November 6, 2021 by Beth

Autumn Nostalgia

It rained leaves yesterday: red and silver maple, elm and basswood. Ash and birch fell last week. Other maples, oak, aspen, hackberry and ginkgo are still to come. The sky was hazy sun, the air windy and mild. A few late asters bloomed and honey bees jostled each other seeking the season’s last pollen and nectar. I am nostalgic for another summer gone by and I do not look forward to winter.

The leaves kindle warm memories of the past: Nighttime walks scuffling through dried leaves with family and friends; autumn bonfires, years of after-school leaf walks with our young son. His warm, small hand held mine and his other was packed with leaves for projects — leaf bouquets, nature collages and little booklets with leaves and seeds of neighborhood trees.

I miss the leaves; every year it’s the same. I miss their spicy scent, earthy and tangy with just a touch of sweetness as they break down. I miss their nighttime whispers on warm, summer winds, and the rattle of older, dry leaves in autumn. November winds whip them into swirling, airborne eddies and send them skittering down streets. They catch among rocks and old stalks, tucking in our garden until spring. Summer’s green umbrella slowly smolders to yellow, orange, russet, red and maroon. The canopy thins and falls, nestling woodlands and yards under a colorful quilt for winter.

October 14, 2021 by Beth

Wooly Bear Caterpillars

I found this little wooly bear asleep in the garden under a pile of fallen leaves and tucked it back in for the winter.

I miss the hum and activity of bees, butterflies and other insects that populate our garden. But, as I finished up some outdoor work, I was reminded that their absence is temporary. I spotted a familiar small, fuzzy form: a banded wooly bear caterpillar (Pyrrharctia isabella) asleep for the winter beneath some fallen leaves.

Though we usually call these little creatures wooly bears or wooly worms, there are more than 260 different species of them in North America. Each has a different coloration and becomes a distinct species of moth. The banded wooly bear is black on both ends with rusty orange in the middle. When the caterpillar reaches maturity, it becomes an Isabella tiger moth. Though I’ve seen many banded wooly bears, I have yet to see the moth, which is usually a muted orange, salmon or yellow color with black spots on its body and wings.

Wooly bears are generalists — they eat many types of plants including grass, clover and weeds. This one had just crossed the Lake Nokomis walking path in Minneapolis.

The banded wooly bear caterpillar grows up to 2 inches in length. Its fuzzy body is covered in tiny bristles called setae that are black on the caterpillar’s ends and rusty orange in the middle. The number of orange segments increases as the caterpillar grows. Though a few people might be sensitive to the bristles, most have no problems handling the caterpillars. I remember carrying them around as a child and holding them with our toddler son on nature walks.

Is it true that the size of a wooly bear’s orange band predicts the quality of the winter ahead? No, according to the sources that I read (please see the list below). Explanations include: the size of the orange band increases as the caterpillar grows; those with more orange grew up in a drier habitat and those with more black segments grew up where it was moister; lots of variety occurs naturally among caterpillar populations; and there’s plenty of disagreement among all of these views. In spite of the arguments, it’s fun to observe, compare and chart the size of wooly bears bands — especially with children!

Banded wooly bears in Canada and the northern United States typically produce one brood each year, though two generations are possible. Those that hatch in August feed until late autumn. They eat a broad range of grass, weeds and wildflowers, and aren’t crop pests. In autumn, they enter quiescence (a type of insect dormancy) for the winter, usually in leaf litter, or under a log or rock.

Look for wooly bears on sunny, mild autumn days. This one crossed the Sakatah Singing Hills Trail in southern Minnesota.

How do they survive our harsh winter? They produce a cryoprotectant,¹ an antifreeze to prevent cells from rupturing when they repeatedly freeze and thaw. The bristles or setae also help the caterpillar to freeze on the outside first, protecting the inner organs. In the spring, each caterpillar will awaken from quiescence, resume feeding and spin its cocoon. About two weeks later, an adult Isabella tiger moth will emerge.

