A Snowshoe Field Trip

The winter woods rang with the chatter of thirty or so third graders on a snowshoe field trip. Bright spring sunshine buoyed all of our spirits. This was my last group in a two-day marathon that brought 120 students and their teachers from Hayward, WI, out hiking on the North End Mammal Trail.

Along the 1.1 k Ridge Trail loop, just south of Cable, the Museum has placed about 20 life-sized wooden silhouettes of local mammals. The animals were cut out by students at Drummond High School, and their features were wood burned on by Museum volunteers, including local artist, Donna Post. We’re partnering with the North End Ski Club. Soon, we’ll also have a self-guided trail booklet with facts about each mammal.

Today, though, I had two backpacks full of wolf and fox furs, track molds, and a deer leg to teach the kids about winter adaptations of animals. At the top of the first big hill, I stopped to let the tail of the line catch up. “This is the best field trip ever!” exclaimed one student. “I’m not going to make it,” countered a short-legged snowshoer with a dramatic flop into a snowdrift. I reminded them to keep eyes and ears open, like wolves on a hunt, as we continued single-file, pack-like, down the trail.

“What’s that?” “A fake wolf!” “No, it’s a bear.” I chuckled at the conversation behind me in line. We stopped by the first visible mammal cutout (the chipmunk at the first station was completely buried in snow-- “hibernating”). Pulling out the wolf pelt, a wolf track mold, and a deer foot, we talked about the advantages and disadvantages of big feet. Appropriately, March is the “snow crust moon” in the Anishnaabe culture, and this gives a huge advantage to wolves with big feet over deer with small pointy feet, just like snowshoes help us humans stay on top of the snow.

A little farther on, my entourage spotted a flying squirrel attached partway up a hollow tree. These little nocturnal mammals have a fun behavioral adaptation for staying warm in winter – sharing body heat by snuggling together in groups of twenty or more. We did our own experiment, huddling in groups of six or so kids. I gave each cluster a thermometer and they had to try to get it as warm as possible. In just ten seconds they raised it ten degrees above the air temperature!

At another stop, we talked about the hunting strategies of long-tailed weasels. Like the small mammals they eat, the weasels spend a lot of the winter in the subnivean zone--in the air pockets and tunnels that open up at the boundary between earth and snow. Stored warmth from last summer’s sun radiates out all winter, and is trapped by the insulating snowpack. This helps to melt little chambers in the snow, and keeps the subnivean zone at a balmy 32 degrees.

I pulled two weasel furs out of my pack, and we all admired the excellent camouflage of their summer-brown and winter-white coats. Students pulled off their snow-crusted gloves to feel the amazingly soft fur, and we exclaimed at how skinny these creatures are – all the better for following mice into their burrows!

Then I asked the students to try and find the subnivean zone. A comical flurry of digging ensued, with colorful stocking caps disappearing down into holes. We never found the ground under all this snow, but we did discover an interesting series of icy and fluffy layers with different snow textures in the snowpack.

The wooden cutout of the black bear was easy to find, and students were eager to share their knowledge about bears. “What do you know?” I asked. We talked about mamma bears having their babies during hibernation, and male bears being more impatient to leave their dens in the spring. “So this bear must be a male,” observed one student.

My question “what do bears eat?” brought many answers. “Humans?” Well, no, but berries, fish, honey, insects, deer (fawns), seeds, and garbage to name a few. “So what’s that called,” I asked, “when an animal eats both plants and meat?” “Omnivore!” came the answer. Then we compared humans, with our omnivorous diets, to bears. I had the students feel their flat molars with their tongues. Those teeth are for grinding up carrots sticks, and bears have flat back teeth, too. Then we ran our tongues over our sharp front teeth. Bears also have sharp front teeth for tearing off bites of meat.

Finally, we ended up at the silhouette of the red fox. We talked about their fluffy, scarf-like tails, warm fur, and excellent hearing. Like owls, foxes can hear mice under the snow, triangulate their position, and pounce. Amazingly, scientists in the Czech Republic and Germany have discovered that foxes are more successful at catching mice in tall grass or snow if they face north to hunt. Over seventy-two percent of successful attacks were made when the fox was facing north, and foxes were also somewhat successful when they faced due south. Attacks from other directions were largely unsuccessful.

Why is the big question, of course, and scientists still don’t know for sure. “If you grow up to be a scientist,” I suggested to the line of bright-eyed explorers, “you could help figure it out!”

Whether or not any of them will grow up to be scientists, I have no idea. But at least we had a positive experience in nature that may inspire them to continue exploring and protecting the woods for years to come.

