Thursday, August 22, 2013

Learning from the Lotus

Laughter and excitement filled the air as a group of naturalists and educators loaded into canoes at the Trempealeau National Wildlife Refuge in southwest Wisconsin. Off in the distance, the mighty Mississippi rolled by, with barges, pleasure boats, and runaways on rafts.
In the quiet backwaters, we pushed our canoes through thick patches of water lilies. We stopped to admire the pure white grace of a great egret before our commotion disturbed it into flight. Its short, circuitous flight ended on the branch of a dead tree, right next to the regal silhouette of a great blue heron.
Peering over the side of the boat, we caught sight of a water boatman swimming by. These small aquatic insects have long, flattened hind legs that work just like canoe paddles. Gazing skyward, we glimpsed the soaring specks of bald eagles, turkey vultures, and white pelicans over the far bluffs.
A thick patch of American lotus flowers caught our attention, and the canoeists converged on them for a better look. These water lily-like plants have huge, ten-inch diameter, pale yellow flowers that can rise six feet above the water on thick stalks. Platter-sized leaves, up to twenty inches in diameter, float on the surface or project above. This lotus is related to the sacred lotus, a powerful spiritual symbol of enlightenment, awakening, and rebirth in many cultures around the world.
As we paddled through the patch, I noticed something remarkable about the lotus. No matter how much I pushed the leaf under the mucky water with my paddle, the leaves refused to get wet or dirty.
This phenomenon isn’t unique to the lotus—you can observe it on your cabbage and broccoli, nasturtium, and columbine. Water beads up and rolls freely around their leaves. Jewelweed, a plant of moist woodlands whose juices may treat poison ivy, might be named for the beautiful silvery sparkle the water droplets make on its leaves.
The lotus is particularly good at staying clean and dry, though, and its secrets have been named the “lotus effect.” The lotus’s cuticle, or protective outer leaf covering, has a rough micro-topography made of soluble lipids in a matrix of wax.
Water has two main forces working on it at the same time: its attraction to itself, and adhesive forces that cause it to stick to surfaces. On smooth surfaces, those adhesive forces are maximized, but on the tiny wax mountains of a lotus leaf, it is easier for the water to stick to itself than to the air. Thus, the surface is water repellant, or “hydrophobic.” The water beads up and rolls off in the slightest breeze or tilt.
As the water scoots off, any solids it encounters (dirt, fungal spores, bacteria, algae, etc.) stick to the droplet more easily than to the leaf’s microtopography. The contaminants are carried away as the water droplets roll easily along. This is an excellent adaptation for anything living in the Big Muddy.
The hot sun beat down on our necks as we began to paddle back to the landing. A bit of orange caught my eye, and I turned just in time to see a small butterfly dance across the water. Butterfly scales are also hydrophobic, and their shape encourages the directional shedding of water. They can survive a rainstorm because their wings wick water away from their body, and refuse to get wet.
We turned to watch as a flock of ducks burst into the air. Bird feathers are naturally waterproof, although birds must preen constantly to maintain the integrity of their raincoat. While preening, birds coat their feathers with natural oils, and zip feathers together with tiny barbules that also provide a hydrophobic microtopography.
A hydrophobic surface is also useful for the water boatman we saw earlier. It uses a coat of tiny hydrophobic hair-like structures to hold water away from its body, so that it can breathe underwater as it hunts.
You might imagine that self-cleaning, un-wetable surfaces could be useful to humans, too. In fact, researchers have created self-cleaning house paint, self-cleaning coatings for textiles and clothing, and roofing tiles that all exhibit the “lotus-effect.”
When we borrow nature’s design principles to create more sustainable products and processes, it is known as biomimicry. The term was coined in 1997, by biologist and science writer, Janine Benyus, in her book, “Biomimicry: Innovation Inspired by Nature.” She writes, “Biomimicry is not about harvesting nature’s resources but about sitting at her feet as students.”
This group of educators and Huck Finn wannabes sure enjoyed nature’s lessons today.

