At the heart of Severson Dells Nature Preserve is the valley of Hall Creek, with its weathered bedrock cliffs standing as mute testimony to the power of moving water. Thousands of years ago, glacial meltwaters carved the valley, exposing the ancient dolomite (a kind of limestone); today Hall Creek (or Mosquito Creek as it is called out on some maps) meanders through the valley, flowing year-round, draining farm fields that occupy areas north of Montague Road and carrying the water to the Rock River.

 Hall Creek, flanked by dolomite limestone cliffs

Hall Creek, flanked by dolomite limestone cliffs

Within the field of physical geography, more specifically fluvial geomorphology, Hall Creek would be categorized as a ­first-order stream or a headwaters stream. What does that mean? Well, human beings are always sorting, classifying, or categorizing things. Taxonomy generally refers to the classification of organisms, but the same principles apply to other things, including streams. Stream order is a way of sorting waterways—from small headwater streams to mighty rivers.

To explore this idea, we first need to settle upon a definition of stream. We’ll use the term in a generic sense to refer to any body of water that flows, generally confined within more-or-less well defined banks.

Early classification systems tended to be subjective and therefore inconsistent. Classifications based upon morphology (such attributes as gradient, sinuosity, width-depth ratios, etc.) had limited application because stream characteristics may change back and forth across space. (Sinuosity, in case you were wondering, is defined as the ratio of channel length to valley length.) In the words of hydrologist David Rosgen, “One consistent axiom associated with rivers is that what initially appears complex is even more so under further investigation.”

So, based on work done in the middle 20th century by researchers named Horton and Strahler, stream order can be quantified by what is known as a Strahler Number (or Horton-Strahler Number). It works like this. A perennial headwater stream is a first-order stream. Below the confluence of two first-order streams is a second-order stream. Below the confluence of two second-order streams is a third-order stream. This continues until the 12th order.

(Note that adding a first-order stream as a tributary to a second-order stream does not elevate the second-order stream—it continues as a second-order stream and the first-order stream ceases to have its separate existence. It is only when encountering another second-order stream that the order is elevated to third. And so forth.)

 an illustration of the Strahler numbering system

an illustration of the Strahler numbering system

Generally, first-, second-, and third-order streams can be considered small or headwater streams; those ranked fourth through sixth are considered medium-sized streams; those ranked seventh through 12th are considered to be rivers. For example, the Ohio River is an eighth-order stream; the Mississippi is a tenth-order stream; the Amazon is a 12th-order stream. Some 80 percent of the world’s waterways are small (first- to third-order) streams.

To further confuse things, there is an alternative method, the so-called Shreve method, which is additive: the confluence of a first-order and second-order stream yields a third-order stream; the confluence of a third-order and second-order stream results in a fifth-order (or fifth-magnitude) stream. Because the Shreve method counts all upstream tributaries they may be referred to as magnitudes rather than orders.

 An illustration of the Shreve numbering system

An illustration of the Shreve numbering system

So what about all the other names we have for streams (like creek or brook)—do they have specific meaning? One way of thinking about it is expressed in an old adage:  “You can step over a brook, jump over a creek, wade across a stream, swim across a river.” Not very scientific, though.

As it turns out, some of the place-names (toponyms) widely used for these flowing bodies of water have certain regional or cultural affiliations. For example, words like rio and arroyo are of Spanish origin and are commonly used in the Southwest. Here in the upper Midwest we have several other words for streams, mostly borrowed from North, South, or Midland sources.

Brook, for example, is widely used in New England and elsewhere in the North. Branch, on the other hand, is used mostly in the South. Run is a Midland term. Such words may also be used to describe the physical milieu of the stream. In that context, a run implies a swift flow, perhaps across relatively steep terrain, with energetic action, while a branch or fork may suggest divisions of a stream, often in flat terrain.

Creek originally referred to coastal inlets and tidal estuaries, but now is ubiquitous and, much like stream, might be used in the generic sense. Where pronounced, “crick” it likely is of southern origin. Watercourse actually refers not to the flow of water but to the channel it occupies.

So, looking at our place-names, it would appear that whoever had naming rights used terms familiar to them—likely terms that reflected their personal geographic and linguistic histories.

No matter what we name our streams, or how we rank and categorize them, the fact of the matter remains that surface waters are vital components of our hydrological systems and water quality is essential to life. We depend on our waterways to alleviate flooding, recharge groundwater, maintain wildlife, and generally enrich our lives. In fact, streams and rivers do help to sustain us.

P.S., for those readers who would really like to geek out on a map and commentary regarding toponyms applied to streams in the continental United States, I invite you to spend some time here:


The naming of plants is a curious business. When I first studied botany it was explained to me that it would be necessary to learn binomial nomenclature because the common names given to plants could be notoriously confusing. A plant could go by one name in one part of its range and be called by a different name elsewhere in its range. Ah, but the true scientific names are universally applied and—so it was explained to me—those names don’t change.