“To love what we do and feel that it matters – how could anything be more fun?” –Katharine Graham

For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI, at 13470 County Highway M. The current exhibit, “Deer Camp: A Natural and Cultural History of White-tailed Deer,” opened in May 2013 and will remain open until April 2014.

Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com

Welcome Theo!

“Who’s awake?  Me, too...” I love to hear the deep, powerful hoots of a great horned owl billowing through a snowy forest. Their stuttering rhythm -- hoo-h’HOO-hoo-hoo – seems to ask the question, then offers a conspiratorial answer.

I usually hear great horned owls in early winter, as they form pair-bonds and defend territories in preparation for nesting season. These large owls don't build their own nests, but take over nests made by crows, squirrels, hawks, or herons--whether their previous owners were ready to move out or not.

In late January and February things quiet down as the larger female owl lays from one to four, but most often two, eggs. She must begin to brood immediately, and then for the full 35 day incubation period, so that the eggs don’t freeze. Because of the necessity of constant brooding, great horned owls have a very strong pair-pond, and the attentive male brings food for the female, and eventually the chicks.

Why must owls nest in the depths of winter? It takes a long time for the owlets to grow up, and they require parental care well into July. If the owls waited until June, like the smaller birds, the young owls would not be strong enough before the next winter.

Just thinking of a 3 ½ pound owl, right now, sitting in a snow-covered nest with eggs or young chicks, makes me feel cold. But the owls are tough.

Excellent eyesight, precise hearing, and silent flight make great horned owls intimidating nocturnal predators. Their super strong talons (reported to crush prey with a force somewhere between 30 and 300 pounds per square inch) allow them to hunt such formidable prey as porcupines, geese, and scorpions. Speaking of tough, they are the only regular avian predator of skunks.

From their place at the top of the food chain, the only things great horned owls have to worry about are territorial disputes with each other, eagles, and snowy owls. Oh, and those pesky crows. Great horned owls are crows’ most dangerous predators, but if crows find an owl during the day, they will flock to it and harass it with the safety of numbers. One author hypothesizes that the long hours of darkness during their breeding season helps to protect the owls from crow harassment.

As tough as they are, owls do have one more predator to worry about – humans and our vehicles. Road ditches – where trees for perching meet grass with small rodents – are tempting places for owls to hunt. When you throw your apple core out the window, it attracts even more rodents, which lure  even more owls. Unfortunately, when an owl is focused on its prey, it won’t notice your headlights closing in.

Most of the Museum’s collection of owl specimens were picked up on the side of the road. Their wings and feet make great educational tools, but we’d much rather have live birds in the wild.

Not every car-owl collision ends in the salvage freezer, though.

Last summer, Joe Papp, a Museum volunteer who has experience with raptors, noticed a great horned owl in the ditch along Highway 63, just south of Drummond, several days in a row. When Joe was finally able to catch the owl, it was obvious that its wing was injured, and the owl couldn't fly.

Well, Joe brought the owl to Katie Connolly, our Museum Naturalist/Curator, and she delivered the owl into capable hands at the Raptor Education Group, Inc., in Antigo, WI, where they have licensed rehabilitators.

“Unfortunately his wing had been broken at a joint, and had already begun to heal, leaving him crippled and unable to fly ever again,” Katie told me. “The rehabilitators believe he was struck by a car on Highway 63 and began eking out a living next to the roadside because he couldn't fly away. We can only imagine him running down mice and other rodents to eat!” she added with a chuckle. That’s just one more example of owl toughness.

Because the owl can’t fly, he wouldn't have a fair shot at surviving in the wild, and is non-releasable. Six months after the accident, the male great horned owl, now named Theo, is safe and well fed in his home in the raptor mews at the Cable Natural History Museum. With Katie as his trainer, Theo will soon be an education bird who can help kids of all ages learn about the amazing adaptations, and toughness, of great horned owls.

We’ll be posting updates about Theo’s training progress, construction of his new home in the Museum’s outdoor classroom, and public programs where you can meet him, on our website (www.cablemuseum.org) and Facebook page.

While you wait to meet Theo, don’t forget to keep an eye—and an ear—out for his wild cousins. Who likes owls?  Me too.

For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI, at 13470 County Highway M. The current exhibit, “Deer Camp: A Natural and Cultural History of White-tailed Deer,” opened in May 2013 and will remain open until April 2014.

Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com

A Walk Through the Summer Woods

I’m going to take my imagination on a walk through the summer woods. Would you like to come with me?

