Friday, November 25, 2016

Not Mosquitoes!

One evening a few weeks ago, I looked up from my computer to see a thick swarm of mosquitoes at my window. Hundreds, maybe thousands, of the tiny, leggy, little buggers bounced against the screen in the lamplight. More swarms greeted me in the morning, as they knocked against the windows and formed a gauntlet to my car. Several carpooled to work with me. Others joined me while brushing me teeth the next evening.

The bugs were everywhere. But none had landed on me, or tried to bite, or even buzzed in my ear. That’s not typical mosquito behavior! So, in the spirit of science, I caught one out of midair and gently squashed it. Even a hand lens couldn’t tell me much about this tiny tangle of legs, but after a photo shoot with my macro setting, I was able to ascertain this critter’s innocence: it was definitely not a mosquito.



The spines on its knees were my first clue. The lower joint of each leg had at least one and sometimes multiple little pointy prongs sticking out of it. The two tiny wings were clear and delicately veined. The abdomen was narrow and dark, with a lighter tip. And, most oddly, a projection on the underside of its thorax, what we’d think of as our chest, almost looked like a pale-colored mite clinging like a monkey on his mom.

Stumped, I sent my photo around—first to one entomologist friend, then another. When between the two of them I came up with the family Mycetophilidae and the common name “fungus gnat,” I sent the photo to “my mushroom guy” and he confirmed “Definitely Mycetophilidae. Huge family over a thousand spp. Google glow worms…”

Mycetophilids are in the order Diptera with mosquitoes, gnats, and other two-winged flies.  As I parsed the Wikipedia article, everything began to make sense. They are described as having a “strongly humped thorax and well-developed coxae.” Did you know that an insect’s coxa is the base of its leg, roughly equivalent to our upper thigh? Neither did I. But the humped back and large, pale-colored coxae on my insect are what had looked like a monkey-baby mite to my unaided eye. Fungus gnats are also said to have spinose legs, which must be the scientific way to describe bayonets sticking out of your knees.

I was a little disappointed that none of my entomologist friends could identify my little guy to species. As it turns out, this would require close study of wing venation (ok, that’s not too hard) and chaetotaxy (which means the arrangement of the bristles on their body), and genitalia (which strikes me as a little too invasive for such a recent acquaintance.) Plus, with over 3,000 species in Mycetophilidae, it might take weeks to get through a dichotomous key.

“Most of their natural history secrets remain untold.” wrote Peter H. Kerr in his entry on fungus gnats for the Springer.com Encyclopedia of Entomology. That may be so, but we know more than nothing. For instance, fungus gnats occur on all continents except Antarctica. Most (but not all) types of fungus gnats feast on the fruiting bodies, mycelia, and spores of fungi. They prefer damp habitats where their favorite fungi grow, and sometimes form thick swarms. In those forests, they play an important role in the food web.

A few species of fungus gnats become pests in the damp soil of gardens, farms, nurseries, and overwatered flower pots. Most of the time, though, a female fly will lay her eggs—up to 1,000 in her week-long life—in the cap of a freshly sprouted mushroom. The larvae develop quickly (three weeks from egg to adult) while burrowing into the cap, or make sticky webs on its underside. A few types of larvae are semi-predacious and may eat other insects who visit the mushroom.

Later, I took my mushroom guy’s advice about Googling “glow worms.” Radiant turquoise jewels dripping from cave ceilings appeared in Google Images. As it turns out, in a related family of fungus gnats, about a dozen species have developed bioluminescence. They mostly live in sheltered grottos in New Zealand and Australia. There, tiny larvae spin nests out of silk on the ceiling and dangle dozens of threads of silk beaded with droplets of mucus. Breathless, calm habitats are necessary so that their lines don’t get tangled. Breathless, I’m sure, are explorers who find a replica night sky illuminated on the ceiling of a cave.

The gnat larvae’s glow results from luciferin, a chemical compound similar to that used by fireflies. A hungry larva glows brighter than one who has just eaten, and that glow lures midges, mayflies, mosquitoes, and moths to their doom.

A trip to New Zealand may be in order someday, but for now, I’m just happy to know that it wasn’t a pack of mosquitoes still trying to invade my house in November!

Special Note: Emily’s book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses is here! Order your copy at http://cablemuseum.org/natural-connections-book/.

