Murmuring Trees

“Trees, trees, murmuring trees!” Through closed windows on a chilly morning I hear the welcome song of an old friend. It is followed by an emphatic chant from deeper in the forest. “Teacher. Teacher! TEACHER. TEACHER!” And then a buzzy, upward-trending “Parrrrrrrrula.” I catch a flash of movement out of the corner of my eye, and then hear the squeaky "wee-see-wee-see-wee-see" of yet another neighbor.

The warblers are back! Warblers are a group of active little birds that are often colorful, insectivorous, and (as their name suggests) vocal. They spend the winter in exotic locales to the south, and travel thousands of miles on their tiny wings just to raise their young in the Northwoods. You may be wondering what attracts them all the way up here from sunny Mexico and Costa Rica. Are you reading this on your deck? Then the answer may be sucking your blood or buzzing in your ear at this very moment.

Blackflies. Mosquitoes. The warblers come here for the feast. Moths, wasps, bees, caterpillars, larvae of all kinds, leaf beetles, bark beetles, weevils, ants, aphids (and their honeydew), caddisflies, craneflies, mayflies, stoneflies, dragonflies, grasshoppers, locusts, and gnats. During outbreaks of pests like the spruce budworm, warblers become rainbow-colored exterminators.

Could we please have a resounding “Thank You!” for the warblers?  Let us put them on a pedestal with spiders and bats and thank them all for eating insects.

Not only do warblers eat insects, but they look and sound delightful while doing it. For those of you who are curious, the bird songs mentioned at the beginning belong to, in order, Black-throated Green Warblers, Ovenbirds, Northern Parulas, and Black-and-white Warblers.

If you would like to learn more, there are plenty of opportunities every spring at the Chequamegon Bay Birding and Nature Festival. There are over 100 activities and field trips planned for birders and nature lovers of all skills and ages. Check out the field trips and register at http://www.birdandnaturefest.com/.

Slugs

Have you ever really looked at a slug? Not many people have, I would guess, except for gardeners who pluck them off ripe tomatoes. I first began to appreciate them after watching a French documentary called Microcosmos. It is a stunning film that captures a day in the life of a meadow – from a bug’s eye view. The crowning scene, for me, is a romantic encounter between two snails. Their antennae touch tentatively, then caress enthusiastically. It is all undulating, glistening slime on a bed of vibrant moss as they slowly topple over in ecstasy. Whew! A bit steamy, even for invertebrates. Snails, of course, are relatives of slugs. Slugs are basically snails that have adapted to living in areas without much calcium from which to make a shell.

Just the other morning I found some slugs on my driveway doing very important work. There were about ten of them, each bright gold body just over an inch long. They were gliding hungrily over a giant pile of bear scat. Slugs are decomposers – unsung heroes of nature. Unless you are an avid gardener with an active compost pile, you probably do not think about decomposers often. They work in the dark, dank depths of the world, neatly breaking down organic material into the ingredients for new life. Each beautiful wildflower, every fresh tomato, is made possible by behind-the-scenes decomposers.

At science camp, we called this team the “F.F.B.I.,” which stands for fire, fungus, bacteria, and invertebrates.

Some plants have very specific partners – like the trailing arbutus I mentioned last week, with its mycorrhizal relationship with fungus on its roots. Jack pine is a classic example of a plant that likes to collaborate with fire, since the resinous cones and tiny seeds of the tree need heat to open, bare soil to germinate, and a ready supply of nutrients from the ash. Ants are an invaluable invertebrate both to peonies, who need ants to chew open their buds, and to trilliums, who need ants to plant their seeds.

Human tinkering can disrupt these partnerships. Earthworms can increase nitrogen in the soil, but while that is good for your tomatoes, it can be bad for native plants. Earthworms are not native in lands like Northern Wisconsin, where glaciers still froze the ground solid just 10,000 years ago. Escapees from gardens and bait buckets invade forests. Maple seedlings and wildflowers actually need the fallen leaves for seed germination, and these European earthworms are too efficient at their vocation of decomposing the leaves.