Banded wooly bears range throughout the United States, Canada and even into Mexico. You might catch a glimpse of them feeding in the spring, but it’s more likely that you’ll spot one in autumn when you’re out walking, biking, or working in your garden.

wooly-bear-caterpillar-tom-2

Sources List for Further Reading

The Infinite Spider Blog

Minnesota Department of Natural Resources

NPR Science Friday video

National Weather Service

Scientific American Blog

University of Wisconsin – Milwaukee: Bug of the Week Blog

^¹The cryoprotectant is produced by other wooly bear species, too. In fact, the Arctic wooly bear (Gynaephora groenlandica) caterpillar has a life cycle that stretches over seven or more years! The Arctic summers are so brief that the caterpillars must feed and enter quiescence repeatedly for several years before gaining enough biomass to metamorphose into a moth. Overall, they spend 90 percent of their lives dormant and frozen! (For more about the Arctic wooly bear, follow the link above to the Scientific American Blog.)

September 13, 2021 by Beth

Gray Tree Frogs

Like tiny amphibious chameleons, gray tree frogs (Hyla versicolor) change color to match their surroundings. Sometimes bark-like gray or brown, at times a leafy green, and at others a mottled combination of color that mimics lichens or rocks, these tiny frogs elude predators through camouflage. Sometimes they even display a shade of creamy white or tan. No matter what color they exhibit, all gray tree frogs have bright yellow or orange marks under their thighs.

Why are they “tree” frogs rather than just frogs? All species known as tree frogs (or treefrogs) have large toe pads that enable them to climb trees, sides of buildings, and other structures. Climbing trees is all about catching the wide variety of food available there on warm summer nights: small insects and their larvae, spiders, mites, aphids, snails and even smaller frogs. At night gray tree frogs also climb sides of houses to perch on windows and capture small moths and other insects attracted to light. Because gray tree frogs are nocturnal, I often hear rather than see them unless they perch on the windows. What preys on them? Small mammals such as skunks, raccoons and opossums. Snakes, birds and larger frogs also eat them.

*Artificial lights attract gray tree frogs in search of insects. This little one climbed* *the side of the house.*

Gray tree frogs typically inhabit woodland edges and gardens near water. We’ve seen them at our cabin in rural Minnesota, and my sister, who lives in a Twin Cities suburb, has regulars that hang out in her garden. They pop up in damp places — the cat’s water dish, inside her garden watering can, under flower pots, on the patio furniture and in her small fountain. Adults are typically found higher up in trees or shrubs, while younger tree frogs are more terrestrial.

*This tree frog’s golden color blends well with the potted plant.*

*Gray and charcoal hues help camouflage a tree frog on this weathered deck.*

Unlike most frogs, the gray tree frog sounds more like a bird as it trills its one-note call. They breed from April to July and call most frequently during May and June, though it can be as early as April and as late as September. Females lay their eggs near a shallow pond or pool of water. Hatching and development takes about 7-8 weeks. They reach adulthood in two years and the average life span ranges from 5 to 7 years. Adult size is generally 1-to-2 inches (3-to-5 cm) in length.

Tree frogs hibernate on land, usually buried under leaf litter, fallen logs and other materials. Their bodies produce glycerol, which is converted to glucose. Large amounts of glucose in the frog’s vital organs acts as an antifreeze. Ice crystals will form in the body cavity and under the skin, but the lungs and heart are protected from freezing, and stop functioning until spring. Warm weather will thaw the frog and it will revive and continue its life. Gray tree frogs live in eastern North America from New Brunswick to Manitoba, south to northern Florida and west to central Texas.

*Young gray tree frogs are often bright green.*

Robins and Apple Blossoms

Robins and apple blossoms will always symbolize spring to me.

Spotting a robin in March signaled the onset of spring to me as a child. We had a “Golden Book” titled, Birds: A Child’s First Book About Our Most Familiar Birds. It featured drawings of neatly woven nests cradling delicate eggs and portraits of familiar garden birds. Illustrations often showed robin nests built in blossoming apple trees and that image, along with the robin’s melodic songs, became synonymous with spring in my young mind.