For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new phenology exhibit: “Nature’s Calendar: Signs of the Seasons” is now open.

Friday, November 11, 2016

Driving Back in Time

Everything along the highway south of Duluth was a dismal November gray when I started out on a road trip to visit my favorite cousins; out of touch since the last family wedding two years ago. The skeletons of trees, the low, damp clouds, even the road itself conspired to be gray. A few patches of oaks held their coppery leaves, but they were subdued without the sun. As I sped south, though, I felt like time was moving backward. The fall phenology of color change and leaf-off that I’ve been observing at home unfolded in reverse beside my humming wheels.

First, golden triangles jumped back onto the twigs of a few aspens and clung there fluttering the breeze. Next, I started noticing some of the planted trees and shrubs—weeping willows in yards and something burgundy in the fence lines—still dressed in color.

By the time I got to the city of St. Paul, I’d traveled back a few weeks at least, to the time when sumacs blazed not just with red, but with the full rainbow of green, yellow, and orange as well. When did the sumacs turn in Northern Wisconsin? Early October was my best guess, 3 to 4 weeks ago. In town, other trees held their leaves, too. Brown skeletons were still evident in the post-Halloween landscape, too, but they didn’t dominate like up north.

Emerging on the south side of The Cities, I found myself back in a skeleton land. The city must be a little heat island, tricking plants into a longer growing season. The introduced species, especially, tend to stay green longer. Buckthorn, for example, doesn’t even really have fall colors. Its leaves just go from green to dead. I also suspect that even the native species of planted city trees don’t have quite the same genetics as their wild cousins. The timing of fall leaf drop is affected by both nature and nurture; their genes and their local environment.

By the time I’d reached my first destination in Ames, IA, the changes were drastic. Some trees, especially the ashes, were bare. Ashes don’t have any tolerance for cold. Their strategy is to leaf out late in the spring after all chance of frost is gone, and then drop those leaves early in the fall. But the backyard of my family friends sported a highbush cranberry with fully emerald foliage and clusters of scarlet berries. The big, old oaks in their neighborhood had dropped just a fraction of their canopies. And a katydid sang as we chewed the fat. Many other trees that could never grow up north (i.e. redbud and sycamore) also held their foliage. I have nothing to compare with their timing. We walked around a nearby park, and I shed my sweatshirt in favor of a tank top.  Just 300 miles south, and it felt like I was back in early October.



When I headed south again the next day, the sweatshirt never went on. With an hour to kill, I took an early morning walk in a nearby woodland. Chickadees gave their gargle calls in an effort to sort out the dominance hierarchy in their winter flocks (that, at least, was the same). Then a bright flash of color caught my eye. A huge patch of yellow-orange chicken of the woods mushrooms glowed along a fallen log. They were fresh and juicy, still young, and not riddled with beetles. Those same mushrooms peaked just before Labor Day in my woods. Here in central Iowa, their season must be extended by at least two months!



So few trees lined my view on the way through Kansas that I could hardly judge their progress into autumn. Arriving in the town of Atchison, though, (having driven across four of the USDA’s plant hardiness zones) I found maples in full color, other trees still green, mums and impatiens blooming in my cousin’s flower bed, tomatoes still ripening on her vines, and a yellow butterfly dancing around the park. The 79 degree day just about melted me. Not all trees are benefitting from the warm weather, though. A few ashes and maples have lost their leaves in solidarity with their northern cousins.

The chilly mornings and warm sunshine here in Kansas remind me of early September in Northern Wisconsin. They are having a heat wave, the locals tell me, but even so the average temperatures for early November are 15 degrees warmer in Kansas than in Hayward.

A recent article in the New York Times highlighted new research showing that fall color displays may actually lengthen for a while—as warm weather lasts longer into the year—before they eventually collapse with the loss of our most colorful species when they are forced farther north by the changing climate.

Happily, my visit felt like driving back in time in more ways than one. My cousin hasn’t changed a bit…except that the little girl with light brown curls is her daughter instead of her little sister (boy do they look alike!). Our conversations, too, were as easy, winding and distracted as ever, jumping from one thought to the next. There are some things that neither distance nor climate can change.

Special Note: Emily’s book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses is here! Order your copy at http://cablemuseum.org/natural-connections-book/.