But they do. In fact, over the past few years there have been wholesale changes to the botanical names of a great number of native plants. But that’s not what I’m blogging about today. Today I want to address some common names of plants.

Some common names employ the modifier, “false.” For example, the prairie wildflower that I prefer to call obedient plant (Physostegia virginiana)—for the compliant nature of its corollas, which may be turned as if on a swivel to point in one or another direction—also has been known as false dragonhead. Long ago, one of my teachers shared his disdain for the “false” modifier, stating that each plant is an organism worthy unto itself, deserving of its own identity and not to be relegated to the status of a false or inferior shadow of some other plant species.

 True obedient plant or false dragonhead? ( Physostegia virginiana )

True obedient plant or false dragonhead? (Physostegia virginiana)

Similarly, feathery false Solomon’s seal (Maianthemum recemosum) and starry false Solomon’s seal (Maianthemum stellatum) were so named because of the resemblance of their foliage to that of the “true” Solomon’s seal (Polygonatum canaliculatum). I prefer to call them feathery Solomon’s plume and starry Solomon’s plume. “Feathery” because of the appearance of the terminal inflorescence, the raceme at the end of the growing stem; “starry” because of the star-like aspect of the widely spaced individual flowers and the star-shaped pattern that appears on the ripening fruits.

Other common names also correlate to their botanical names. Pale spiked Lobelia is Lobelia spicata. A more arcane example would be silky wild rye (Elymus villosus), whose delightfully soft, silken hairs adorn the surface of each leaf blade. (Botanists refer to a surface covered with long, straight, soft hairs as “villous.”)

Sometimes I wish that more common names reflected the botanical nomenclature. Take for example the rustic name of poke milkweed (Asclepias exaltata). Given the specific epithet, wouldn’t it be better to call it the exalted milkweed? For that matter, what about swamp milkweed (Asclepias incarnata)? We could call it milkweed incarnate.

 exalted milkweed? ( Asclepias exaltata )

exalted milkweed? (Asclepias exaltata)

 millkweed incarnate? ( Asclepias incarnata )

millkweed incarnate? (Asclepias incarnata)

Locally, two species of Impatiens grace our moist-soil habitats. Spotted touch-me-not (Impatiens capensis) also goes by the name of orange jewelweed and occurs in a wide variety of moist habitats, from full sun to partial shade. Pale touch-me-not (Impatiens pallida) also may be called yellow jewelweed and is more likely to found in wet woodland pockets. I prefer to call them jewelweeds because “touch-me-not” strikes me as a bit off-putting, although the name derives from the plants’ seed-dispersal strategy:  ripe seedpods are spring-loaded and the slightest touch will cause the pod to burst open with ballistic force, hurtling the seeds some distance from the parent plant. In fact, the name of the genus, Impatiens, derives from the Latin for “impatient,” referring to the sudden bursting of the ripe seed capsules.

The plant sometimes known as green-headed coneflower (Rudbeckia laciniata) is not in the same genus as the gray-headed coneflower (Ratibida pinnata), which is also known as the yellow coneflower. Neither share the same genus as the purple coneflower (Echinacea purpurea) or pale purple coneflower (Echinacea pallida). But back to Rudbeckia laciniata, which is in the same genus as black-eyed Susan (Rudbeckia hirta) and brown-eyed Susan (Rudbeckia triloba); rather than the somewhat pedestrian name of green-headed coneflower, I much prefer the more lyrical appellation, wild golden glow. Now that’s an evocative plant name, and one befitting the majesty of this streamside species.

I will humbly defer to my betters when it comes to scientific names, but when more than one common name might be applied to a given local species, I am inclined to select the more lyrical or evocative appellation. As Ursula K. LeGuin once wrote, “For magic consists in this, the true naming of a thing.”

Christmas in August

CSI Rockford, watch out!  The naturalists at Severson Dells will give you a run for your money!

Last Friday, August 31, one of the Forest Preserve staff brought us an owl pellet that he found up by the farm.  It was quite large, with long fur attached on one side, and a very clean jaw bone sticking out. 


Now, I love dissecting owl pellets – they are like little furry Christmas presents, full of goodies and you never know just what you might find.  I’ve dissected probably hundreds of pellets over the years, mostly with students, but a few on my own.  The majority of the time one finds rodent bones in them, which is no surprise - mice and voles make up a huge part of an owl's diet.  A handful of times I’ve found shrew bones (red and black teeth always give them away).  I’ve found bird skulls maybe three or four times.  Jerusalem cricket mandibles were probably the most exciting thing I found…until this last week.

As soon as I saw that pristine jawbone sticking out the side, I knew we had something special – that was no rodent jawbone.  The molars were long and pointy, and the teeth went all the way from the back to the front of the jaw (rodents have a space between their molars and incisors).  But it had to be a "small mammal" – the bone is less than an inch in length.


