first glimpse of the nest. Who would be home today?

Visible by boat, car, and beer-and-pizza deck, the osprey nest near the Loon Saloon on Lake Namakagon is a staple of local wildlife watching. This year, my usual schedule disrupted, I’ve made the nest a destination on more bike rides than ever before, and was rewarded with many great osprey observations. 

As soon as cold winds first licked at patches of open water last spring, I was out searching for returning migrants. In my Runkeeper app, I labeled my bike rides with who I observed. April 1: no osprey. April 10: loons, but no osprey. April 15: one osprey on the nest. April 16: Two ospreys on the nest!

Male and female ospreys return back to the same nesting territory year after year. Within a pair, you can usually tell identify the female by the darker brown streaking on her chest. Photo by Emily Stone.

What a shock it must be for these world travelers to leave their wintering ground in Florida or South America and arrive “home” to the Northwoods with ice in the bays, snow squalls blustering, and ice storms threatening. As with many birds, the male arrives on the territory first, and the female joins him soon after. Ospreys are pretty devoted to their mate and their territory. It saves them a lot of trouble to simply head for home and know that your compatible partner will show up there, too. 

Through the end of June, my observations were pretty ambiguous. What did it mean to see one, two or no osprey on the nest? Were the missing ospreys off hunting? Was one hunkered down below the sides of the artificial nesting platform perched on top of a tall pole? 

Once I caught sight of an osprey carrying a stick. This was probably the male, since he brings sticks as a part of his courtship ritual, and the female will arrange them to her liking. Nest building sometimes continues through incubation and early chick-hood, so I couldn’t be sure what it meant about their schedule. After the pair copulates, it takes 14 days for the female to lay her first egg. She’ll lay another egg every one to three days, ending up with between 1 to 4. That’s weeks of action that I couldn’t see from the ground. 

Males occasionally take a turn at incubating during the day, but females cover the nest all of the 37 nights it will take them to hatch. She starts incubating as soon as the first egg is laid, and the chicks hatch in the order they were laid. Those third or fourth chicks are often much smaller, and are the most likely not to survive. 

Finally, on June 23, I hit the jackpot. One adult osprey perched on the edge of the nest, and two small heads poked up above the wooden rim. In the dim evening light I couldn’t see many details, but two days later I again saw a juvenile’s head in better light. Already past the downy stage, the little one was sporting small, sleek feathers with the distinctive black eye stripe of their parents already visible. Both ospreys’ eyes glowed in the sunlight—the chick’s were dark red (a juvenile trait) and the adult’s were yellow. I later heard reports that there might have been three—or even four—chicks in the nest at some point, but I never saw more than those two. 

The young osprey chicks’ heads only barely stick up above the sides of the nesting platform. More than 80% of occupied osprey nests in Wisconsin are found on man-made structures. Photo by Emily Stone.

Osprey chicks must grow fast. Newly hatched, they weigh only 1.8-2.1 ounces. By the time they fledge in 8 to 10 weeks, they’ll weigh between 32 and 64 ounces (that’s 2 to 4 pounds)! A diet of fish fuels that growth. To hunt, an osprey will hover above the water, peering into the shallows with sharp-eyed concentration. Although a dive may begin head-first, it ends with talons outstretched as they plunge into the water. Special scales and sharp barbs on their toes help them grip on to slippery fish. A reversible outer toe allows an osprey to carry a fish with its head facing forward, in the most aerodynamic position. With strong wings, they can carry fish up to about a foot long and about 4 pounds. 

The next time I spotted the chicks, they were clearly adult-sized teenagers. Buff tips on their dark feathers, dark streaking on their pale tummies, and red eyes gave away their age. Oh, and their behavior. One chick flapped awkwardly, ejected a mute (poop) over the side of the nest, and then hunkered down by Mom as if for a nap. 

Now too big and restless to hide down inside the nest, the juveniles showed up more regularly. On one long bike ride, I found an empty nest and a single osprey was hovering on the wind, swooping and doing acrobatics over the lake. When this aeronaut landed, their mottled juvenile feathers became visible. The youngsters were flying! An hour later, as I headed back past the nest, both chicks were at home. One of them was tearing fiercely at a large fish. A first catch perhaps? I didn’t expect them to grow up so fast!

Of course, migration is about to begin again, and virtually no ospreys will be left in Wisconsin by the end of October. The young ospreys will migrate alone, relying on instinct instead of parents to show them the way. And then they’ll stay there—in their warm wintering grounds—for two or three years before they return north to breed. 

I’m not quite ready to see them go. So, watching eagerly for that first glimpse of the nest as I biked along, I held my breath. A single osprey perched on the wooden nest platform. Zooming in for a photo, I quickly confirmed they were one of the red-eyed juveniles. It’s eight weeks after my first glimpse of their little heads. My schedule may have been disrupted this year, but the ospreys are right on track with theirs!

