Green Islands

Leaves fell like glitter on the sun-showered path. These tiny yellow hearts of quaking aspen fluttered wildly as they descended, eventually ending in drifts built upon the wilted bodies of their companions. Placid raindrops beaded up on their slick surfaces, shining like jewels in the slanting rays of afternoon sun. A gentle sweetness wafted on the lukewarm breeze.

I do love fall.

And yet I already miss (just a little) the vibrancy of a buzzing summer day. Maybe if we could hold on to that green energy for just a little longer…

The golden leaves almost all had their own little hitchhiker hiding out between those slick, waterproof leaf-skins. My evidence? Bright green trapezoids of chlorophyll trapped between the first and second veins on one side of the leaves’ midribs. You may assume that the aspens are simply showing their support for the Packers. I have no evidence to discredit their status as cheeseheads, but the trees are not responsible for the variegated leaves.

A small, brown moth with white-fringed wings laid an egg on the leaf petiole (stem) back in July. By September, a translucent larva hatched and bored into the petiole, causing the stem to swell a bit into a small gall. Munching its way up inside the leaf under the cover of darkness, the larva interrupted the mechanisms the tree normally uses to draw chlorophyll out of the leaf during the waning days of autumn. The result is a “green island” in the yellow aspen leaves, and a forest carpet of Packers’ colors.

Such a tiny caterpillar would dry out in the summer heat, or if it tried to pupate high in the tree canopy. Instead, it takes advantage of pleasant fall weather, and then hitchhikes on the falling leaf down to the damp forest floor. Once there, it steals a few more bites of the green energy it preserved, and then pupates in relative safety and an agreeable microclimate. The soon-to-be-moth spends the winter in its cocoon, which is loosely woven to the surface of the now-brown leaf.

The receding snow and warming sun of May stimulate metamorphosis, and the new moth emerges from its winter sleep.

While apparently unstudied in the U.S., this drab moth and its tiny caterpillar have a Holarctic distribution. This means that they live across all the continents in the Northern Hemisphere. In fact, some of the information I have presented here was translated from Swedish and Dutch by the magic of the Google Translator! I can track this organism throughout the world by the universal language of scientific names. Ectoedemia argyropeza may not roll off your tongue, but scientists all over the planet use this one name to refer this particular species.

Whatever you call it, the vibrant green islands those moth larvae preserve are a lovely part of fall.

The Season when the Sun Shines Up from the Ground

This is the season when the sun shines up from the ground. The golden leaves of birch, maple, and aspen now carpet the forest floor, and reflect a special glow even on gray and rainy days when dense clouds hide the real sun. The sweet smell of damp, decaying leaves reminds us that they were sugar factories all summer long, making food out of thin air.

From the feel of chilly morning air pouring into your lungs, to the nostalgic smell of wood smoke, and the tinkle of skim ice breaking, fall is a season for the senses. Harsh and exciting calls from wild geese rise above leafless, bony gray twigs, and drift down to our ears with the first flakes of snow. Those fallen leaves crunch and rustle underfoot. At dawn, they sparkle with a rime of fairy-dust frost, then darken and molder slowly into a soggy wet mat as the sun softens the frost and starts the biological engines of decay chugging.

This is also the season for MuseumMobile programs, and several times a week I visit local schools for a full day of teaching in the classroom. I share a 30-45 minute nature lesson with each classroom of kindergarten-through-sixth graders. We talk about things like symbiosis, coal formation and mining, owl adaptations, food webs, tree parts, and spiders.

The kindergarten lesson is one of my favorites. Excitement stirs in the children as soon as I enter the room carry a large tub. “What’s in there?” They can’t wait to see! We talk briefly about exploring nature through our senses, and point to our eyes, ears, nose, mouth and tongue, reviewing just what those five senses are. Then I pass around a screen-covered sniffing-cup full of white cedar needles, and three cloth bags filled with various natural items from the Museum’s collection for the students to explore only with their sense of touch.

What fun to watch their eyes light up as they recognize a deer antler by the smooth feel of the bone! Little noses scrunch up to help eyes stay shut to keep from peeking. Sometimes excitement gets the best of someone and they blurt out the name of the object. They are just so proud to know something about nature! Five year olds here in our beautiful Northwoods know more about nature than the twelve-year-olds I used to teach from inner city San Francisco.

The grand finale of the kindergarten lesson is the snapping turtle shell. Bigger than my popcorn bowl, its shiny brown scales are fun for little fingers to rub and explore. We look at its backbone, and feel our own vertebrae, too. Then, everyone gets to be a turtle!  One by one I place the shell on the back of a huddled student, and announce “Bobby the Turtle!” and then “Susie the Turtle!” to a swarm of their giggling friends. As the “turtle” beams up at me with the joy of fun and natural connection lighting up their eyes, I think again: this is truly the season when the sun shines up from the ground.