For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new phenology exhibit: “Nature’s Calendar: Signs of the Seasons” is now open.

Friday, November 4, 2016

Mount Telemark

Piling out of our cars onto the cracked concrete parking area, we all commented on the perfect weather for our hike. Sunshine, a light breeze, and 45 degrees is about as good as it gets in late October up here. This group of curious adults was gathering for a walk titled “Why Wisconsin Forests Look the Way they Do #5,” led by John Kotar, emeritus professor of forest ecology from University of Wisconsin-Madison, who literally wrote the book on natural communities in the Great Lakes region.



Our destination was Mount Telemark—a place with a lot of history. As we hiked up the gravel access road, weathered sheds huddled in the bushes and rusty ski lifts peeked through the trees and overgrown fields. Telemark Lodge was an alpine ski area founded by Tony Wise in 1947, one of the first in the United States. Tony had discovered alpine skiing while stationed in the Bavarian Alps during World War II, and then used a GI Loan to purchase this hill. The resort eventually became a hub of cross-country skiing, and the birthplace of the world-renowned American Birkebeiner ski race. The impressive lodge with its giant fireplace was built in 1972; a Colosseum with four tennis courts added in 1980; and in 1984 it went through the first bankruptcy (of four).

I personally have relatively few memories of Telemark Lodge when it was open, but in the collective memory of our community, our region, and skiers across the country, this place looms large.



At the center of it all is Mount Telemark, a 300-foot-tall “mountain.” Topo maps show a wide, irregular hill; elongated NW to SE and rising above a sea of lumpy terrain. Legend says that the Ojibwe named it Kawabming, meaning “place to look out from.” The view is quite nice. It attracted skiers here in the 1980’s, and it drew us here today. John Kotar himself has a long history of Birkie skiing and Telemark memories. But its history began long before the Ojibwe, Tony Wise, or John Kotar arrived.



Around 10,000 to 14,000 years ago, near the end of the last ice age, this area was buried under a mile or more of glacial ice, and the ice was melting. The retreat of the glacier was a messy affair. Glaciers don’t glide backward, they disintegrate. Chunks of dirty ice broke off and got buried or surrounded by heaps of debris. Sand and gravel filled in every possible hole, crack, and gap in the remaining ice.

Sediment-choked rivers of meltwater coursed along the glacier’s surface and plunged downward through crevasses, or vertical shafts called moulins. By one account, Mount Telemark was created in one of these moulins. First, sediment would have piled up in the hole, and then become a hill when the ice melted away. By Kotar’s account, the sediment may not have filled in such an orderly space, but simply a gap in the ice that was created as the glacier parted around a bedrock lump. In either case, we ended up with a giant hill of glacial remains. In fact, this is the tallest pile of glacial sediment (technically known as a kame) in all of Minnesota and Wisconsin.

The steep-sided landform provided slopes for 10 different ski runs in its heyday—served by six ropes, 3 T-bars, and 3 double chair lifts. In a little twist of irony—on top of a hill once buried by a mile of ice—Tony Wise devised some of the original snowmaking equipment in the Midwest. The first iteration involved using logging sleds to haul snow up from the airport runways and blowing it out over the slopes with a silo loader. The very next year they installed a commercial system that used Larchmont Snow Guns and pipes—still visible along the forest edges—to carry water uphill.



This landform, made of gravel and cobbles, also provides dry, nutrient-poor soil that favors trees like oaks, pines, and birches. The human disturbance of cleared, then abandoned, ski runs also has impacted what grows here. The gently sloping clearing that we hiked up, for instance, sported a thicket of slender birch trees next to the rusted cables of a ski lift. Birches have very low shade tolerance, and took advantage of the sunny, open space to get a head start.

The view from the top was spectacular. Two vibrant, orange maple trees stood out in the sea of evergreen, rich oak-brown, and tamarack gold. We also could see an airport, golf course, roads, distant fire tower, and more remnants of the resort buildings and ski runs. Of the five places we’ve visited with John to learn “Why Wisconsin Forests Look the Way they Do,” this one especially drives home the fact that glaciers and humans have been two of the driving forces shaping nature in the Northwoods.




Special Note: Emily’s book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses is here! Order your copy at http://cablemuseum.org/natural-connections-book/.

For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new phenology exhibit: “Nature’s Calendar: Signs of the Seasons” is now open.