I decided to do a Facebook Live video while dissecting it – a new challenge for me.  Got my phone set up, balanced on bundled knotweed stalks in lieu of a tripod, and off I went.  Each piece I pulled out was exhibited and pondered over.  Some bones were obvious: femur, shoulder blade, ribs, vertebrae.  There was the pelvis with a femur still attached.  There were two jaw bones (sadly, no skull). 

And then I found a foot.


Now, this wasn’t just any old foot.  Most small mammals’ feet are composed of numerous tiny, fragile bones.  If you are lucky, you find them still articulated.  This foot, however, was huge.  In truth, it was the claws I found first – enormous claws attached to a large, wide foot with sturdy, broad bones.  I was left with no doubt as to what I had:  a mole.

I quickly looked up online to see what species of moles are found in our region, and was disappointed to find only one:  the eastern mole (Scalopus aquaticus), also called the prairie mole.  Still, it made the choice pretty easy.

Two mysteries still remained, however.


One:  what in the world were these two very thick bones that I found?  At first I speculated they might be part of the skull, based on what I could see in the morphology of the first one I found; once the second one, identical in every way, showed up, this theory was out the window.  There was no way these were part of the skull – they were definitely two separate bones.

 This image is from the Natural History Museum, online.  I drew the arrows in to show you where the humerus is located on each leg.  This is a European Mole, not an Eastern Mole, but the parts are still essentially the same.

This image is from the Natural History Museum, online.  I drew the arrows in to show you where the humerus is located on each leg.  This is a European Mole, not an Eastern Mole, but the parts are still essentially the same.

Today’s search online for a mole skeleton provided the answer:  the humerus!  The mole’s skeleton is quite unlike those of other small mammals when it comes to the front legs, and considering that this animal is using powerful front legs to move mountains of earth every day, that shouldn’t come as a surprise.  The thickness of these bones attests to the strength they must have to support the mole’s fossorial lifestyle.  The shape of the bones, however, still leaves me saying “huh!” – the humerus for most mammals is long and thin – think your upper arm.  What an amazing adaptation!


The second conundrum was two-fold.  I found a molar that just did not come from this animal – way too big, and structurally different.  Add to this the fur that made up the pellet: there was not only the dense dark fur of the mole, but also some long pale fur that in no way ever came from a mole.  This fur was too long for any other small mammal (plus the tooth was too big).  I thought at first rabbit, but, again, the tooth morphology was all wrong.  This morning the three of us in the office sat down to wrack our brains to come up with an answer as to what else this owl had eaten. 

“What about opossum,” Greg said. 

OF COURSE!  The answer was so obvious!  That fur could be nothing BUT opossum.  I quickly looked up the dentition and am fairly confident that the molar is a ‘possum molar.  But why there is just the one bone/tooth from the ‘possum will remain a mystery.

Here is what I surmise happened:  the owl caught a mole and had a lovely meal of it, and then later washed it down with an opossum chaser.  While eating the ‘possum it ingested some of the fur, no doubt while plucking the flesh for swallowing.  There was no reason to ingest the bones – meat of the animal was likely plentiful and easy to get at. 

What a wonderful find this owl pellet was - thank you, Mike!!!

May YOUR days be filled with such treasures as this.

Mysteries Abound

Studying nature, the answers we find lead often to more questions. Mysteries abound, such that naturalists and ecologists frequently act as sleuths in pursuit of clues. Observations feed our curiosity, leading to speculation, reflection, and inquiry.

So I was naturally curious when one of our canoe-program volunteers mentioned that he had seen some unusual markings along the bank of the Kishwaukee River in the Deer Run Forest Preserve. He said it looked like someone had dragged something out of the brush and into the river. When he told me about it, he was helping out with our youth canoe camp, Blazing Paddles. We were going to be paddling that very section of the river and he wanted to know if I could help interpret what had made the marks.

As good fortune would have it, he was able to point out the place along the bank shortly before we directed our pod of teenaged paddlers to pull ashore for a lunch break.

  striations, etched like scratch marks into the sloping riverbank

striations, etched like scratch marks into the sloping riverbank

With a small band of curious campers in tow, I hiked back along the shore to investigate. The markings fanned out from a small opening in the vegetation, as if someone had combed or raked the surface. But this was no Zen garden and there were no trails near this section of shoreline. I ducked into the willows to investigate further.

There, behind the edge of the brush line, the answer was apparent. Sharp stumps of willow, a couple of inches in diameter, bore the grooved channels formed by sharp rodent teeth. Beavers apparently had been taking down willows and dragging them toward the water, stump-first with the upper leaves and branches trailing, raking the surface of the soil.

