What’s in this Season?

Autumn is a season of change in Minnesota. Migrating birds flee to warmer climates. Bears and other hibernating critters prepare for a season hunkered down. And the most spectacular change of all—Minnesota’s tree canopy turning from its summertime green to a kaleidoscope of yellow, red, orange and brown. Don’t hesitate to get outside and enjoy nature’s signs of change—this season won’t last long.

Fall Color

Minnesota’s spectacular fall colors make it an autumn destination. Starting in late September, the Northwoods gradually shift in color, spreading southward throughout October. 

Many of those colors have been present in leaves during the entire growing season but masked by chlorophyll, the light-absorbing green pigment that is essential for photosynthesis. 

When the days shorten in the fall, photosynthesis slows and eventually ceases, causing deciduous trees to stop making chlorophyll, allowing other pigments in leaves to become visible. Carotenoids are the pigments responsible for yellows, oranges and browns; anthocyanins create reds and purples; and mixes of the two pigments result in bronzes and deeper shades of orange.  

Location, weather and type of tree determine when this color change takes place. In the Twin Cities, peak fall color usually occurs in the first or second week of October. However, timing can change from year to year, influenced by temperature and rainfall. Drought causes less brilliant colors and trees in dry years drop their leaves earlier. At any one location, tree species also determine fall color. Ash are known for their early color change. Aspen, cottonwood and maple often follow, and oak change color later. Conifers, of course, don’t change color or drop their needles–except for tamarack (also called larch), the only conifer in Minnesota that changes color (from green to yellow) and drops its needles in the fall.

Stay tuned to the Minnesota Department of Natural Resources fall color finder to find the best times to observe fall color.

Hibernation Begins

Winter doesn’t officially begin until the solstice on December 21, but by November, cold temperatures have already induced many mammals that are not active during winter to begin hibernation. Black bears are the largest mammal in the state to undertake this extended period of dormancy and most bears are “asleep” in their dens by November. 

Bears can wake up from hibernation if disturbed in their dens and female bears (sows) give birth to their cubs during January and February. Sow bears nurse and care for their newborns during hibernation. 

Bears are extraordinary in that they recycle their metabolic waste during hibernation, using it to make new protein. They are the only mammals known to do this. It is this unique ability that allows them to go months without urinating, eating, drinking or defecating. Bears even redeposit calcium onto their bones during hibernation, compensating for the loss of bone mass that would otherwise result from months of inactivity. 

Bears are sustained by their fat reserves during their many months of hibernation. When they emerge from their dens in the spring, bears may have lost 25% to 50% of their body weight. The need to build fat reserves to make it through winter causes bears to eat voraciously in the fall, a behavior called hyperphagia, when bears gorge themselves on berries, acorns and other foods. If these natural crops are in short supply, hungry bears may become nuisance bears when they wander near homes to raid bird feeders and trash cans or forage in farmers’ fields of corn and sunflowers. 

Winter in Minnesota is cold and snowy, but that should not keep you from exploring the outdoors! The trails are quiet and chances are, you may be the only one braving the elements. Embrace the solitude and soak in the mental health benefits the snowy forests and icy lakes have to offer. Bundle up and grab your snowshoes. There is so much going on in nature even on the chilliest days.

Birds

Winter is the best time for birding because there are no leaves on the trees. It makes spotting birds much easier! Although many birds flee Minnesota during the cold winter months, we have some year-round resident birds that you can surely spot around the state. In some winters, birds that are uncommon in the state arrive unpredictably in large numbers – a surprising movement called an irruption. Feeders that normally attract only the usual chickadees, juncos and blue jays suddenly are visited by colorful yellow and black evening grosbeaks, purple finches, redpolls, pine siskins or pine grosbeaks. These winter finches are hard to overlook, although their visits may be brief and sporadic—they are wanderers seeking seeds to sustain them through the winter.  A good place to look for winter birds is Sax-Zim Bog, 300 square-miles of ideal habitat crisscrossed by county roads approximately 35 miles north of Duluth near the town of Cotton.