The connectedness of nature became apparent when researchers discovered that earthworms are to blame for the population decline in ovenbirds, a ground-nesting warbler. Less leaf-litter means fewer insects for the ovenbirds to eat. Taller flowers and ferns that thrive in thick leaf litter are thinning out and being replaced by grasses and sedges that do not provide good nesting cover.

Like all things in nature, balance is necessary for a health. Worms are helpful in some ecosystems, but worms in the wrong place upset the balance. Too much fire will sterilize the soil; too many insects may decimate a tree. Wintergreen in the road ditch has beneficial fungus on its roots, and a powdery white pathogenic fungus on its leaves. Consider our own bodies where there are multitudes of helpful bacteria and a few that can cause serious harm. In trying to manage the harmful ones, we do not want to eliminate everything.

So as you admire the conspicuous beauty this spring, remember to appreciate the web of support that keeps it going. We all need “decomposers” in our lives – those partners who help us to nourish our souls, break down barriers, clean away debris, turn failure into beauty, and cycle with joy through many seasons of growth and renewal.

Think about that the next time you see a slug!

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, opens in May 2012. Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com/

Conspicuous Beauty

“Conspicuous beauty” surrounds us in this stage of spring. A soft green haze covers the tamarack swamps as their delicate needles emerge. The cries of loons finding mates and defending territories echo over glassy lakes. More subtle songs fill the forest every day as warblers migrate through or set up territories. New flowers peek out from every habitat and patch of sun.

Two of the wildflowers blooming now hold special places in my heart, with two very different styles. The white clouds of blossoms on serviceberry shrubs are the most spectacular. This member of the Rose family blooms synchronously, with 90% of the flowers of a tree opening within two to five days. As legend tells, this lovely bush earned its name because it blooms when the ground has thawed enough so funeral services can be held for unfortunate souls who died over the winter when the ground was too hard to dig.

The synchronous bloom also creates a bonanza for the small bees that pollinate it. Even though the nights are still chilly, bees can shiver to warm up their flight muscles, and their fuzzy coat helps to insulate them against frosty temperatures.

I first discovered serviceberry in a botany class. We only learned to identify it to genus – Amelanchier – because the species are notoriously hard to tell apart.  Of the twenty species in the genus, nine of them live in Wisconsin! I never learned it as a kid, because I grew up in the limestone bluffs of the Driftless Area, and serviceberry is not tolerant of calcium carbonate. It prefers higher acid soils like the sandy glacial outwash and igneous bedrock of this region.

Trailing arbutus, another favorite flower of mine, also likes acid soils and has white, five-petaled flowers. Its scientific name, Epigaea repens, which means “trailing upon the Earth” describes its growth habit perfectly. Although the trumpet-shaped flowers look and smell wonderful, it can be hard to find them among the thick mat of broad, oval, leathery evergreen leaves. Without a trained eye, it may be mistaken for wintergreen, a close cousin.

I first discovered trailing arbutus on a portage trail in the Boundary Waters during an early spring canoe trip. It cheered me up immensely after a few days of traveling in wet snow and high winds.  I am not the first to appreciate its early spring beauty – as legend tells, it was the first flower to cheer the hearts of the Pilgrim Fathers after the rigors of their first New England winter. This earned it the alternate common name of Plymouth Mayflower, and the honor of being the Massachusetts State Flower. One author described it as having “the fatal gift of conspicuous beauty” that led to it being dug up and sold in eastern cities in the 1900s.

While many people love it, and have tried to transplant it into gardens, trailing arbutus does not fare well with disturbance.  Like orchids and blueberries, trailing arbutus has a mycorrhizal relationship with fungus on its roots. The plant has almost no root-hairs, which in other species are key for increasing the surface area available to absorb water and nutrients from the soil. Fungal hyphae (fine root-like parts of a fungus) surround and penetrate root cells, which allows for an exchange of water and nutrients from the fungus, and sugars from photosynthesis in the plant. A study in the Harvard Research Forest found that 91% of plant species there had similar fungal friendships!

Spring is a wonderful time to enjoy both the conspicuous and the inconspicuous beauty of nature’s awakening.

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, opens in May 2012. Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com/