Rose-colored beacon apple buds open to white blossoms.

Decades later, my husband and I bought our home in Saint Paul. Our first evening there, we sat on the back stoop beneath a beacon apple tree that’s now more than 80 years old. Two adult robins flew in and out of its leafy crown indicating the presence of a nest. A chorus of high-pitched chirps greeted the parents as the hatchlings anticipated dinner, their tiny heads stretching over the nest’s rim. During the next few weeks, we were privy to nestling squabbles, flight training, food procuring and the proper way to down a worm!

An American robin (Turdis migratorius) hunts worms and grubs for hungry nestlings.

Some say that red-winged blackbirds (Agelaius phoeniceus) are the new sign of spring’s return to Minnesota. Robins now winter in the state and I hear their sweet songs on milder midwinter days. Many birds can withstand very cold weather as long as they find enough food to fuel their metabolic rate. Gardens often feature crabapple, mountain ash, dogwood and other fruit eaten by wintering birds. City boulevard plantings include fruit trees and larger trees like hackberry. I frequently see large groups of wintering robins dart between the crowns of boulevard hackberries near Saint Catherine University in Saint Paul. Robins also eat bird feeder food during winter that they wouldn’t touch in other seasons. Many a robin has dined with the woodpeckers at our suet feeder!

Sometimes I wake up to robin song drifting in through my bedroom windows in the predawn darkness. I remember childhood mornings of their pure, lovely caroling along with the scent of lilacs, the touch of humid air and perhaps thunder rumbling in the distance from an early morning storm. These are joyful memories — and though robins often ride out the winter in Minnesota, their clear singing, and the beauty of apple blossoms, still signify spring to me.

Our beacon apple tree (Malus domestica ‘Beacon’) is more than 80 years old. Standing beneath it, I hear the steady hum of bees pollinating the delicate blossoms.

Early Spring Native Flowers: Bloodroot

Native bloodroot flowers (Sanguinea canadensis) emerge with a single leaf tightly wrapped around each of them. (Notice the early native bee near the top of the photo!)

One of Minnesota’s earliest native wildflowers is bloodroot, (Sanguinea canadensis). Given its name, you might expect a scarlet or crimson flower. In fact, it blooms ice-white with a sun-gold center, though some emerge light pink. They look out of place, so stark and fresh among the remains of last year’s woodland growth and garden detritus. Its name refers to the toxic red-orange sap in the rhizome or root.

Each bloom emerges wrapped in a single curling leaf like a little blanket. The leaf remains curled until the blossom withers and then unfurls into a rounded leaf with a varying number of lobes. The leaves range in color from light green to blue-green depending on the plant’s age and condition. In its natural setting, bloodroot often grows along woodland edges, which provide sun in early spring and shade when the trees leaf out. In my garden, it grows along the edge of an arbor vitae hedge and under an ash tree. With shade and regular watering, bloodroot creates a pretty ground cover that lasts all summer under deciduous trees. If they aren’t watered during summer’s hot, dry spells, bloodroot leaves just go dormant until the following spring.

Sometimes the flowers have a pink coloration when they open.

Native bees, honey bees and beetles pollinate bloodroot, which also can self-pollinate. Fertilized flowers form elongated capsules that enclose spherical seeds colored black, red, or brown. Here’s what’s special about bloodroot seeds: Each produces an elaiosome, an attachment containing lipids, amino acids and other nutrients. Attracted to these nutrients, ants carry the seeds back to their nests and feed the elaiosomes to their larvae. The ants either discard the remaining seed in a separate chamber of their nest, or toss it back out onto the ground. Either way, this process, called myrmecochory, helps ensure that the bloodroot seeds are dispersed for germination. Other spring wildflowers, such as violets, trilliums, hepaticas and Canada wild ginger, also form this mutual relationship with ants.

Ants help disperse the seeds after ripe bloodroot pods split open.

