Green Darner Migration

Common green darner female (Anax junius)

On a windy, warm September evening, the sun has set; the air is soft and dusky. Migration is underway, but not the avian sort. A few large common green darner dragonflies zigzag beneath the trees hawking insects. I look skyward and far above me, a river of swarming green darners surges — hundreds of them — straight south ahead of a cold front.

Born in Minnesota, these green darners migrate to the Gulf Coast of the southern United States and Mexico. When they arrive, they’ll mate and lay eggs to produce the next generation, which will migrate north in April or May. When they arrive here, they will mate and give rise to a new generation before dying. These progeny will hatch by late August and continue the cycle of migration and reproduction. 

But that’s not the entire story! Common green darners are present in the north all summer — so where did they come from? There’s a resident population that doesn’t migrate. They’re active and deposit eggs throughout the summer and autumn. However, their young, called naiads, won’t mature until the following spring. They will wait out the winter on the bottom of a pond, marsh or slow-moving river or stream.

Averaging 3 inches in length, and with a wingspan of 3.5 inches, green darners are among our largest dragonflies. This one also is a female. Males’ abdomens are bright blue.

Green darner adults eat mosquitoes, midges and other flying insects. The aquatic naiads feast on mosquito larvae and other aquatic insects, tadpoles and tiny fish. Green darners are eaten by spiders, large robber flies and birds such as kestrels.

Further Reading

Mead, Kurt. (2009). Dragonflies of the North Woods. Duluth, Minnesota: Kollath & Stensaas Publishing.

Smithsonian Magazine

UW-Milwaukee Field Station

Robins and Apple Blossoms

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.

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!

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.

Further Reading:

American Robin

Red-winged Blackbird

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.

Further reading:

Winter Crane Fly (Family Trichoceridae)

Winter Crane Flies

 

 

November Honey Bees and Asters

A honey bee (Apis mellifera) nectars in asters (Aster novi-belgii) on a summer-like November day.

Two weeks ago, temperatures bottomed out at 15°F and a winter storm buried gardens, yards and colorful-leafed trees under almost 10 inches of snow. Now, sun and a week of daytime highs around 74°F have awakened chipmunks, spurred American robins to sing and enticed honey bees from their hives. The bees found our last asters of the season. In a sunny location, and protected by an overhanging arbor vitae hedge on the north side, the pastel blossoms continue to open despite the early snow and frigid cold. What a gift — a sweet treat for the honey bees and an unexpected return to autumn beauty for us.

October Yellow (Move Over, Red!)

 

It’s easy to focus on the “can’t miss” colors of autumn’s oaks and maples. Orange and red dominate October’s landscape.  But, look more closely: Yellow’s quiet beauty slowly swells from a few bright pockets of heart-shaped basswood leaves, to entire bluff-sides wrapped in lemon, butter and gold of birch, cottonwood, maple and hickory. Woods that were deeply shadowed and cool green just a few days ago, now glow on a sunny afternoon. The air smells good — earth, ripe seeds and the slightly tangy scent of aging leaves — all part of autumn’s final act before winter spreads its monochrome blanket.

 

Butterfly Sampler

A painted lady (Vanessa cardui) basks in the sun on a roadside rock to warm its flight muscles.

Like miniature floating tapestries —  stippled, spotted and striped — they decorate gardens, yards and roadsides. Butterflies are plentiful this summer. Alongside the bumblebees, they pollinate many flower species and aid with seed production. But honestly, I love them more for their color, grace and elusiveness; for the joy they evoke in the eyes of children and the hearts of people of all ages. I delight in the first and last of every season — often a mourning cloak or red admiral in late April and a tortoise shell or red admiral in October.

Here are a few of the butterflies I’ve seen recently:

Eastern-tailed blues (Everes comyntas) are active May – September in the Upper Midwest and southern Canada.

This hackberry emperor (Asterocampa celtis) was attracted by sweet apple juice in my pail of apple windfalls.

Mourning cloaks (Nymphalis antiopa) overwinter as adults and are often the first butterfly active in April. They favor oak and maple sap; watch for them at woodpecker drill holes.

Two rows of yellow spots on the forewing distinguish the black swallowtail (Papilio polyxenes) from the eastern tiger swallowtail female dark form (Papilio glaucus).

This female monarch (Danaus plexippus) deposits an egg on the underside of a common milkweed leaf.