 

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.

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/

Curiosity

Bright summer sunlight trickled through the thick canopy of trees and danced across the shallow stream. Two dozen little feet clad in their oldest shoes tramped through the water, too, somewhat less gracefully than the sun flecks. This was crick stomping at its best: a hot day, cool shade, refreshing water, and a sense of adventure.

I felt like a mother hen at the center of the flock as we moved our way upstream. Instead of pecking at grain, the chicks’ hands darted out to pick up this rock or that one. I was always glad when my campers got as excited about rocks as I did. The shallow, flashy, nature of the creek meant, on most days, several shallow channels braided themselves through wide gravel bars of interesting rocks. After big thunderstorms, I loved to watch as a torrent of brown water churned and frothed down the creek, revealing an alien landscape to explore as the floodwater receded.

On this particular crick stomp, we brought an honored guest with us. A NASA scientist named Owl (a camp name chosen because she liked the nighttime) was in the creek with us. She was part of a NASA outreach program involving girls, science, and education. She led us in activities like using recycled items to create creatures that could survive in each planet’s unique habitat, dissecting candy bars as if they were types of bedrock, and stargazing.

As an astrogeologist, Owl was particularly excited to accompany the girls on a crick stomp. They were soon distracted picking up rocks, but I stuck by Owl and let my curiosity show.

“Look here,” she said, pointing to a place on a gravel bar where flattish rocks were stacked up against each other like shingles. “When we see rocks like this, we know that water once flowed there.” “Obviously,” I thought in my teenage head, “this is a creek.” Owl continued: “By learning about rocks on earth, we can also learn more about rocks on other planets. If we see rounded rocks, or rocks stacked up like this on other planets, we know that there was once water flowing there also.” “Hmmm…” I thought, and tucked that bit of knowledge away in my brain.

As I went on to take geology courses in college, Owl’s words snuck back into my consciousness time and again. In class, we often talked about how you could read the story of ancient streams in the structure of the bedrock they had become. Knowing this gave me new eyes for observing flowing streams and the rocks they move.

This summer, I was barely aware of NASA’s latest project – the Mars rover “Curiosity,” until a friend (also a geology major) posted a news article on Facebook. The headline read: “NASA's Curiosity Finds Water Once Flowed On Mars.” The detailed photos showed rounded pebbles and streambed characteristics that could only have been formed by running water.

Scientists gathered enough data to estimate that the stream was between ankle and hip deep, and flowed about three feet per second. The characteristics of this Martian stream are preserved in a conglomerate, the type of rock formed when pebbles and sand become cemented together. You can find earthly conglomerate nearby at Copper Falls State Park.

Reading NASA’s report, I was immediately transported back to crick stomping with Owl in our shallow stream. “By learning about rocks on earth,” she had said, “we can also learn more about rocks on other planets…we can know that there was once water flowing there also.” Thanks to Owl, and a little Curiosity, the alien landscape of Mars seems a lot more familiar.

At the time Owl visited, finding evidence of surface water on Mars was a lofty goal for the future of space exploration. Now that the future is here, I wonder what the next generation of space exploration will look like, and if any of those crick-stomping girls will join the adventure.

Sumac

Natural Connections

Sumac

Emily Stone

Naturalist/Educator at the Cable Natural History Museum

 

As tree leaves stop gathering sunlight for food and prepare for the winter, it seems like that extra light is reflected back to our eyes in the brilliant colors of fall foliage. Green chlorophyll has faded away, and sugars it produced all summer are stored deep within the tree as starch.

 

In some trees, the fading chlorophyll reveals yellow and orange pigments. In other trees, red pigments are created in bright sunlight. While I appreciate the golden light that filters through an aspen stand in fall, it is the red leaves that make me really love autumn.

 

The staghorn sumacs around here are particularly colorful as their leaves morph through a rainbow of color, ending on crimson. They are also fast growing, short-lived, and tolerant of a wide variety of soil types and moisture levels. I am thrilled that sumacs like road ditches, because admiring their lively colors can improve almost any long drive. Sumacs are interesting beyond just their colors, too. Did you know that they are a member of the cashew family? This family also includes mangos, pistachios, and poison ivy!