The adolescent paddlers in my company were impressed, never before having seen for themselves that sort of evidence of beaver activity—and they also were impressed with the beavers’ famed industriousness. We knew that the work must have been recent, as we found additional evidence farther along the bank:  A length of willow trunk, gnawed at the base and bearing the tell-tale tooth marks, still had a few green leaves at the tip. Those leaves would have wilted within days of the stem having been severed.

  evidence of beaver activity; adolescent human for scale

evidence of beaver activity; adolescent human for scale

Beavers (Castor canadensis) are the largest rodents in North America, with bodies reaching 30 inches or more in length. A typical adult beaver may weigh between 35 and 65 pounds, although specimens weighing up to 85 pounds have been reported. Beaver teeth are formidable: the front incisors are oversized and appear orange in color, as iron replaces calcium in the enamel, making the incisors exceptionally strong—capable of gnawing through hardwood trees.

  a stump exhibiting the grooved marks left by a beaver’s tough incisors

a stump exhibiting the grooved marks left by a beaver’s tough incisors

Further adaptations of these aquatic mammals include webbing between the toes of the hind feet and the distinctive paddle-like tails. When startled, a beaver may slap its flat tail in warning as it disappears beneath the water’s surface. Beaver fur was prized by the trappers who were among the first Europeans to explore this area. The outer guard hairs are long and glossy while the underfur is very fine and dense, protecting and insulating beavers’ skin from the water. Oils secreted through glands are distributed and combed through the fur while grooming to enhance the waterproof qualities of the fur. Such musky oils are also used to mark territorial boundaries.

  Physiological adaptations like webbed feet and a flat tail enable beavers to thrive in aquatic environments.

Physiological adaptations like webbed feet and a flat tail enable beavers to thrive in aquatic environments.

Beavers are monogamous and live in extended family units, typically spanning three generations. Their preferred diet consists of herbaceous vegetation, although they will browse on woody stems when necessary.

Of course, we seldom see beavers. Not only are they generally restricted to riparian and pond-side habitats, they also are generally nocturnal, spending the daylight hours in lodges built of branches and accessible through underwater entrances. So, like much of the wildlife with whom we share this little corner of the planet, they may remain unseen, but can be known by their effects.

And beavers can have amazing effects on the environment. They are nature’s environmental engineers; their dams and lodges my redirect the flow of streams and rivers, flooding vast areas and influencing plant communities and habitats over long periods of time.

Nature is endlessly fascinating; collecting evidence, we are drawn deeper into explorations of interrelated phenomenon. Threads lead to nodes that branch off to other threads. One of the things that I find satisfying about studying nature is that we can devote a lifetime of study there and never get to the end of it all. Mysteries abound and there is always more to explore.

Home Sweet Home

Home. Such a simple, yet evocative word. So essential to our sense of security and wellbeing. Most of us rely pretty heavily on the comforts of home to help us endure the vicissitudes of life out there in the wide world. Faced with daunting challenges and fearful prospects, dangers, difficulties and dilemmas, the child within cries, “I wanna go home!”

We are not alone in finding safety and comfort in the nest, in the den, in the burrow. Our animal compatriots in the wild need their space also. Educators here at Severson Dells explain to school groups that organisms “Have to Have a Habitat” and we explore the many ways in which they find their respective niches in nature. Every organism needs shelter, nourishment (food and water), and space. If any of those needs is withheld, the organism cannot thrive and may not survive—at least not for long.

I was reminded of these essential truths recently when setting up a photographic plot to record progress in restoration here at The Dells. Along the crest of a low ridge, I came across a spoil pile:  light-brown glacial till unearthed from below the surface by an animal digging a burrow or den. Evidently, the animal had taken up residence there some time ago:  the soil was worn and lightly weathered; new plants had taken root there.

  Outside this burrow, the spoil pile has been colonized by new plants.

Outside this burrow, the spoil pile has been colonized by new plants.

Just a few feet away, however, was a second excavation, one that apparently was quite fresh, looking as if it had never seen rain. What impressed me about it was the size of the stones that had been dragged or pushed out of the hole. Some were rough-hewn, several inches in diameter, and must have weighed a few pounds.

  a new spoil pile of glacial till featuring large stones unearthed from below

a new spoil pile of glacial till featuring large stones unearthed from below

It can be difficult to tell with certainty which local mammal would have dug a given burrow. For denning season, coyotes may dig holes to occupy while giving birth and caring for their young pups, although such dens are generally abandoned by early July. Opportunistic as they are, coyotes are more likely to use a den that was excavated, and subsequently abandoned, by another animal. Red foxes typically leave scraps of bone and hide around a den entrance. Woodchucks (groundhogs) are well known for their excavation expertise and their dens often feature a “dirt porch.” A woodchuck would be capable of pushing a fairly large stone up and out of its burrow.

Curiously, a number of local animals may occupy a single burrow, either consecutively or—reportedly—even at once. Skunks, opossums, badgers, coyotes, raccoons, and groundhogs are said to be among those known to cohabitate from time to time.