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/


You Decide (or, Adventures with a Flying Squirrel)


A loud scratching inside the wall pulled me awake. The frantic scrambling was punctuated by minutes of silence, then more scratching. The clock glowed at 2:34 AM.

In my sleep-deprived stupor, I silently cursed Melissa Hogfeldt, Museum Intern, for bringing a rat into the staff house and keeping it in her closet without telling us. I tossed and turned, waiting for each new bout of scratching to begin, startling awake each time it did.

Finally, I moved out onto the couch and fell asleep in the gray morning light. When I stumbled downstairs for breakfast, Melissa was just heading out the door to bike to work. “Did you get a pet rodent?” I asked, clearly peeved, but trying to give her the benefit of the doubt. “No” she replied, obviously innocent, and confused. So I explained to her my sleepless night.

After lunch, when I called my dad to remind him to edit my Natural Connections article, I complained about my awful night. “I bet it is a flying squirrel,” he said, “at night, in the summer, up north...it must be a flying squirrel.”
Flying squirrels are amazing little rodents. They don’t actually fly, but glide on a flap of skin, called a patagium. It stretches between their front and hind legs, and is held out wider by an extra bit of cartilage on their wrist called a styliform. These three-ounce acrobats can turn 90 degrees around an obstacle in the air. A flip of their thin, flat tail changes their trajectory upwards for a smooth landing.
Immediately after landing, the squirrel will run to the other side of the tree trunk, just in case a predator spotted it in the air.  Fascinating as these critters are, I almost wished I was a flying squirrel predator (a club that includes weasels, coyotes, foxes, and many more) after my short night!
After a failed attempt at an afternoon nap, I started making dinner. Mmmm…chanterelles…freshly gathered from the woods. Mycophagy (eating mushrooms) is one thing I have in common with flying squirrels.
In the Pacific Northwest, flying squirrels eat fungi and lichens almost exclusively. Many of the species they prefer are truffles, which fruit underground and release a strong scent when ripe. Therefore, surprisingly, the flying squirrels spend a considerable amount of time rooting around on the ground. Then, just as a black bear spreads berry seeds, the squirrels excrete fungal spores.
Many of the fungi the squirrels eat are mycorrhizal species that live on tree roots and assist the tree in acquiring nutrients and water, while receiving sugars from the tree’s photosynthesis (myco=fungi and rhizal=root).
The squirrels are so good at spreading spores, and the fungi are so important to the trees, that flying squirrels are considered “keystone species” in the Pacific Northwest. This simply means that they have disproportionately large effect on their environment relative to their abundance.
Although flying squirrels and their ecological relationship have not been well-studied in Wisconsin, we can assume that they fill a special niche in the Northwoods, too. We do know that Wisconsin flying squirrels have a more varied diet, which includes nuts, seeds, fruits, berries, insects and bird eggs.
As I finished frying up my mushrooms, Museum Intern Kellie Solberg joined me in the kitchen “Did you find your rodent yet?” she asked, “because I think I did…in the toilet.”

His little pinkish-gray nose with long whiskers just broke the water surface, while pink ears floated erect in the porcelain bowl. His long, flat tail extended down the tube. On the seat were muddy footprints. Below the ceiling vent, the floor was scattered with rodent-chewed frass. RIP, little guy.

Normally, Northern flying squirrels like to nest in cavities in live trees in older forests. The live branches and leaves must provide better cover than the bare branches of snags, and a home site they like will stay standing longer if they choose live over dead wood. If good tree cavities aren’t available, squirrels may even nest in the tangled mass of a “witches broom” growth in a spruce tree, or they will build a leafy nest, or “drey,” similar to gray squirrels.

I suppose an opening on our roof looked like a good cavity, and this squirrel decided to include our house in its den rotation. Now, it resides in our salvage freezer, awaiting taxidermy.