 

Even while the leaves are still green, sumacs start to show red.  Large conical clusters of red-furred fruits sit at the ends of branches, giving a good show of color from June-September. Not every clump of sumac produces fruits, though. This observation troubled me off and on for years, until I realized two important parts of sumac’s biology: it is dioecious, and it reproduces vegetatively by rhizomes. Let me explain…

Dioecious (which means “two households” in Greek) indicates that each individual plant has reproductive units that are either only male or only female. Most flowers you encounter are monoecious, which means they have male and female parts in the same flower (“one household”). For sumac, this means that some trees are only male, and do not produce fruit. Ah!  That is one part of the equation.

Rhizomes are modified stems that creep underground and send out roots and shoots from their nodes. If you chop a rhizome up, a new plant could grow from each piece. Asparagus is a great example of a plant we propagate by its rhizome. In a clump of sumac, the rhizomes stay connected, and new plants grow outward from the center.  Since the oldest, tallest plants are in the center, clumps of sumac are often attractively dome-shaped.

As the sumac grows new shoots from its rhizome, it is actually producing clones of itself. If the parent plant is male, all the offspring will be male, too, and that clump will not produce fruit. Mystery solved!

To reward yourself for this new knowledge or for a bit of refreshment as you enjoy the fall foliage, why don’t you make a pitcher of sumac lemonade? Gather a half-dozen berry clusters and steep them in a pitcher of cold water for an hour or so. Strain out the seeds, hairs, and bugs through a cheesecloth. Add sugar or maple syrup to taste (remembering that these sweeteners were made by plants using sunlight), then chill and enjoy the rewards of a summer well-lived!

 

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.

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/

 

Sharpies at Hawk Ridge

Natural Connections

Sharpies at Hawk Ridge

Emily Stone

Naturalist/Educator at the Cable Natural History Museum

 

A blustery northwest wind cut right through two layers of wool as I stepped out of the car at Hawk Ridge in Duluth, MN. Binoculars, bird books, hot tea, and windbreakers in hand, my parents and I set up our watch with about fifty other birders and volunteers. Bright sunshine alternated with shadows cast by hurried gray clouds. Up on a wooden platform, several experts peered through spotting scopes, intently searching the sky. Their quarry: hawks.

 

Each fall, about 82,000 raptors pass over Hawk Ridge on their southern migration. Understandably reluctant to cross a large body of water, the birds funnel southwest along the shore of Lake Superior. The high, rocky outcrop of Hawk Ridge Nature Reserve makes a great viewing platform, and people from all over (like my parents from Iowa) come to watch the migration here.

 

Under some conditions, hawks will fly low over the ridge, zooming just above the heads of excited birders. Today, most of the raptors were tiny black specks in the distance, only visible by scanning the wild blue yonder with our binoculars.

 

Raptor biologists here have a special trick for getting close-up views of the hawks – bait. Using a technique a lot like fishing, researchers pull the string on a lure to make it look like an injured bird. When a raptor swoops down for an easy meal, it becomes tangled in one of a series of nets. Researchers carefully extricate it from the net, take a variety of measurements, and attach a numbered band to its leg. About three percent of birds banded here are recaptured. Based on the data collected from recapturing banded birds, sharp-shinned hawks migrating over Hawk Ridge generally head southeast to Illinois, and then southwest toward east Texas and Mexico, following the prevailing wind pattern.

 

Sometimes naturalists bring a recent captive down from the remote banding station so that folks on the overlook can get a better view. Moments after we arrived, two naturalists called everyone over to see a couple “sharpies” in hand. To prevent the hawks from hurting the humans or themselves, the naturalists held their wings, tail, and legs gently but firmly in the fist of one hand. The birds, both hatch-year females, looked quite calm.

 

Sharp-shinned hawks are the smallest hawks in North America, and have the biggest size difference between males and females. Females are up to one-third bigger than males, and this size difference means that they focus on different sizes of prey. Males tend to hunt smaller birds, such as sparrows, while females can concentrate on larger prey, like robins. This has two big advantages: males and females do not compete for the same food source, and chicks can get appropriately sized food as they grow.

 

During the first few weeks after hatching, the female sharp-shin broods the chicks while the male hunts and brings in small songbirds. He typically removes and eats the head before delivering the meal. As the chicks mature, the female joins in the hunting and brings larger prey for the hungry fledglings.

 

Sharp-shinned hawks are agile and acrobatic fliers, navigating dense woods at high speeds by using their long tail as a rudder. Short, rounded wings help them zip through tight spaces after small birds. During migration, they leave the dense forests of their northern nesting grounds and take to the open sky.