Hollow trees, of course, offer another familiar form of shelter for wildlife. A large oak near the underground burrows presented an ample opening into an interior chamber; a walnut husk on the lip of the opening hinted at the chamber’s occupancy.

  another residential address for local wildlife

another residential address for local wildlife

In addition to the many bird species known to be cavity nesters, the following mammal species also are known to occupy hollow trees:  raccoons, opossums, fox squirrels, gray squirrels, flying squirrels, bats, white-footed mice, bobcats, and gray foxes. (Yes, gray foxes do climb trees!) Given the walnut husk, it seems likely that one of the squirrels calls this place home.

Home. It means much more than the house (or den or burrow or nest) that we live in. Home embraces the wider environment. Our community. And when we care deeply about the natural environment, we come to realize and respect the fact that our home includes at least a portion of the natural world. And we associate our sense of comfort and wellbeing with that local environment. This is what it means to have developed a sense of place. And this is what it means to come home to nature.

Forest Fantasy Camp

I know what you are thinking:  what can magic and dragons and potions have to do with environmental education?  Believe it or not, many of the classes that JK Rowling came up with for students to take while attending Hogwarts School of Witchcraft and Wizardry are a perfect fit for teaching kids about the outdoors.  Herbology?  That's botany!  Potions?  How about making stuff with the plants you learned about in Herbology?  Care of Magical Creatures?  That translates into learning about any of the many species of animals that live around here (and perhaps inventing a few additional ones just to add a spark of imagination).  Defense Against the Dark Arts?  How about learning how to become invisible?

Check out what we did:

Monday.  Campers were sorted into their Houses: Pyrewyrm, Wulfrun or Eagleloft.   Afterwards they made their wands.

 Each House could earn points by answering questions correctly and doing good deeds.  Points were lost when campers didn't follow rules.

Each House could earn points by answering questions correctly and doing good deeds.  Points were lost when campers didn't follow rules.

 Campers enjoyed decorating their wands and wanted to bring them everywhere.

Campers enjoyed decorating their wands and wanted to bring them everywhere.

Our first full class was Herbology, and we learned about some of the plants that grow here that have healing properties, like jewelweed and plantain.  After lunch, it was time for Potions, and we made a healing salve with plantain that we harvested right here.

 Healing Salve:  Healer's Friend (plantain) simmering in Bog Juice (olive oil).  Will be strained and the liquid will have Golden Wax (bees wax) added to produce a salve.  Each camper received a small jar of salve.

Healing Salve:  Healer's Friend (plantain) simmering in Bog Juice (olive oil).  Will be strained and the liquid will have Golden Wax (bees wax) added to produce a salve.  Each camper received a small jar of salve.

Tuesday.  We were supposed to study aquatic creatures in Care of Magical Creatures (with Professor Cora Animacules), but the stream was still a bit too high, and most campers were not prepared to go in.   

 Looking for critters...watching out for Grindylows.

Looking for critters...watching out for Grindylows.

 It was slim pickings, but we did find a crusty toe-grabber (crayfish).

It was slim pickings, but we did find a crusty toe-grabber (crayfish).

After lunch, we had an Astronomy lesson and learned about a few of the constellations that are associated with the Harry Potter books, as well as learning which ones campers would be likely to see even if they live in the city.  Everyone made a star wheel to take home.

Wednesday.  We were back in Herbology this morning, and Professor Albus Quercus taught the campers about some of the dangerous and/or interesting plants that live here (Tentacula/poison ivy; Devil's Sting/wood nettle; Mandrake/mayapple).  Campers recorded them in their spellbooks.


Then it was time for Potions again, and this time we made Enemy Repellent, with Manticore Milk (glue), Goblin Slobber (starch) and Goblin Blood (food coloring).  Three drops on the trail behind you will keep your enemies from following you.


We spent some time in The Grove...


...and ended the day making Bowtruckles (guardians of wand trees, according to JKR) to take home.


Thursday.  Care of Magical Creatures was first on the docket this morning.  We learned about some woodland creatures and built a few fairy homes.


After "summoning" a Fire Snake on the screened-in porch (baking soda, powdered sugar, alcohol and sand), we had lunch and then spent the afternoon in Defense Against the Dark Arts class with Professor Danielle Spinifera, where we leared about invisibility.  And what is better to teach invisibility than camouflage in the mud?!

 At first we tried just adding water to some mud left behind by recent rains.

At first we tried just adding water to some mud left behind by recent rains.

 But then Prof. Spinifera took the campers down to the stream where we found the mother load of mud.

But then Prof. Spinifera took the campers down to the stream where we found the mother load of mud.

 Once we were good and muddy, it was time to add some vegetation...

Once we were good and muddy, it was time to add some vegetation...

 ...and then see if the campers could disappear in the woods.  It worked pretty well.

...and then see if the campers could disappear in the woods.  It worked pretty well.

Friday.  Our day began with a Dragon Egg Hunt.  A dragon came through the forest during the night and had laid her eggs along the path.  We searched for them and then helped the baby dragons hatch.

 This egg had a Forest Spirit guarding it.  It later proved to have twins in it!

