A Northwoods Almanac for April 14, 2023

 A Northwoods Almanac for April 14-27, 2023   

Sightings: First-of-the-Year (FOY)

            With the return of spring bird migration comes the annual excitement about seeing the first robin, the first sandhill crane, the first common loon, etc. It’s like seeing old friends returning after a long getaway. And if one is lucky enough to have a banded bird return that you know has nested on your property before, that’s an added bonus of truly greeting an individual you know.

            So, here you go (note that my records only show species accounts up to a week before publication when my column is due to the paper):

            3/26: FOY red-winged blackbirds, FOY Canada geese in Manitowish

            3/27: FOY common grackle, FOY northern harrier in Manitowish 

            3/29: FOY dark-eyed juncos in Manitowish

            4/2: FOY sandhill cranes in Manitowish

            4/3: FOY American robin in Manitowish

            4/3: FOY common and hooded mergansers, John Randolph, Minocqua Fish Hatchery

hooded merganser photo by Bev Engstrom

            4/3: FOY merlin, Susan Brandt in Minocqua

Merlin photo  by Susan Brandt

            4/6: FOY yellow-rumped warbler, Bob Kovar in Manitowish Waters

            4/6: FOY song sparrow, fox sparrow, and hooded merganser in Manitowish

            Oh, I should also report that the Manitowish River opened below our house on 3/24. Last year it opened on 4/1, and in 2021, it opened on 3/17, just to show the variability.

            And I should note for the record that the last week of March was superb for crust skiing, which is a relatively infrequent winter occurrence. We have to have a deep snowpack, and then above freezing temperatures during the day, and below freezing at night to create a hard crust. 

 

Land Trusts Presentation

            Are you interested in helping to permanently protect shorelands, woodlands, and other natural resources, now and into the future? Learn how a land trust can be an important tool for conservation in this presentation with three board members from the Northwoods Land Trust (NWLT). The program is on April 17 at 7 p.m. at the Mercer Public Library (715-476-2366), and is free and open to the public. 

            NWLT is a nonprofit conservation organization that has helped protect over 15,000 acres of woodlands, wetlands, and wildlife habitat and 81 miles of water frontage in Iron, Vilas, Oneida, Forest, Florence, Price, and Langlade Counties in northern Wisconsin. Presenters at this program include Ron Eckstein, retired DNR wildlife manager; Cathy Techtmann, Environmental Outreach State Specialist and Professor, Community Resource Development UW Madison-Division of Extension; and me.

            There’s been a lot of misinformation tossed around about land trusts. Come find out the real stories.

 

Birdsong Returning!

            I love this writing from Rainer Maria Rilke in his book The Inner Sky: Poems, Notes, Dreams: “I’ve figured it out, something that was never clear to me before – how all creation transposes itself out of the world deeper and deeper into our inner world, and why birds cast such a spell on this path into us. The bird’s nest is, in effect, an outer womb given by nature; the bird only furnishes it and covers it rather than containing the whole thing inside itself. As a result, birds are the animals whose feelings have a very special, intimate familiarity with the outer world; they know that they share with nature their innermost mystery. That is why the bird sings its songs into the world as though it were singing into its inner self, that’s why we take a birdsong into our own inner selves so easily. It seems to us that we translate it fully, with no remainder, into our feelings; a birdsong can even, for a moment, make the whole world into a sky within us, because we feel that the bird does not distinguish between its heart and the world’s.” 

            I went out this morning, April 5^th, and was greeted by a cascade of birdsong, primarily by the 70+ American goldfinches that have taken up residence. But also by a male cardinal, by a dozen red-winged blackbirds, by another dozen common grackles, by black-capped chickadees, by red-breasted and white-breasted nuthatches, by several pine siskins, by evening grosbeaks by the first robins that have finally arrived, and by an array of other species now all awakening hormonally to spring and all that that means. 

            What a pleasure. What a blessing! Even though it was 35°, and the snow was still ridiculously deep, with more snow forecast for the afternoon, the birds were singing. I wonder sometimes what I will miss most when I finally leave this Earth, and high on the list will be birdsong. 

            It’s not only their musicality, their vitality and vituousity, their joy if you will. I think of the winter wren, a 4-inch-long bundle, whose song has been described as if “he were trying to burst his lungs,” and “as if the very atmosphere became resonant.”  Donald Kroodsma, after effusively praising the winter wren’s voice in his book The Singing Life of Birds, writes, “I experience [its] performance on another level. The wren family originated in the New World, and this wren is the only one that has escaped the New World, now occurring all across Asia and Europe, even into northern Africa . . . Literally, then, the sun always rises on this wren, and his song is heard around the world. I like to imagine waiting in the early morning darkness at Cape Spear, the easternmost point of Newfoundland, where dawn first greets North America each day. There, these wrens are among the first to sing . . . Each wren seems to shout “pass it on,” and, half a second into the infectious charge, the male on the next territory to the west responds, and the next, and the next, each with an intensity as if his own song were to be heard around the world. All along this front, where dawn’s first light sweeps over Newfoundland, “pass it on” radiates from thousands of bills thrown wide, each singer pausing after his first song only after the next hundred wrens to the west have heeded his call.