Emily’s award-winning second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at Or order it from our friends at to receive free shipping!

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 brand-new Mysteries of the Night exhibit. Connect with us on Facebook, Instagram, YouTube, and to see what we are up to.

Thursday, August 13, 2020

Signs of Fall

At the end of one of those perfect summer days—sunny and 75, with low humidity—I hopped on my bike for scenic ride along the east side of Lake Namakagon. A light breeze tickled the water, and brought to my nose the sweet smell of algae being tossed and turned at the surface. I scanned for otters among the thick beds of water lilies and purple-blooming thickets of pickerel weed. And then a glimpse of color caught me by surprise. I don’t remember what came out of my mouth. It was some garbled shout of startled dismay. There, in the corner of the bay, where the forest and marsh grass intermingled, stood a maple tree with every single leaf changed to red. 

This isn't the red maple I'm writing about (that photo taken from a moving bike didn't turn out) but it's another great example of a swamp maple turning early. 

I love fall. This year, though, I’m not ready for summer to be over. The Museum only just opened to the public, after pandemic-related delays in the construction of our “Mysteries of the Night” exhibit. My usual milestones of Loon Pontoon Tours, Master Naturalist Programs, our Summer Benefit Party, and Junior Naturalists playing games in the Outdoor Classroom were nowhere to be found. And now, already, by the first of August, signs of a changing season have appeared out of nowhere. 

Honestly, red maples catch me off guard every year. These adaptable trees can survive in both wetter and drier soils than their sugar maple cousins, but not without sacrifices. The soil in swamps is often low in essential nutrients. Unlike trees in richer soils, “swamp maples” can’t risk losing any nutrients to an early frost. Each year around the beginning of August, they pull valuable nitrogen and phosphorus back out of the leaves and into the twigs, where they’ll remain on-deck to fuel next spring’s leaf growth. 

Next, sugars in the leaves break down and form anthocyanins. Anthocyanins are pigments that absorb UV light, especially at low temperatures. Like sunscreen, they protect the leaf cells. They provide cover while swamp maples withdraw every last nutrient drop from fragile leaves. To create anthocyanins they need lots of sugars, which requires dependable soil moisture and sunshine. Happily, that’s the definition of a swamp.  

That red maple opened my eyes to other signs of fall I’d been trying to ignore. The dappled yellows in the roadsides show that the oval leaves of spreading dogbane and the lacey fronds of bracken ferns are following red maple’s example. While their yellows will soon drift to the ground, another one flashes upward. Yellow-shafted northern flickers are one of our only migratory woodpeckers, and right now they’re heading from Canada to the southern U.S. 

While on the ground, flickers’ smooth brown back with black bars and dots blends in well with soil and leaf litter. They catch ants and other insects with their long, sticky tongues. As they startle, handsome yellow feathers are visible under their wings and tails, and yellow feather shafts show through from above and below. Their white rump patches flash brightly and give another vibrant identification clue during short, undulating flights.

Once flickers lead your eyes to the edge of the woods, mushrooms start to materialize in the shadows, too. Along my driveway, the pure white blobs of Peppery Milkcaps have emerged from the netherworlds, still wearing little caps of pine needles and oak leaf duff. I’m always amazed by the way that mushrooms seem to appear out of nowhere after late summer rains. The Anishinaabe noticed this, too, and use the word “puhpowee,” to describe “the force which causes mushrooms to push up from the earth overnight.”

Peppery milkcap mushrooms aren’t edible, but that’s ok because my gardens are thriving. As I poked around the hops vines and ferns—still in my bike shorts and vest—I found several small, orange dragonflies perched in the waning sunshine. Once I’d identified them as female autumn meadowhawks, using the SEEK app, it became easy to discover that these are the one of the latest dragonflies to emerge from their aquatic childhoods each summer. The adults are unusually tolerant of cold, and withstand temperatures of 50 degrees F or lower as they survive into October and November. 

Also in my garden, I spotted a very fat monarch butterfly caterpillar. Will this one become a butterfly that flies to Mexico, or a monarch who lays more eggs and sends her progeny south for the winter instead? It’s around this time of year when the day length, temperature fluctuations, and worn-out milkweed plants trigger caterpillars to metamorphose into the “super generation” of butterflies. They will live eight times longer and travel ten times farther than their parents and grandparents. 

They’d better move fast. Already, our pollinator gardens have reached their peak, and some blossoms are beginning to fade. Out in the roadsides, the bright pink flowers of fireweed have bloomed their way up the stems with seed pods chasing close behind. A few have even burst open to reveal clouds of delicate fluff. “When fireweed turns to cotton, summer is soon forgotten,” they say in Alaska.