As mad as I was about my sleepless night, I’m sorry about the way it all ended. Northern flying squirrels are a “species of special concern” and a protected wild animal in Wisconsin. They may be locally abundant, but are not widespread. If you see one in the woods, count yourself lucky!  If you see one in your toilet, well, I’ll let you decide.

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/.

The Kingdom of Fungi

We explored a magical kingdom yesterday...a kingdom filled with mystery, danger, humor, healing, and beauty. It is the kingdom of fungi.

Our mushroom foray guide was Britt A. Bunyard, PhD, Publisher and Editor-in-Chief of FUNGI magazine. He gave some quick hints for collecting mushrooms: never use plastic bags, use a knife to dig up the base of the mushroom, and learn your trees. Plastic bags will make the mushrooms sweat and spoil your dinner; the mushroom’s base may hold the key to its identification; and certain species of fungi prefer certain species of trees.

The woods at the Forest Lodge Nature Trail, ten miles east of Cable, WI, are mixed with such a hodge-podge of trees, that we simply spread out to scour the whole area. The roots of an pine might be sprouting mushrooms near the base of a maple, while the interspersing dead wood and moss hold a variety of mycelia with the potential to grow many species.

Soon the contents of everyone’s baskets and bags created a rainbow of fungi on a picnic table at the trailhead. Instead of starting with the brilliant orange and yellow specimens, where all of our eyes focused, Britt held up a large, drab, chunk of oak bark. Mysterious black shoestrings clung into the furrows on the brown slab. “These are the rhizomorphs of the honey mushroom.”

The honey mushroom uses rhizomorphs to spread and infect live trees, live and dead roots, and stumps. The stringy, black, root-like rhizomorphs can grow at a rate of one meter per year, and transport a fungus that can girdle a tree and kill it. The mycelia, (the vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae) can lie hidden for years, before bursting forth a cluster of choice-edible mushrooms.

Just don’t mistake the white-spored honey mushroom for the dark-spored, aptly named, deadly galerina. Death from mushroom poisonings is less common than shark attacks, but Gary Lincoff, author of the National Audubon Society’s Field Guide to North American Mushrooms, cautions that “Any mushroom is edible once.” The danger of eating wild mushrooms is sometimes played down by experts. True, only a couple species will actually kill you, but I think the pros love the feeling of defying death through their own wit and expertise.

To caution us further, Britt pulled another chunk of bark out of his basket, this time with a group of small, globular, light brown fungi attached. “Who recognizes these?” he challenged. “Puffballs!” several of us exclaimed, excited to see an edible we could identify. While somewhat bland, many folks love them fried in butter and garlic.

“No!” interjected Britt, “and this one could kill you.” Deaths from the common earth ball, Scleroderma citrinum, are rare, but it does cause severe gastric upset. The tough, scaly skin on these small, rounded, stemless mushrooms makes them look a little like old potatoes. Descriptively, it is sometimes called the “pigskin poison puffball.” Britt whipped out his European-made mushrooming knife and sliced the earthball in half. A thick rind of a slightly different shade of white surrounded whitish flesh, but in the center was a hard, inky purple stain.

If you’ve eaten the true puffballs, you know that the center must be pure white and undifferentiated.  If not, you risk eating a disgusting puffball past its prime, or a poisonous look-alike. True puffballs, like the one we thought Britt was showing us, release their spores through a single opening in a cloud of greenish-gray dust. Perhaps this is where the earned their scientific name--Lycoperdon pyriforme. In Greek, “Lyco” means wolf, “perdon” means fart, and “pyriforme” means pear-shaped.  It is a pear-shaped wolf’s fart puffball. Who said mycologists don’t have a sense of humor?

While laughter may be the best medicine, some mushrooms are almost miracle cures in themselves. The chaga, a pathogenic mass of fungal tissue and wood from its birch tree host, is purported to have compounds that can be used to treat cancer, HIV, and diabetes.