A member of the poppy family, bloodroot is native to much of eastern North America from Nova Scotia south to Florida, west to Manitoba and south to Texas. Native Americans used the plant’s red sap to make paint and to dye clothing, leather and other items. It blooms from March to May in Minnesota woodlands and was one of the first native wildflowers that I identified in the woods at our cabin years ago. The plants in most of these photos grow in our backyard. They hold special meaning for me because they were a gift from my aunt, who grew them under her trees for decades. They remind me of how she nurtured my love for nature when I was young.

Native bloodroot covers a hillside above the Mississippi River in the Twin Cities.

Spring Happens All Around Us

Raindrops collect on new spirea (Spirea japonica) leaf rosettes.

On a recent morning, a friend looked outside and noticed the green blush beginning on trees and bushes. She recalled a teaching colleague’s comment during playground duty years ago. The colleague, a quiet woman of few words said, joyfully, “Oh, take a look! Spring is happening right before our eyes!”

Indeed it is. Thunderstorms, rain and mild temperatures coaxed baby leaves from their snug buds. They open like tiny green roses, flawless and smooth, not yet chewed upon by insects or mammals. Even on these cloudy, gray days buds and baby leaves paint the landscape in soft pastel greens and yellows. Don’t miss their fleeting, fragile beauty! They’ll quickly mature to full size and summer’s cool greens.

Many baby leaves, like these oaks, emerge in shades of yellow or “spring green” and later deepen to their full color.

New leaves open like flawless green roses on dwarf Tina Sargent crabapple (Malus sargentii ‘Tina’)

March 31, 2021 by Beth

Maple Flowers

In Minnesota, native maple trees typically flower before bees and other pollinators are active.

Spring’s earliest flowers are popping open: gauzy crocus clusters, squill — Siberian and striped — and snowdrops that have bloomed through snow, cold and high winds for a month. They are lovely, these Eurasian transplants that paint the earth with pockets of bright color. Our native blooms are more hidden and less showy, yet are beautiful in their unflowerlike forms.

Look up at the maple trees. Easy to miss high overhead, these blossoms are small, muted and less recognizable as flowers. Each emerges from a scarlet bud coat and glitters with golden, translucent filaments tipped in auburn pollen. They remind me of minute, single-celled creatures that we might see in a drop of water under a microscope, or of the tiny squiggly animals living on a coral reef — beauty suspended in air rather than water.

Male flowers of the silver maple (Acer saccharinum) are packed with pollen for wind dispersal.

The female flowers of red maples (Acer rubrum) remind me of tiny coral reef creatures.

Oh, and even if we don’t notice the flowers overhead, if you are allergic to tree pollen, your “nose knows” that maples are blooming! Why do they disperse so much pollen? In most years, maples and a few other trees bloom before native bees and honey bees are active. The early-flowering trees depend on indirect wind pollination. Male flowers produce copious pollen to successfully fertilize female flowers on other maples.

February 13, 2021 by Beth

Who Will Nest Here?

Black-capped chickadees, downy woodpeckers and white-breasted nuthatches recently explored this cavity in our apple tree.

Our beacon apple tree is pushing 80 years old. It’s dropped a few limbs over time; some splintered under the weight of apples, others weakened with age and rot. One old limb bears a small cavity. “So what?” you think — unless you’re a chickadee, nuthatch or other cavity dweller looking for a nesting site. All three species frequently explore and tussle over this cavity, and I believe the chickadees are winning.

One sunny, frigid afternoon, a downy woodpecker pair ducked in and out of the cavity and were confronted and chased away by a black-capped chickadee. A curious white-breasted nuthatch also sidled over for a peek and was waved off by the chickadee. Later, three chickadees fluttered around the opening until two chased off the third. The remaining pair excavated and removed wood chips from the cavity interior; evidence they are preparing a nesting site! The male sings his territorial “fee-bee” (sometimes “fee-bee-bee”) song. I first heard him sing on December 31.

One member of the black-capped chickadee pair (Poecile atricapillus) removes wood chips from the apple tree cavity.

Chickadees deposit excavated wood chips away from the nest site to avoid leaving signs for predators.