This egg had a Forest Spirit guarding it.  It later proved to have twins in it!

 We helped the hatchlings emerge.

We helped the hatchlings emerge.

 Everyone with his or her hatchling.

Everyone with his or her hatchling.

That afternoon Professor Quercus did an Augury and Aeromancy lesson.  Campers learned how people throughout history used birds and bird behavior to predict events (augury), and then how to read the clouds to know what kind of weather is on the way. 

 Looking at the lone cloud in the sky to figure out what the upcoming weather might be.

Looking at the lone cloud in the sky to figure out what the upcoming weather might be.

Next we took our O.W.L.s - tests to see how much we learned this week.  Everyone passed!  

It was then time to award the House Cup.  Wulfrun House had the most points and won the cup for this inaugural year of Forest Fantasy Camp.  Everyone also got a Pygmy Puff to take home.

 Members of Wulfrun House, with their Head of House, Prof. Cora Animacules.

Members of Wulfrun House, with their Head of House, Prof. Cora Animacules.

 Eagleloft House, with their Head of House, Prof. Albus Quercus.

Eagleloft House, with their Head of House, Prof. Albus Quercus.

 Pyrewyrm House, with their Head of House, Prof. Danielle Spinifera.

Pyrewyrm House, with their Head of House, Prof. Danielle Spinifera.

The afternoon was slated to be another scorcher, so we were ready with our Water Olympics!  It was a great way to wrap up a fun and adventurous camp.


Will we be offering this camp again next year?  I'm thinking YES!

Most sincerely yours, Headmistress Eleanor Plunkett


 Every year in June I enter into a fresh round of negotiations. No, it’s not an annual contract; I am just trying to come to terms with some of my avian colleagues. You see, it is in June that the ripening fruits of serviceberry shrubs turn dusky purple and invite us to partake of the berries, luscious and delicious.

In fact, Juneberry is another common name for serviceberry, as is shadblow.

Robins are among the first birds called to raid my trees; Cedar Waxwings follow soon after. I have two serviceberry trees (shrubs) at my house and in most years they offer up an ample harvest; there’s plenty to share with my avian neighbors. The trouble is that the trees have grown tall enough that I can only reach the lower tiers of fruit, so only a portion of the produce can be harvested by me while the Robins and Waxwings have access to all.

 Ripening Juneberries attract birds (and people).

Ripening Juneberries attract birds (and people).

Serviceberries (Juneberries, shadblow) are woody shrubs or small trees in the genus Amelanchier. There are about 20 species that occur in North America. Authors Gerould Wilhelm and Laura Rericha describe eight species and one hybrid in their 2017 tome, Flora of the Chicago Region. Of the eight species listed, six are presumed to be native to the region. (Neither the nonnative species nor the hybrid cultivar are considered to be invasive here.)

Four serviceberry species have been recorded from Forest Preserves of Winnebago County:  eastern Juneberry (Amelanchier arborea) is listed from Rockford Rotary Forest Preserve; low Juneberry (A. humilis) can be found at Blackhawk Springs and Seward Bluffs; inland serviceberry (A. interior) has been reported from Colored Sands, Sugar River, and Sugar River Alder; Allegheny serviceberry (A. laevis) is at Blackhawk Springs, Kishwaukee Gorge, Severson Dells, and Seward Bluffs.

For a variety of good reasons, serviceberries have become popular landscape plants in both commercial and residential settings. Their bark, smooth and gray, with spiraling dark streaks, offers distinctive winter interest. The leaves are small, oval, and with lightly toothed margins. In April and May, these members of the rose family (Rosaceae) are bedecked in flowers, each bearing five white, strap-like petals, longer than they are wide. The flowers yield abundant fruits, edible berries (actually pomes, fleshy fruits that form from an inferior ovary, i.e., below the other flower parts) that ripen in June. The fall foliage turns richly to tones of apricot and orange with hints of red. Some serviceberries tend toward a tree-like growth form, but attaining a height of only about 25 feet; others, especially those sold in the landscape or nursery trade, are predisposed toward expression as multi-trunked shrubs. Serviceberries are the larval host of Red-spotted Purple butterflies.

  Amelanchier  in autumn splendor

Amelanchier in autumn splendor

The common name of shadblow (or shadbush) comes from the eastern region of the country, where the blooming of shadblow was said to coincide with the running of the shad to spawn in New England rivers. The name serviceberry is said to have derived from the resumption of certain “services” in the spring, whether the performance of marriage ceremonies (wedding services) or the ability to dig graves in newly thawed ground (burial services). Juneberry, of course, refers to the ripening fruit, the cause of my conversing with birds.

My negotiations with the foraging birds goes something like this. I’ll go out to my serviceberries with a small basket to collect the fruit, flushing a few birds out of the trees. The Cedar Waxwings may quickly disperse to regroup out of sight; the Robins squawk in protest as they fly off to the nearby crabapples or perch on the edge of the gutter and eye me with suspicion.