The ugly black and rust-brown mass of the chaga contrasts with the delicate earth-toned rainbows of turkey tail fungus. We found a log filled with remains of last year’s dried and crumpled crop. Soon, with fall rains, the common polypore “bracket” fungi, found throughout the world, will sprout anew. This little wonder has been shown in clinical studies to improve cancer patients’ immune systems after chemotherapy. When my Aunt Nan was battling uterine cancer, she put little ice cubes of turkey tail tea into all her food.

Some mushrooms heal us just with their unexpected beauty. Shining like jewels, brilliant orange waxy caps poke their tiny heads out of soft moss. Nearby, the scarlet caps of Russulas sit atop pure white stems. Under the bark of a tree, a “green elfcup” fungus leaves its turquoise stain on the wood.

In her poem, “Mushrooms,” Mary Oliver writes: “astonishing in their suddenness, their quietude, their wetness, they appear on fall mornings…those who know walk out to gather, choosing the benign from flocks of glitterers, sorcerers…

Ah, that magical kingdom of fungi...

Have you ever smelled a garter snake?

Have you ever smelled a garter snake? A foul, sweetish odor permeated the screen porch and clung to my hands as we passed the small snake around. The scent is a defense mechanism that makes garter snakes less appetizing to potential predators.

The twelve middle-school kids on our field trip were not deterred, though, and the snake calmed down as we examined it. One student in particular was reluctant to pass the snake on, and watched, mesmerized, as the yellow and black creature twined around his hands, and even slithered up his sleeve.

My first clear memory of a garter snake is from fourth grade, when Clayton County Iowa Naturalist, Karen Newbern, gave a program in the school library. There, on the pea-green, low-pile carpet, the snake pooped. It reminded me of a cheeseburger.

Snake feces is a lot like other animal waste. It smells, it is often brown, and it happens as often as the animal eats. Because snakes only have a single utilitarian opening called a cloaca, their poop combines with urea from their kidneys. It is the same with bird poop, where you see the purple berry seeds mixed with white urea. This particular snake had yellow urea that looked just like melted cheese, along with a brown chunky center.

Today, as we examined the garter snake, retired zoologist and Museum volunteer, Ed Moll, reminded the kids to hold the snake carefully with two hands. Garter snakes are not constrictors, so they don’t squeeze your hands and hold on like bull snakes or fox snakes.

Constrictors have strong muscles they use to squeeze their prey to death and then eat it, but garter snakes simply seize prey in their mouth and work it down. This is where their poop starts – as a rodent, frog, slug, earthworm, leech, lizard, amphibian, ant, cricket, frog egg, or toad. Garter snakes are carnivores and generalists. They will eat almost anything they can overpower.

While their musk protects garter snakes from predators, three features of their mouths make it easier for them to be the predator. First, garter snakes have an extra bone between their skull and lower jar. That bone allows their mouth to open one hundred and eighty degrees. Second, the two halves of their lower jaw are not fused, and can move independently. Finally, their teeth point down their throat.

So, a garter snake can open up wide enough to let a toad in, then walk the critter down their throat by using one side of their jaw at a time. Then their ribs flare and their skin stretches to accommodate the breakfast bulge.

If attempting this with a live and wiggling prey sounds daunting, you may be interested to know that garter snakes (although often thought of as non-venomous) have a little venom to assist with the process. The venom is in their saliva, and seems to flow only after a bit of chewing. The mild toxin helps to stun their prey, and is not usually dangerous to humans, unless you are bitten repeatedly and develop an allergy.

After prey is in their belly, snakes will go into a dormant mode, and expend as little energy as possible on things other than digestion. Optimal digestion occurs at 86 degrees Fahrenheit, as stomach enzymes break down all but the bones, teeth and feathers of their prey. These hard parts will be excreted as waste, and evidently, sometimes look like a cheeseburger.

Despite the musky smell on Ed’s screen porch, the students sat mesmerized by the snake and its amazing adaptations. Until, that is, one parent chaperone called it a garden snake. “There is no such thing!” exclaimed Ed, breaking their trance with a good-natured shout. Hopefully that lesson will linger as long as the garter snake’s smell.