            “This dawn-and-wren-wave progresses to the west, and I imaging surfing this wave, keeping pace with the light and the song . . . In the span of 24 hours, this wren’s dawn signature sweeps the world. It knows no political boundaries, honors no demilitarized zones, around the globe, dawn is continuously celebrated. My knees are weak, my head dizzy from the intoxicating ride.”

            Yes, birdsong. What a gift.

winter wren

 

Earthworms Are Non-Native Invasives 

            I recently gave a talk on the common trees and shrubs of the Northwoods, and I was surprised to learn how few people know the story of how damaging earthworms are to our northern forests. I’ve written about this issue a number of times before, but because of its importance, the story bears repeating. 

            I realize saying earthworms are evil is deeply counter-intuitive for those of us raised on stories of how good earthworms are for soil, which is true for gardens and farms. However, it’s absolutely not true for forests.

            Earthworms are an invasive species. After the last glacial retreat, no native earthworms lived in the Great Lakes region. But in the last century, we have introduced at least 15 species of worms, spread initially by European settlers, and then hastened along by anglers using the worms as fishing bait. 

            This means that since the glacial retreat over 10,000 years ago, our forests developed in the complete absence of earthworms. Thus, annual leaf decomposition evolved to be controlled by fungi and bacteria, which work so slowly that the accumulation of leaf litter exceeds the rate of decomposition, resulting in the formation of a thick, spongy duff layer on the forest floor. In a rich sugar maple forest, for instance, the duff layer can be up to four inches thick, insulating the ground and keeping it cool and wet in the spring.     

            In response, herbaceous plants like trillium, bloodroot and trout lily have adapted over those thousands of years to germinate and root exclusively in this thick, moist, cool mat. 

            However, as the worm population has grown, the worms have rapidly consumed the duff layer in as little as a year or two, literally eating the duff out from under the seedling plants. By doing so, the worms have altered the physical and chemical properties of the soils, changing the pH, the nutrient and water cycles, and disrupting the symbiotic relationships between soil fungi and tree roots. By the worms removing the protective duff from on top of the soil, they expose the ground to sunlight, allowing the soil to get hotter, dryer, and more compacted, which in turn allows rainwater to run off faster.

            A 2016 study published in the journal “Global Change Biology” involved research by more than two-dozen scientists examining the impacts of worms on forest ecosystems. Scientists from the United States, Canada and the German Centre for Integrative Biodiversity Research at Leipzig University worked on this species diversity project, which joined research from 14 separate studies. They found that as worms eat the leaves on the forest floor, big trees survive, but many young seedlings perish, along with many ferns and wildflowers, all of which changes the composition of trees in a forest. The earthworms amplified the negative effects of droughts, climate warming, and deer grazing on native plants.

            The study also showed that worms helped prepare soils for invading species like buckthorn and garlic mustard which evolved over millennia in Europe right along with the worms.

            Worms also made the soil better-suited for grasses and sedges to move in. Have you noticed woodlands in our area that appear to have what looks like a lawn as an understory? Grasses do better in dry, warm soils – their fine roots can better absorb nutrients and water compared to tree roots. The grasses and sedges are native and common components of forest ecosystem – they aren’t “invasive” species. But they are able to outcompete other native species like large-flowered and nodding trillium, Solomon’s seal, blue cohosh, Canada mayflower, wild ginger, red baneberry, lady fern, bloodroot, bellwort, and the many others that do best in cool, moist soils.

            Add in the effects of browsing by over populations of white-tailed deer, and the vegetative impacts were seen as profound.

            The good news is that earthworms move very slowly, less than a half mile over 200 years. The bad news is that in northern lake districts like ours, lakes are often less than a mile apart, so the worms have eventually spread from the lakeshores and meet in the woodland middle between the lakes. 

            In some parts of southern Minnesota, with better soils, there are now 200,000 nightcrawlers per acre. And that doesn't include angleworms, which can be as thick as 400,000 per acre – all of them digesting plant material and leaving the forest floor more bare. Minnesota is probably 90 to 95 percent infested with foreign worms, the researchers say.

            Bottom line? “The earthworm invasion has altered the biodiversity, and possibly the functioning of the forest ecosystems, because it affects the entire food web as well as water and nutrient cycles,” said Dylan Craven of Leipzig University in Germany, lead author of the study. Added Lee Frelich from the University of Minnesota’s Center for Forest Ecology, “When you change the structure of the soil, which everything else is based on, the ecological cascades are going to ripple through the entire ecosystem.’’ 

            So, what can you do? Well, very little about the existing earthworms now in our forests. But if you fish and ordinarily dump your leftover worms in the woods, cease and desist. And if you have a compost pile or garden full of worms next to the woods, please bury a metal barrier around the garden to prevent the earthworms’ dispersal.