Why is Fall the best of the four seasons?

Number 1 (for me) has to be the colors of Fall — they’re bright, warm, and make us (well, me, especially) want to be outside communing with Nature.

Beaver River Falls, Beaver Bay, MN

How could you resist a walk along this river admiring the fall foliage?  I think this is the last waterfall before the Beaver River empties into Lake Superior (near Beaver Bay).

Number 2 might be the temperature — warm days, cool nights, always changing, something for everyone…


Perfect temperature for canoeing down the Mississippi River


Or for studying outdoors in a warm, sunny space. If you get too warm, you can just move into more shade.

Number 3 is a little more abstract:  the effect of short daylength on our brains makes us a little lazy and lethargic (or is it the warm sunshine?); long nights give us the perfect excuse to get more sack time.  The end result is we might feel more rested and less stressed (or is it the warm, bright colors of fall that do that?).


Beginning in the Fall and continuing through the winter, extended periods of sleep are common in some human cultures. Drawing from the British Medical Journal article on Human Hibernation

Number 4 is the fact that Fall is harvest season — it’s a time of plenty, for both humans and animals.

Sometimes the "harvest" is almost too big to carry...

Sometimes the “harvest” is almost too big to carry…

Scads of berries, nuts, seeds, and fruits are available for primary consumers, along with a large supply of young, naive prey animals for the predators.


With their high sugar content (30%) these berries are a great resource for migratory birds like this Yellow-rumped (Myrtle) Warbler. Even the waxy coating on the berry can be utilized by the birds, whose digestive systems have been primed to secrete an enzyme to break down the wax esters.

At other times of year, consumers most likely face food shortages, with scanty plant and animal productivity during winter and spring, and limited food supplies during much of the summer as plants and animals are growing the next generation.

I’m sure there are many more reasons why Fall is the best time of year — or do you disagree?


Fall color along the Mississippi River. Click on the image for a larger view.

water power

More than 200 rivers drain the north country in the Minnesota, Wisconsin, and Ontario, Canada feeding their water into Lake Superior, and some of these rivers cut through deep layers of basalt that form the Lake Superior basin and end in spectacular waterfalls.


Three waterfalls in succession along the Cascade River dump their tea-colored water into Lake Superior.


Slowing the shutter speed down gives the impression of the flow of a coffee milkshake over the falls.


The volume of water pouring over the hardened basalt surface is powerful enough to carve deep gorges over time.

Title cascade-river-and-falls- Caption

Beyond the last waterfall, the river empties calmly into Lake Superior, tea-colored water mixing with the deep blue of the lake.

Colorful Northwoods in the borderlands

Even the dull gray skies couldn’t diminish the amazing color in the landscapes along the north shore of Lake Superior this week.  Although the maples had largely dropped their red and gold leaves throughout the inland forests, the golden glow of birch and aspen leaves more than made up for it.  You get a really good idea of just how dominant these trees really are in the total landscape when you see them highlighted against the evergreens.

colorful-northwoods-northeastern MN

Where the forest meets the shoreline of Lake Superior at the very tip of the arrowhead that makes up northeastern Minnesota. This scene is about 1 mile from the Canadian border.

colorful-northwoods-northeastern MN

The Pigeon River marks the boundary between the US and Canada in this part of Grand Portage State Park.  Across the river is Canada’s Pigeon River Provincial Park.

colorful-northwoods-northeastern MN

Hello Canada!  The Pigeon River may have moved its channel in this area, because a survey marker for the border was located not far from where my husband is sitting.

colorful-northwoods-northeastern MN

It’s quiet in the Northwoods as we hike along — nothing to distract us from noticing the colorful display around us as we hike.

colorful-northwoods-northeastern MN

Round birch leaves on the ground make it look like the hiking trails are paved with gold coins.

the cutest killer

With their small bodies, short noses, pert ears, and bright, brown button eyes, there is no doubt that American Martens (a member of the weasel family about the size of a mink) are cute…


Cute enough to be a pet?

But these feisty little hunters will give chase to Red Squirrels, mice of all sorts, even Snowshoe Hares, and they hunt both day and night, depending on season and weather, being active as much as 60% of the day in the summer.  They are also important seed dispersers of the fruits that pass through their digestive tracts, some of which (e.g., Alaskan blueberry and huckleberry) will germinate far more easily having been treated with a little Marten stomach acid first.


A tree perch is a great place from which to scope out this marten’s next meal.