 

To help make the journey easier, these and other hawks will ride thermals, which are rising pockets of warmer air, formed by the uneven heating of the surface of the Earth. Thunderheads are visible thermals, where clouds of water droplets show just how high the warm air is climbing. When you see turkey vultures or other birds soaring in lazy circles without flapping, they are riding thermals. The energy in thermals comes from the Sun. You can learn more about them at our current exhibit: STAR POWER: Energy from the Sun.

 

For every mile a bird rises on this avian elevator, it can coast downwind seven miles without flapping. Still, sharp-shinned hawk’ migration from the top of this continent to the bottom takes strength, endurance, and stored energy. In order to be ready for the journey, these small hawks grow furiously—going from egg to adult size in just over 7 weeks.

 

The Hawk Ridge naturalists spent a few minute answering questions, and then asked someone to adopt the birds. For a small donation to support the research, the adopter’s name is linked with the band number of the bird, and if it is ever recaptured, the adopter will be notified. In addition, the adopter gets to release the bird. What a thrill!

 

In a flurry of feathers, the hawk left the adopter’s hand. It swooped below the cliff for a moment, giving us a spectacular “birds-eye view.” With a series of graceful circles, the sharpie gained altitude. Soon the little hawk was a mere speck in the sky, one of the many birds on an incredible journey, visible only through our scanning binoculars.

 

If you would like more information on the migration at Hawk Ridge, visit their website: www.hawkridge.org. You can also join Museum Naturalist, Katie Connolly on a Hawk Ridge field trip on October 18. Call 715-798-3890 for the details and to register.

 

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.

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 Magic of Nature

Gray mist hung in the air over Lake Namakagon, and clouds diffused the early morning sunlight. Fall colors seem deeper and richer in wet weather and half-light like this.  As I turned up County Highway D, I was dismayed to find it turned to gravel, with bright orange Road Work Ahead signs adding their own garish color to the landscape. I admit I was a little irritated that crunchy gravel, washboards, and large machinery would interrupt my early morning scenic drive.

 

At first, I traveled at about my normal speed, since the curves and scenery of this winding road encourage slow driving anyway. Then I reached the flagger, with the STOP sign showing. After a moment of irritation, I noticed a movement out of the corner of my eye. Something small, white, and furry sat quivering in the roadside grass. It scurried a few steps, then froze and looked alert on its haunches. From nose to bushy white tail, the critter was only about 8 inches long – the size of a least chipmunk.

 

Least chipmunks are the smallest and most widely distributed North American chipmunk, focusing their range in the north and west. Their larger cousins, the Eastern chipmunks, range throughout Wisconsin and the Eastern United States. Both are usually light brown, with dark brown and white stripes, live in burrows in a variety of habitats, feed primarily on seeds, and spend the winter underground sleeping and eating occasionally. They do not need special camouflage to blend in with the snow like snowshoe hares, so why was this one white?

 

Two different genetic conditions result in pale animals. The most familiar is albinism. If you have been to the Museum, you probably noticed the albino deer we have on display. In albino animals like this one, two recessive genes combine and result in the loss of the animal’s ability to produce an important brown pigment called melanin. Melanin protects us from UV light, and increases as we get our summer suntan.

 

Without melanin, all parts of the animal are white or pink. The pink color, as in the eyes of a true albino, is a result of blood vessels showing through. Melanin is important for sight and eye development, and albino humans, as well as animals, often have impaired vision.

 

Another genetic condition results in animals with pale fur but normal eyes, or patches of white or pale colors. These critters are leucistic. Birdwatchers regularly report seeing lecuistic robins and other birds with unusual light patches.

 

In contrast, some animals produce far more melanin than usual. These melanistic animals are dark brown or black. Many folks comment on the black squirrel mount in the Museum’s collection. It is simply a melanistic gray squirrel. In contrast to albinism, melanism is often helpful to an animal for camouflage, and in the case of black leopards, it also gives them disease resistance.

 

People often attribute special mystical or spiritual significance to albino animals. In University of Texas tradition, seeing an albino squirrel before an exam confers good luck. In Ojibwe tradition, albino bucks represent the sacredness of all living things, and seeing one should remind us to contemplate our own spirituality.

 

I could not tell for sure which the scurrying chipmunk was – albino or lecuistic –but I knew I had to try to get a photo. I fumbled for my camera, then rolled down the window, turned off the engine, and snapped a few shots. Before long a cool breeze carrying the sweet scent of autumn leaves wafted through the window and past my nose. I took a deep breath and looked out at the sparkling water of Lake Namakagon. With the radio and engine off, my hurried brain quieted, too. This little white critter turned road construction from an inconvenience into moment of peace. Ah, the magic of nature!

 

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.

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/