If I approach slowly and quietly, the Waxwings may linger so that I might reason with them. I explain that they are welcome to all the berries at the top of shrubs, while those situated within my reach are reserved for me. The Waxwings are generally agreeable to these terms and seem to show admirable restraint.

The Robins, however, laugh at me. They dismiss me with derision, as if to say, “Hah! What are you going to do about it?” Once I am back inside the house, the Robins are back in the lower branches.

I suppose there’s nothing for it but to plant more serviceberries.


Of all the eagerly anticipated phenomena that mark the spiraling dance of the seasons, few are as sweet, or received with such delight, as the appearance of lightning bugs in June.

Perhaps you call them fireflies. I grew up calling them lightning bugs. In fact, they are neither flies nor bugs. They are winged beetles, in the order Coleoptera. And for many of us who grew up the Midwest, these seemingly magical insects provided an early-childhood introduction to the joyful exploration of the natural world. Many of us have fond memories of dashing across the lawn, big glass jar in hand, chasing flickering points of light and squealing with anticipation of the capture. And we always knew that we could catch these harmless little insects in our bare hands, examine them closely—in rapt fascination of their eerie rhythmic glow—keep them for a time in our clear glass jars (breathing holes punched in the metal lids), and release them once more into their habitat before we were tucked into bed.

  Random Factoid:  A Jamaican term for lightning bug is, “blinkie.”

Random Factoid:  A Jamaican term for lightning bug is, “blinkie.”

Adaptation in nature is nothing less than amazing. Why would a little insect evolve in such a way as to regularly emit such a bright, distinctive glow? The short answer is that they use the light to communicate. And most of that communication is about finding a suitable mate.

There are thousands of species of lightning bugs (or fireflies—I’ll use the terms interchangeably) spread across temperate and tropical areas of the globe, classified within five subfamilies. While there are more than 200 species in North America, curiously enough there are few species that occur west of Kansas. (If you really want to impress your friends visiting here from out west, take them to a firefly show.)

Firefly behavior, color, and habitat preferences vary by species, but in general their bioluminescence is caused by enzyme-induced chemical reactions within specialized cells called photocytes. Reflector cells may intensify and direct the light emitted by the photocytes. Light cast by a firefly is extraordinarily efficient; it is what we call a “cold light” because, unlike most sources of illumination, there is no energy lost as heat.

While some fireflies may emit light to defend their territory or deter predators, what we typically see is a courtship display. Each species presents a distinctive blinking pattern that is unique to that species (although there are a few species that mimic one another as a means of interspecies trickery). Males flash their rhythmic signals in flight while females perch in low vegetation; a female may reflect the male’s flash pattern or she may, at a precise time interval, blink back to the male, signaling her whereabouts; the flashing and blinking typically continue until mating is complete.

The female lays her eggs under the surface of the soil. After about three weeks, the eggs hatch, revealing larvae that are fascinating in appearance:  segmented and armored, looking perhaps like a trilobite or some kind of spiny pillbug. The larvae persist in that form for a year or two before spending about three weeks as pupae, emerging as adults who then live for only 3 or 4 weeks—just long enough to reproduce.

  A lightning bug larva is a fearsome sight—at least to its prey.

A lightning bug larva is a fearsome sight—at least to its prey.

It is pleasing to find a field or woodland edge filled with the silent twilight courtship display of fireflies. Even as adults we can be mesmerized by the flashing, dancing patterns of green or yellow points of light, swimming in the mild evening air. And yet, some neighborhoods—even some natural areas—seem to host fewer lightning bugs today than in years past. I haven’t found any published studies that compare population trends over time, but there are anecdotal reports of diminishing numbers.

Most of a firefly’s life is spent in larval form, on or below the surface of the soil where they are susceptible to environmental dangers such as drought, flood, contaminants, and predation. Some of the threats to lightning bugs are decidedly human in origin. Lawn chemicals are especially troublesome:  some can kill firefly larvae outright, and they might also kill the organisms that the larvae need to eat. Artificial lighting can reduce the ability of adult males and females to find each other, so we are encouraged to shut off our lights whenever they are not needed.

Those of us who grew up in suburban neighborhoods here in the Midwest may associate lightning bugs with lawns and the residential landscape, but of course those little beetles were here long before modern humans changed the environment, so what natural habitats would have been their haunts? Reportedly, they prefer moist environments that support low-stature vegetation. I would suppose that sedge meadows, mesic savannas, and the margins of wet prairies would have been their preferred habitats.

The ideal time to witness the firefly display is right around dusk, a little after sunset, at the onset of darkness. Firefly activity diminishes considerably about an hour or two after sunset.

Take my advice. Find a moist prairie, sedge meadow edge, or untreated old field. (If you live in a neighborhood that still has abundant lightning bugs, you can do this at home, although ambient light from the neighbors can interfere with the experience.) Perch yourself comfortably at sundown, and take in the show. Allow a soft focus to guide your steady gaze across the gloaming space in front of you. Turn off your thoughts for a few moments, quieting the internal dialog; with silent mind and open eyes, witness the play at hand… and smile like a child enchanted.