It’s a nice rhyme, but it’s not quite true, is it? These perfect summer days—with their colorful hints that fall is coming—are when we kick our memory-making into high gear. Every swamp maple we see dressed in its autumn attire is a reminder to enjoy the end of summer to its fullest and store up memories of sunshine for the long winter ahead. 

Emily’s award-winning second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at Or order it from our friends at to receive free shipping!

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 brand-new Mysteries of the Night exhibit. Connect with us on Facebook, Instagram, YouTube, and to see what we are up to.

Thursday, August 6, 2020

Butterflies are Weird

On one of those steamy, hot, and humid mornings last month I found myself staring out of my air conditioned office at the Museum’s vibrantly blooming pollinator gardens. Movement caught my eye, and I wandered outside with my camera and tripod to catch some of the action. By the end of the day, I had realized that butterflies are not only lovely, but really, really weird. 

As I’d hoped, a lovely orange butterfly was sipping eagerly from the pale purple bergamot flowers. Zooming in, I could watch as she probed the cluster of tubular flowers with her delicate proboscis. Except, calling it sipping isn’t quite accurate. 

A butterfly’s proboscis is more like a paper towel than a drinking straw. Like a paper towel absorbs water when even a corner touches the puddle of spilled milk, tiny grooves on the inside of the proboscis pull liquids upward using capillary action. The inner structure of the proboscis also breaks the column of liquid into tiny droplets that pose less resistance. 

Trying to suck the liquid up would require more force than the butterfly can exert, especially since butterflies don’t just drink thin nectar, they also consume water from puddles, juice from rotten fruits, animal tears, tree sap, and several other unexpected substances of widely varying thickness. As you might expect, different butterfly species have fine-tuned their proboscises to match their preferred food—even dried food.

Earlier this June, on a trip to Moquah Barrens, I snapped some photos of a dense mass of silvery checkerspot butterflies crowding around a lump in the sandy wheel track. What were they eating? A closer look revealed that the lump was a hairy, old wolf scat. Your first reaction to this might be a revolted “why?” Your next question might be “how?” Let’s tackle the “how” first. 

It’s actually pretty simple. Butterflies can send watery saliva down through their proboscis and onto the dry surface, where it picks up the substances they desire, and then travels back up the tube’s tiny grooves. Remember when we used to make Kool-Aid by adding water to powder? 

The “why” is a little weirder. Butterflies are drawn to the scat (poop) of carnivores, but also to mud puddles, rotting plants, and dead animals. Those gross things are a source of the nitrogen and sodium that are lacking in the butterflies’ usual diet of flower nectar. In most species, only males will “puddle.” He then passes these valuable nutrients on to a female when they mate so that she can use them to produce healthy eggs. It’s called a “nuptial gift.” I mean, who wouldn’t want a little packet of the essence wolf scat or mud puddle on their wedding day? Seriously, those are two of my favorite things!

Speaking of butterfly mating practices (I did mention that the day was hot and steamy?), the Museum staff got a good laugh last week when one of our volunteers walked across town just so she could impress us with the fact that “butterflies have eyes on their genitals!” That sent me down a Google black hole!

Well, technically they are simply photoreceptors that can detect ultraviolet light, not eyes that can see movement and shapes, but it’s still an impressive discovery (by accident) into the sensory world of butterflies. This research was done on the Japanese yellow swallowtail butterfly in 2001, but extraocular photoreceptors—light-sensitive structures that are found outside of an eye—occur in many animals. 

What’s the use of literally having “hindsight”? It’s different for males and females. They both have two small patches of photoreceptors covered by transparent cuticle. In male butterflies, the patches are located so that when he has successfully connected with the female during mating, the photoreceptors go dark. Once he knows his aim is true, he can deposit both sperm and a nutritious nuptial gift that also acts as a plug. 

In females, the photoreceptors aid in egg laying. The whole process takes at least three types of sensory organs! First, a female butterfly will use chemical receptors on her front legs to taste a plant and make sure it’s the right species for her caterpillars. Then she extends her ovipositor, and uses the two photoreceptors to tell her that it isn’t obstructed by a bit of schmutz, which would block light, and also eggs. Finally, as she pushes her ovipositor against the leaf, pressure sensors tell her that a leaf is really there, and she deposits an egg. 

The full story of the discovery of the photoreceptors is pretty fascinating, and I recommend reading the full article, “Hindsight of Butterflies: The Papilio butterfly has light sensitivity in the genitalia, which appears to be crucial for reproductive behavior,” by Kentaro Arikawa of Japan. 

The monarch who was (not sipping) on the bergamot flower fluttered away. I’ve always admired butterflies for their beauty and pollination services—but in hindsight—the weirdly elegant solutions they’ve found to life’s various problems are even more amazing.

Emily’s award-winning second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at Or order it from our friends at to receive free shipping!

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 brand-new Mysteries of the Night exhibit. Connect with us on Facebook, Instagram, YouTube, and to see what we are up to.