Hmm…what shall it be…


How about a nice plump chipmunk?

Although Wikipedia doesn’t mention chipmunks as possible prey of martens, they are rather slow moving, comparatively easy to catch, and also rather common in the birch-balsam fir forest in northeastern Minnesota that Martens also inhabit.


Sitting out in the open where some furtive predator (like that cutest killer, the American Marten) can see it might just be a fatal mistake.


Activity like this, with two chipmunks chasing each other, and running around on the asphalt walking path must make them very attractive to hunters like the marten.


Run away little chipmunk…

All photos by Steve Chaplin, who found the Marten by accident while trying to photograph a Ruffed Grouse in Grand Portage State Park in the northeastern most corner of Minnesota, while I was busy photographing waterfalls.

the North Shore’s spectacular show

I can’t believe the north shore of Lake Superior could be any more photogenic than it is this week, at peak color with blazing golds of birches and aspens, blending with reds of the few remaining maples and some early turning oaks.  Throw in some green evergreen trees for contrast along with the slate gray-black of those amazing rocks along the shore, and some blue Lake Superior water, and you have quite an amazing landscape.



Red berries of Mountain Ash stand out against the green, orange, and gold leaves.


the iconic Split Rock Lighthouse surrounded by fall color


Clouds reflected in pools of water along the shoreline rocks



One of the many waves of migratory birds that has arrived in the Twin Cities area in the past couple of weeks was Robins — a bonanza of Robins — a “robinnanza”.  These are not your usual noisy, chattery backyard robins;  they are instead secretive, quiet, stealthy birds that fly silently through the forest and gang up together for bathing in small forest streams.


Big and beautiful, with their newly molted and bright-colored orange and gray plumage — about two dozen of them crowded in a small forest stream for a bathing party.


It’s a daily (or more often, perhaps) ritual for these birds, especially in this delightful babbling brook.  Cold water is no deterrent.


Now feeling so much cleaner…


Having gotten rid of all the dusty dirt under those brand new feathers, Mr. Beautiful hops up on a branch to dry.

Previously, I wrote a post querying why readers thought Robins bathed so much, and one reader suggested it was because they dig around in the dirty leaves so much.  Indeed, there was an ample display of that behavior near the stream bank, where Robins were furiously poking into and throwing leaves up in the air as they explored what lay beneath.

american robin

Tossing leaves in the air from the muddy ground probably deposits quite a bit of dirt on the thrower.

I poked at a few leaves myself, and found some spiders and mealy bugs crawling around under them, so no wonder the Robins have congregated in this rich hunting ground near a lovely bathing spot.


the forest stream last March in this same spot, just as the watercress was beginning to grow


Warm days, cool nights, sometimes rainy and blustery — that’s fall.  You never know what it’s going to be like because the weather changes day to day, or even from morning until evening.  But the combination of short daylength (less than 12 hrs of daylight) and very cool nights starts the color change in the vegetation that we love to see.  (For an explanation of how that color change happens — click here.)


Not all plants are as sensitive to the daylength and temperature cues — making the fall season a long and colorful display.


Maples and aspens are some of the first to show their fall colors, and oaks are one of the last, making the forest a kaleidoscope of green, yellow, red, and orange.


A few remaining flowers like this New England Aster can still be found in the prairie, but there are few insects around.


Milkweed pods open to disperse their airborne seeds.


Yellow-rumped Warblers are one of the more abundant migrant species, found and heard in almost every habitat — even the prairie.


Waves of warblers (like this Nashville Warbler) move through with the weather fronts in the fall. But these are wary little birds, and even harder to photograph in the fall when they are feeding ravenously to replenish their migratory fat supply than they were back in the spring when they came through on their way north.

ant farming?

True or False:  among all the species in the animal kingdom, only humans are known to domesticate other animals for their own use.

You can probably guess from the title of this post that the statement may be false.


Is this ant just a random passerby, or is it performing some other function sitting near this dense patch of yellow aphids clustered on a milkweed stem?  There is a spider hovering in the top right corner — is the ant there to protect this aphid colony?

There are numerous reported examples of the ways in which the highly organized society of an ant colony manipulates certain species of sap-sucking bugs (Hemipteran species) to harvest the sugar and protein in the bug’s excreta.


Aphids feed on plant sap by sticking their proboscis directly into the phloem tubes that carry photosynthesized sugars from the leaves to other parts of the plant.  As the bugs fill up with plant sap, clear liquid droplets called “honeydew” form (top right of image) at the tip of their abdomen.  Ants can harvest the energy in this “waste” product for their own benefit.