The day begins with a cacophony of birdsongs, crashing through my bedroom window. Robins shout “Cheer up, cheerily, cheer up, cheerily” on incessant repeat. Northern parulas buzz up a scale, then alternate with a call that sounds like Porky Pig’s classic “Th-th-th-th-That's all, Folks!” All the while, the blue-headed vireo announces his presence with short, loud phrases: “See you. Be seeing you. So long.”

Soon, bright sunshine follows the birdsongs into my room. “Hello, sun in my face.

Hello, you who make the morning…and spread it…into the windows of, even, the miserable and crotchety,” muses poet Mary Oliver. Rolling over, I look at my watch: 5:30 a.m. I wipe the sleep out of my eyes and put on shorts, a tank top, and hiking shoes. After all, Henry David Thoreau claims that “An early morning walk is a blessing for the whole day.”

Sunshine glows through vibrant green treetops, and dew clings to the grass as we grab our binoculars and head down the driveway. In the big maple tree, we can hear the northern parula buzzing away. First I listen, tilting my head like an owl or a fox for better triangulation. When I think I know where he is, I lift my binoculars to my upturned eyes and search for the little singer.

The sun, rising higher, begins to feel warm. There! A sunbeam catches his gorgeous blue head, yellow throat, and…OW!!! Binocs slam to my chest as I swat three mosquitoes that simultaneously penetrate the skin on my neck, my eyebrow, and my lower lip. Time to get moving.

We cross the road and duck through a gateway of little hemlocks onto the trail. The cool shade feels good since elsewhere sunbeams and dew have combined to raise the heat index. Sun flecks play on the forest floor, highlighting tender green leaves pushing up through last fall’s brown carpet. A patch of bunchberry flowers glows white in the diffuse light, and I hurry toward them for a closer…aaarrrrgh!

My face went right through the sticky net of a spider web. Clinging strands send shivers down my spine, and delicately tickle the nerves of my nose, cheeks, hair, and neck. Not far from my right ear, I notice the web owner herself, looking fairly large and not so happy with me. Every night, orb-weaver spiders like her eat, recycle, and re-spin their webs using only their sense of touch. I just ruined a work of art that took hours to create.

Forgetting the bunchberry, we forge on, still picking spider silk out of our hair, and also swatting mosquitoes. Naturally, they land almost out of reach on the backs of our arms, between our shoulder blades, on ankles and knees. These are female mosquitoes looking for a blood meal. Once satiated, they will rest for a few days to let the blood digest and its nutrients (our nutrients!) develop into eggs. After just two or three days, they will lay those eggs and look for a new blood host. The cycle repeats itself until the female dies. On average, each female lays 200 eggs during her short life.

More spider webs lie in wait across the trail, so I pick up a stick from the moist duff to wave in front of us. The swinging stick keeps most of the webs off my…ewww! Something squishes under my fingers, and I feel sticky slime coat my skin. Turns out, my spider-stick was also the home to a small slug. I rub my hand in the dirt to get rid of the slimy feel.

Soon we emerge from the deep shade of the forest into an emerald green field. Wild roses bramble along the edge between forest and field, the purple canes of blackberries are dusted with five-petaled, snowflake-white flowers. “There were violets as easy in their lives as anything you have ever seen or leaned down to intake the sweet breath of…” (Mary Oliver) They cluster in the grass at the edge of the trail, their purple faces delicately fringed with white beards.

As I rise from smelling the violets, I notice something on my shin. A tiny nymphal black-legged tick (aka deer tick) is crawling up my leg. Actually, two…no, three little ticks had quested right onto my ankle. It is amazing that I even noticed these little disease vectors, since they are just the size of a poppy seed.

Flicking off the ticks, and frantically brushing at any suspicious tickle, we hurry down then trail, suddenly sweating profusely in the sweltry heat. It has become so hot that even the birds have stopped singing.

And here, my friend, is where I will part ways from our imaginary field walk. The grass may be greener in June, but green grass isn’t everything. Right now, today, in March, there is clean, white snow covering the ticks. Some mosquito adults hide out in diapause—a state of suspended animation—while the larvae of other mosquito species are trapped beneath several feet of lake ice. The orb weaver died last fall, after creating a thick, silken sack for her eggs. As for me, it is twenty degrees, the sun is out, the bugs are gone, and I just bought new skis! Carpe diem!

“Now comes the long blue cold. And what shall I say but that some bird in the tree of my heart is singing.” –Mary Oliver

For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI, at 13470 County Highway M. The current exhibit, “Deer Camp: A Natural and Cultural History of White-tailed Deer,” opened in May 2013 and will remain open until April 2014.

Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com

Surrender

You probably know the drill well. First I pulled on the long johns, then the thick wooly socks, snow pants, a wool sweater, windbreaker, wool hat, ski boots, and—finally—puffy mittens. With a quick look at the thermometer (-5°F), a short drive to the trailhead, boots in ski bindings, hands through pole straps, and I was off!

Bright sun sparkled merrily over the rolling hills as I shushed along, working hard to glide over the cold, hard snow. In no time, I’d warmed right up, and my core temperature felt more like July than January.

Humans have gotten used to a tropical climate over the millennia, and we try to recreate it wherever we go. Whether it’s a wood stove crackling cheerily, our metabolisms burning edible fuels, the car heater turned on full blast, layers of wool, down and fleece trapping warm air around our bodies, or a trip to Florida, we tend to survive the winter by avoiding the cold.

Not everything has that luxury. Clinging to the bark of almost every tree in the forest is an organism that does just the opposite. “Lichens master the cold months through the paradox of surrender.”writes David George Haskell in his wonderful book The Forest Unseen. He compares lichens to the Taoist story of a man who jumps off a waterfall and, to everyone’s amazement, returns safely to shore. When asked how he did it, the old man answered, “I go down with the water and up with the water...I survive because I don’t struggle…”

Lichens don’t fight the cold, dry, winter air. Unlike wintergreen leaves, they have no waxy coating to slow evaporation. They don’t hide roots deep in the unfrozen ground like the oaks. They don’t try to fire up their metabolism to produce internal warmth like the chickadees, and they don’t grow layers of soft fur to retain it like the ermine.

Instead, lichens allow themselves to gain and lose water as the relative humidity fluctuates. During dry spells, a lichen thallus (leaf-like structure) might only contain 15-30% water, and it goes dormant. Freezing temperatures don’t seem to bother them, and at least one species can even photosynthesize at -4 degrees F. In fact, lichens have survived at least eighteen months in the hostile environment of outer space. While orbiting the Earth on the outside of the Space Station, lichens experienced wide temperature fluctuations and the full intensity of UV rays from the Sun. Back on Earth, given water and sunshine, they began photosynthesizing with no residual effects.

On a warm, damp day, the lichens I skied past will do the same thing. Their dusty-green, opaque surfaces are filtering out sunlight today, to protect inner cells from sunburn. But, with as little as 60% relative humidity, moisture will seep back into their cells, the surface will become translucent, and photosynthesis can resume within minutes.

“Plants shrink back from the chill, packing up their cells until spring gradually coaxes them out. Lichen cells are light sleepers. When winter eases for a day, lichens float easily back to life,” writes Haskell.

This incredible flexibility to surrender to ambient conditions makes lichens excellent colonizers of harsh environments. On mountaintops, the tundra, fresh rock faces, gravestones, and even mine tailings, lichens are the first signs of life. Vegetation dominated by lichens covers nearly eight percent of the Earth, largely in the Arctic tundra. What makes them so tenacious?

Lichens are actually a partnership between two or three different types of organisms. They are a cross-kingdom alliance. A fungus plays host, providing a stable home for a photosynthetic partner. Algae or cyanobacteria (formerly known as blue-green algae) set up shop inside the leaf-like structure, and use the Sun’s energy to make food for them both.

Without the photosynthetic partner, the fungus could not grow in rocky habitats that lack organic matter to decompose. When scientists try to culture the fungus by itself, they end up with a slow-growing lump. Without the fungus, the algae would be severely restricted in is habitats as well, needing constant moisture to survive and reproduce.

Together, the fungi and algae in lichens are the quintessential example of a mutualistic symbiosis, where both partners benefit from a close, living relationship. Lichens are also a lesson in Taoist philosophy, exemplifying the concept of “Wu Wei,” that was demonstrated by the old man in the waterfall. Wu Wei means allowing things to flow naturally, without combative or egotistical effort.

A good skier can use Wu Wei as well. Extending the glide, relaxing on the back swing, using momentum, and coordinating movement and breath are all hallmarks of great technique. My more casual technique also includes pausing to enjoy the view (and catch my breath) at the top of a hill, smiling at the bright pink sunset, and finding inspiration in the winter woods.

For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI, at 13470 County Highway M. The current exhibit, “Deer Camp: A Natural and Cultural History of White-tailed Deer,” opened in May 2013 and will remain open until April 2014.

Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com/.