Wildlife

A snow-covered landscape makes Minnesota optimal for spotting wildlife in the winter months too. And soft snow holds evidence of wildlife movements for observers who are willing to look for it! Keep an eye out for the tracks of deer, fox and even coyotes. 

If you have especially keen eyes, you may spot some critters that would rather not be seen. The fur coats of snowshoe hare, white jackrabbits and weasels all turn white to blend in with the snow in the winter months!

The signs of spring are always welcome after a long Minnesota winter. From early spring flowers soaking up precious sunlight to critters frantically seeking a mate, spring is a time for beauty and renewal. Enjoy the trickling waters of a slowly thawing river or lace up your boots for a tromp along a muddy trail. Take time to observe what’s around you—hints of spring will appear before the snow has even melted. 

First Blooms

Woodland wildflowers must be early risers. They peep out of the decaying leaf litter before the trees above them have a chance to shoot out their sun-blocking leaves. 

Few flowers that take root in the forest bloom earlier than the aptly named snow trillium. Spring’s large and showy trilliums are familiar wildflowers, but snow trillium is often overlooked both because it blooms so early and because it is rare. It is a species of special concern in Minnesota. It’s also the state’s smallest trillium—the flowers may be only an inch across.  

On the prairie, the pasque flower is one of the first to bloom. You may even see it blooming out of the melting snow. Pasque flowers thrive on prairies with sandy soils, like River Terrance Prairie SNA and Agassiz Dunes SNA. Nature writer Aldo Leopold wrote in A Sand County Almanac, “The chance to find a pasque flower is a right as inalienable as free speech.” Find a pasque flower and know unquestionably that spring has arrived on the prairie. 

Flying in Love

Spring is the season to witness incredible courtship displays as birds across Minnesota pursue mates.

Bald eagles perform spectacular aerial displays: circling high in the sky, then locking talons and tumbling downward, separating only moments before they would crash. Courtship flights occasionally happen as late as March, but many Minnesota eagles nest early and are incubating eggs by mid-February. Eggs hatch after 35 days and the young typically stay in the nest for another 8 to 14 weeks. 

In April Minnesota’s tallgrass prairies host an impressive display of courting birds at the booming grounds of greater prairie chickens. Male prairie chickens compete for the attention of hens by performing a “dance” that includes stamping their feet, fanning their tails, hooting, gurgling and inflating throat pouches to create an odd booming call.  

The American woodcock, a squat shorebird with long bills and stubby legs, can be heard courting in the forest. Listen at dusk for the male woodcock’s nasal peent call repeated every few seconds until the bird launches into an aerial display, easily recognized by its twittering wing sounds as it spirals upward. While the bird is airborne, move quickly to where you heard its peent calls, then sit quietly. You may be rewarded by the displaying woodcock swooping down to within a few feet of you to begin again its peenting calls. Stay very still and enjoy the show.

Summer: it’s what makes the Minnesota winters worth it.

Throughout the season, the state is abloom with wildflowers. Every few weeks, a new suite of plants is opening delicate petals to the bees and butterflies seeking out nectar. 

The staggered blooms are key for supplying pollinators with nutrition throughout the entire summer. In June, lady’s slippers and pitcher plants peek up in wetlands. In July, coneflowers and milkweed flowers begin to bloom across the prairie. In August, asters, gentian and blazing star pop open their purple blossoms. 

White pelicans

There’s so much more than just flowers to behold in nature in a Minnesota summer. Summer is also a good time to look for white pelicans. These striking birds, with wingspans that can stretch nine feet, are impressive when soaring in groups. Unlike the familiar brown pelican found along ocean coastlines, these birds don’t dive from the air to catch fish. Instead, they swim at the surface, hunting cooperatively in groups, dipping their large bills and pouches beneath the water to capture fish.

Cicadas

July and August bring the hottest days of the year in Minnesota. A hallmark of these “dog days of summer” is the whining call of cicadas, a rising crescendo heard often during the most sweltering moments of the afternoon. Cicadas are common wherever there are shade trees, living high in the branches where they’re not easily seen. But their call is hard to miss. It’s made by males to attract mates, and when many males call from one location, they create a loud, buzzing chorus.