Ant feeding on aphid “honeydew”. Photo by Charles Chien,

Ants protect their “herd” from predators by swarming them and driving them away, they transport the herd to new leaves on which to feed, they move them to sheltered locations during downpours, all to maximize the nutrient-rich output of the herd’s excreta.  Ants also excrete a substance that reduces movement of their herd, so that they stay put in one place, and they have been observed to bite off the wings of the breeding females so they don’t disperse from the feeding area, but instead produce more offspring in situ.  So, it really is farming…in quite a sophisticated way.  This is illustrated beautifully in a video on antark.net — please click on this link to see it:


Stocking up for the winter

We wait all summer for New England Aster to show off its beautiful lilac-purple to bright pinkish flowers, and it never disappoints.


Dense clusters of flowers attract a variety of pollinators in the fall with bright-colored flowers, lots of pollen, and nectar.

Besides being a very attractive addition to the garden, New England Aster is an important late-season resource for pollinators, especially Monarch butterflies as they fatten up before fall migration.  Flower nectar and pollen are energetically harvested by lots of bee species, as they top off their hive or overwinter nest supplies.


Honeybees, which I rarely see in my backyard, were numerous on this patch of New England Aster and were collecting both nectar and pollen.  This bee already has good-sized pollen baskets on its rear legs.


Common eastern bumblebees (center) were probably the most common bee on these flowers, but shared the resources with at least five other species of bees and a couple of species of Syrphid flies (hoverflies), seen in top left.


Both a large bodied (about as big as a honeybee) and a smaller bodied hoverfly worked the flowers. These are bee mimics, presumably avoiding predation by pretending to be fearsome stingers.  However, they have no weapon defense except their coloration, and have only one pair of wings (unlike bees and wasps which have two pair) with which they hover over and between flowers.


A smaller green sweat bee is unperturbed by the far larger bumblebee foraging next to it. There isn’t really much competition when there are so many flowers in this patch of aster.


I assume bees can smell or taste the presence of nectar in a particular flower, so some of the flowers got worked over very intensively by some bees that probed their tongues into every recess in the collection of disk florets in the orange center of the flower.

Honeybees and bumblebees are particularly good dispersers of flower pollen, as it easily attaches to the spines on their legs or hairs on their heads and bodies, as seen in the photo above.  The smooth exoskeletons of the body and legs of the hoverflies and sweat bees make them far less effective in transferring pollen from one plant to another.

If you live east of the Rocky Mountains where New England Aster grows, you might have noticed the profusion of aster flowers that has suddenly occurred over the past couple of weeks.  I assume synchronous blooming like this over widespread areas is probably triggered by the changing daylength, and is advantageous in pulling in large number of pollinators to maximize pollination and seedset in these asters.

the birds and the bees

In late September, there are far fewer flowers for the bees and birds to visit — the bees to collect those last remaining dregs of pollen and nectar before the snow flies, and the birds to harvest what seed might still be remaining in flowers that bloomed more than two months ago.

Giant Hyssop is a favorite of the bumblebees these days; its profuse blooms always attract a variety of pollinators, especially when the sunshine can get through the clouds to warm up the air a little.


The bumblebees generally start at the bottom of the flower head and spiral around upward walking over some flowers, poking their antennae into others, and every now and then inserting their entire head into a particular flower to glean whatever nectar lies at the bottom of the floral tube.


When the bee gets to the top of the raceme, it makes a short flight over to the next one, beginning again at the bottom and working its way up to the top.  

Flower stalks already being worked by one bee seem to be off-limits; there would probably be little nectar left in the flowers in that case.  But every so often, a couple of bees try working the same flower patch…


Looks like better foraging on the hyssop flowers than this very attractive but apparently unrewarding purple flower that I planted but have no idea what it is.



oops, this one is taken


This isn’t a tandem bumblebee hook-up; the one on top (right side up) is actually flying toward the camera, away from the bee that was originally foraging on that stem.

Overlooking this busy bumblebee activity was a mixed flock of Goldfinches, House Finches, and White-throated Sparrows, all of which were much more interested in the seeds left in the wildflower garden than the flowers there.


Their bright red color has faded to a rosy hue with the fall feather molt. This little male spent several minutes picking out lilac seeds from dried up remnants of flower clusters.



A juvenile White-throated Sparrow watched what the House Finches were eating, but didn’t seem interested.