White admirals (Limenitis arthemis arthemis) are common in areas with aspen and birch. They prefer sap over flower nectar.

Red-spotted purples (Limenitis arthemis astyanax) are a southern subspecies of white admirals and the two often hybridize in the Upper Midwest. This one’s wings show that it has survived a bird attack.

Banded hairstreaks (Satyrium calanus) lay their eggs on oak trees. This adult rests on common milkweed in our garden.

Eastern tiger swallowtails (Papilio glaucus) favor nectar from Joe-Pye weed, blazing star and phlox.

Red admirals (Vanessa atalanta) migrate north in April and usually depart in October. Their caterpillars feed on nettles.

Black Eastern Tiger Swallowtail

An eastern tiger swallowtail black form female nectars on nepeta ‘Walker’s low.’

It’s late spring with the entire summer ahead of us. Nature’s greens are deep and full. Tiger swallowtails (Papilio glaucous) are on the wing now, the first of two times during the Minnesota summer. The first flight is typically in May-June and the second in July-August. The offspring of the second flight overwinter in their chrysalides.

I watch a bright yellow male patrolling his territory, repeating the same route through the large silver maples across the alleyway, over our apple tree and under my neighbor’s birch tree. He is quick to give chase to other males that trespass.

Eastern tiger swallowtail males are always yellow with black stripes and lack the wash of blue on the hind wings.

On this sunny, breezy morning, a black form female nectars in a sea of blue nepeta in our front garden. Her iridescent blue-on-black wings flutter repeatedly from one end of the garden to the other. She is full of energy and free of wing tatters and tears.

The female’s underwings are marked with bright orange spots and light blue scales.

Most eastern tiger swallowtails in Minnesota are yellow with black stripes. However, the female is dimorphic, or appears in two forms: the familiar black-striped yellow and a rarer black form washed with shimmering blue across its hind wings. Faint black stripes are often visible on the dark female.

Just a tiny percentage of females appear in the black form, especially this far north, but are  common in the southern United States. Why? Scientists think that the black form is a mimic of the pipevine swallowtail, which tastes horrible because the caterpillars feed solely on pipevine plants. (Think of monarchs and viceroys, another example of mimicry. Birds hate the taste of monarchs because they eat milkweed. Viceroys closely resemble monarchs, so birds often avoid them.) Pipevine swallowtails occasionally come as far north as Minnesota.

Interested in attracting eastern tiger swallowtails to your yard or garden? Favorite caterpillar foods include: chokecherry, ash, poplar, maple, apple and mountain ash. Adults nectar on many flower species including phlox, milkweed, Joe-Pye weed, blazing star, bee balm/bergamot and red clover.

Early Spring Native Flowers: Hepatica

This year, I look for spring close to home. I haven’t hiked in a nature preserve yet, and we’ve stayed home from our cabin. I miss those places, but I’m enjoying many simple delights right here, including a few native spring flowers. While bloodroot blooms fade, another spring native, hepatica, buds and opens.

Round-lobed hepatica (Hepatica nobilis) blooms range from white to purple in color.

Hepatica, liverleaf, or liverwort, is named for its leaves that are three-lobed and can be a brownish-bronze color (like the human liver) at winter’s end. Each spring, the fuzzy flower stalks push up through the old leaves to bloom in pastels ranging from white to purple. In Minnesota, hepatica can begin blooming anytime from early April into May — before the trees leaf out. Bees, early butterflies, beetles and flies pollinate the small flowers depending on how early they bloom. Fresh green leaves will grow up from beneath the flower stalks to remain until next spring.

Hepatica’s fuzzy flower stalks slowly unfurl to reveal the delicate flowers.

 

Hepatica leaves are three-lobed. The previous year’s leaves are often brownish-red or bronze and reminded earlier people of the human liver. (Hepatica is from the Greek word for liver.)

 

New green leaves grow beneath the flowers and will last all season.

In it’s natural setting, hepatica often grows under oak trees — that’s where I first spotted it peeping out among tattered brown leaves one warm April day at our cabin. (I purchased the hepatica in my garden at a local nursery.) It is a woodland wildflower that prefers full spring sun that becomes dappled sun as the trees leaf out. Two species are native to Minnesota — round-lobed and sharp-lobed — and are very similar in appearance. It’s also very well-behaved, so a gardener needn’t worry about hepatica overtaking the garden!