Will this pair nest in our apple tree? Black-capped chickadees prepare multiple nesting sites before the female chooses one, so we won’t know for a few weeks. Wherever they nest, the female will line the tree cavity with moss, soft plant fibers, feathers, hair and fur. She will lay 1-13 (usually 6-8) white eggs marked with reddish-brown spots. The female incubates the eggs and the male feeds her on the nest. Once the hatchlings are old enough to be alone for a short time, both parents feed them. Insects (including their eggs and caterpillars) and spiders comprise most of their high-protein summer diet. Black-capped chickadees also eat other small invertebrates, seeds, nuts and berries. They’ll visit seed and suet feeders in the winter. One cold afternoon, as I topped off our sunflower seed feeder, a cheeky chickadee landed on the edge of my filling-cup, snatched a seed off the top and flew into our arbor vitae hedge to either eat its treat, or cache it for another day.

Black-capped chickadees remain in Minnesota year round. They are common in much of the northern United States and most of Canada.

I enjoy the chickadees’ curiosity, high-energy antics and their melodious breeding calls, especially as winter drags on. Stay tuned to find out whether or not they nest in our apple tree.

Further Reading

Black-capped Chickadee; Audubon Bird Guide

Chickadee Delight. The Sleepy Eye Herald-Dispatch. February 3, 2020.

Haupt, Lyanda Lynn. The Urban Bestiary: Encountering the Everyday Wild. (First edition). New York: Little, Brown and Company, 2013.

January 26, 2021 by Beth

January Silence and Sound

Male cardinals (Cardinalis cardinalis) typically begin singing during mid-January in Minnesota. (I photographed this fellow on a sunny winter morning.)

The weight of winter silence presses on my ears. Heavy snowflakes drape tree limbs, topple seed heads and cover squirrel nests with a crystalline blanket. Falling snow absorbs the whir of auto engines, which pass almost noiselessly down the street. Even the incessant hum of the airport is muffled.

Suddenly, in the snowy hush a northern cardinal sings: “What cheer-cheer-cheer-cheer.” He repeats his joyful song four times and falls silent. His call momentarily illuminates the quiet. His red brilliance punctuates the black, gray and white of a January snowfall.

It is the first time I’ve heard a cardinal sing since last summer. In Minnesota, they typically begin singing in mid-January and will soon renew pair bonds and breeding territories. I welcome his upbeat melody that, along with the lengthening daylight, signals another milestone on the journey to spring.

Winter Crane Flies

Maple and basswood line the banks of the Mississippi River.

We hike along the Mississippi River as a cloudless sky, calm wind and a mild 52°F settle in for the afternoon. (The average high for Minneapolis-Saint Paul is 28°F today.) Blue jays, black-capped chickadees, and red-bellied woodpeckers call; gray squirrels rattle through the crisp fallen leaves. The river’s surface is unmarked by ripple or wave, and two Canada geese float a few feet from shore, honking softly to each other.

Winter crane flies (Trichocera species) swarm and mate on mild winter days.

Wherever rays of winter sunlight stream through bare branches of basswood and maple, the air shimmers with small swarms of winter crane flies. The low December sun ignites their wispy forms into sparks of gold. They zip around as energetically as though it were July.

Most types of crane flies are abundant in summer. Just a few species mature and mate in the winter. The swarms shimmering in the afternoon sun consist mainly of males. Females join them briefly to mate, and then lay their eggs in rotting leaves and soil. When not in flight on mild days, the adults rest in protected areas such as hollow trees and caves. (What could they possibly find to eat during a Minnesota winter? Not much. In fact, adults typically don’t eat at all! The larvae eat rotting vegetation, fungi and animal scat.)

They sparkle like tiny gold jewels in patches of winter sunlight.

Winter crane flies are most common in late autumn, early spring and sometimes on mild winter days. Today, they never stray from the sun’s mild warmth — nor do we! A rare Minnesota December day, indeed, and one to remember when winter weather returns.

Nature, Garden, Life

Author: Beth