This week in the yard, besides the blooming hepatica, bloodroot leaves unfurled and increased in size as seed pods swelled. Many tiny native bees, and a not-so-tiny queen two-spotted bumble bee, pollinated the spring flowers. A wave of hermit thrushes ate insects and seeds in the backyard most of the week before continuing north to their nesting grounds. 

As the bloodroot blossoms (Sanguinaria canadensis) wilt, the leaves unfold and the seed pods begin to swell.

 

A queen bumble bee (Bombus bimaculatus) hovers above glory-of-the-snow (Chionodoxa luciliae) blossoms.

 

A hermit thrush (Catharus guttatus), one of the most ethereal songsters I’ve heard, rests on its journey to northern Minnesota and Canada.

Nesting sites are a hot commodity locally, too: A female mallard sits on her nest completely hidden in our neighbor’s daylily garden. Robins nest in arbor vitae behind the garage and cardinals nest in a neighbor’s small evergreen shrub. Each day, the cardinal pair visits our garden where the male gently feeds his mate. In a few weeks, the begging calls of this year’s first fledglings will fill the air. I look forward to seeing their plump, downy bodies following their parents around the garden!

 

 

October’s Gifts

I began cutting back our garden on one of the few warm days before last week’s hard frost. It was sunny and windy. Yellow maple and apple leaves sailed through the yard. Blue jays called raucously. Chimpmunks and squirrels ate nuts and stashed others for the winter. A few flowers still bloomed, though most now sported full seed heads. Among the blooms were the last native bees and butterflies of autumn. Here are a few of late October’s simple gifts:

A tiny green bee (Agapostemon virescens)) looks for nectar in a blanket flower blossom (Gaillardia pulchella).

Common bumble bees (Bombus impatiens) are a hardy native bee. This one looks for nectar on a native sunflower (Helianthus spp).

A painted lady butterfly (Vanessa cardui) suns itself on a native sunflower.

This tiny garden spider built a large web among some spent daylily stalks.

Thin-leaved coneflowers (Rudbeckia triloba) resemble miniature black-eyed Susan’s and bloom into early November.

The seed heads of the native perennial white snakeroot (Ageratina altissima) are soft and fluffy.

These spent purple flowers of Joe-pye weed (Eutrochium maculatum) will ripen to a mass of soft, brown seeds.

Common milkweed pods (Asclepias syriaca) split open and released their soft, parachute-like seeds.

An eastern chipmunk (Tamias striatus) enjoys the mild afternoon on our back stoop.

An albino eastern gray squirrel (Sciurus carolinensis) snacks on nuts from its perch under the arbor vitae hedge.

I love hearing the sassy blue jays (Cyanocitta cristata) call when most birds are quiet in the fall and winter.

Beacon apple leaves (Malus domestic ‘Beacon’) glow in the afternoon sun.

Quaking aspen leaves (Populus tremuloides) quiver and rustle in the smallest breeze creating a peaceful sound.

Red maples (Acer rubrum) smolder on crisp, late October afternoons.

Brightness in the Gloom

Maple and ash leaves contrast with gray skies and sidewalks on these gloomy days.

Cold, rainy, dark. These adjectives capture the weather and mood of the past three weeks here in Saint Paul, Minnesota. No blue October skies and warm afternoons so far, and none in sight, according to the National Weather Service. I hear lots of complaints from people to the tune of, “My grass is lush green, but I am so crabby;” or, “I just want to read and sleep all day;” or, a straightforward “I am so depressed!”

I don’t like it either and I understand these sentiments. Most of all, I miss gardening and walking outside. As dank as it is, my husband and I have walked in the rain a few times and I gardened in it for a half hour last Sunday. I feel happier and more energetic after I go out to garden or walk, even though I get wet. I’ve noticed others doing the same — students at morning recess in the mist, gardeners cutting back their spent plants, even a few people trying to mow saturated lawns in the persistent drizzle.

When we walked yesterday, I was struck by the contrast between the heavy sky and the splotches of color lighting up the gray sidewalks — maple, birch and ash leaves — their hues more vivd for being wet. The rain and strong winds tore down the leaves prematurely, but I am grateful for the beauty and glow of their colors on these gloomy days.

The leaves of the white ash (Fraxinus Americana) turn orange, red or purple in autumn.