Get Outside

 Heed, for example, the siren song of the Kishwaukee River, enticing you to Get Outside, Get Healthy.

Heed, for example, the siren song of the Kishwaukee River, enticing you to Get Outside, Get Healthy.

How much time do you spend outdoors? Is it enough? How much time should we spend outdoors?? Would spending more time outdoors improve your health?!

You’ve probably seen statistics that suggest that Americans today spend 90 percent of their time indoors or otherwise in artificial environments (like driving a car). On the one hand, that number strikes me as appalling; on the other hand, it shouldn’t surprise me. After all, most folks are employed in indoor work and live in houses or apartments, driving door-to-door between work, home, and indoor errands.

I prefer natural, outdoor environments:  I thrive outside.

Of course, I am fortunate to be able to work in a field that places me in nature on a routine basis. I celebrate the open sky above, the panoramic vistas of wide prairies, the rich scent of wetlands, and the sheltering closeness of the shady forest. To feel the breeze, and gulp fresh air; to delight equally in snowfall, sunshine, starlight and rain—these are experiences that can feed the spirit and help sustain an appreciation of the awesome beauty of living on earth.

And yes, those disturbing statistics are out there. Most recently, on May 19, the New York Post published a story that reported the findings of an inquiry conducted by Velux, a global architectural firm. The survey, which sampled some 16,000 respondents in 14 countries, found that Canadians, Americans, and Brits were among the folks most likely to stay indoors (around 25 percent of the population spending 20-to-24 hours per day indoors). Italians and Czechs occupied the other end of the spectrum, with 57 percent of respondents spending fewer than 14 hours per day indoors.

The famous “90 percent of time spent indoors” statistic appears to derive from a more rigorous study, The National Human Activity Pattern Survey (NHAPS): A Resource for Assessing Exposure to Environmental Pollutants (Klepeis et al., 2001, Lawrence Berkeley National Laboratory). Results of the study suggest that, on average, Americans spend 87 percent of their time indoors, plus an additional six percent of their time in an enclosed vehicle. The survey was funded by U.S. EPA and (presumably) like the Velux study was intended to quantify the degree of exposure to indoor pollutants.

Such surveys may focus on the indoor environment because the researchers were looking to justify efforts to address indoor air quality and other (indoor) environmental exposures. The implication (stated, in fact, by one of the authors) is that human beings have become “an indoor species.”

Yet this is a relatively recent development in human history. A few (human) generations ago, most people spent a good deal more time outdoors. And some of the respiratory ailments that are so common today were less prevalent. And how about all those allergies that folks are facing today?

Human health and wellness may be enhanced by spending more time outdoors—especially given the fact that most outdoor time includes a higher degree of exercise than most indoor time. A number of studies published during the past ten years document the benefits of spending time in nature. Exposure to natural environments has a positive correlation to enhanced wellbeing, and with greater exposure to nature, there is a greater positive effect. I find it noteworthy that this is not so much about healing illness as it is improving wellness and being less likely to fall ill in the first place.

Severson Dells Nature Center is working with the Forest Preserves of Winnebago County to promote such wellbeing. Just this past week, on May 19, we launched the 2018 Get Outside, Get Healthy campaign, a series of events—free to the public—that support wellness through outdoor experience. Many of these events will take place at Severson Dells, listed on the calendar of events here on this website. Additional details are available through the Forest Preserves’ website.

So please, get out of the house, get out of your car:  Get Outside and Get Healthy!

Mantis Musings

It is spring, and any given week from mid-April to late May we may have 200+ students visiting for various outdoor/nature programs.  I love turning them loose to see what they can find, and given the opportunity, they make many amazing discoveries.  

Recently, we had a group participating in our Biodiversity Investigation program, which has them walking through two different habitats (woods and prairie), looking for (and recording) signs of wildlife.  Often, this means insects, although sometimes we find birds, animal tracks, dens and nests as well.  Under the bark of decaying trees, or in the wood of rotting logs, are some of the best places to explore.  The grassland is a little more of a challenge right now, because it hasn't been quite warm enough for the critters to be out and about.  Never the less, our group had a great find:  not one, but TWO praying mantis egg cases.

 Egg case of the Chinese Praying Mantis.

Egg case of the Chinese Praying Mantis.

These are great finds because a) they are so odd-looking, and b) they are not something most people encounter.  We left the first one out in the field, but the second one I brought back in to the office to see if we could get it to hatch indoors and share with visitors.

Thanks to a post that came through on my Facebook feed this week about how we should destroy any eggs cases we find like this, for they are from the non-native Chinese praying mantis, which is apparently some consider an invasive species, I decided to do a little research. 

While there are about 2000 species of mantises/mantids found worldwide, North America is home to about 21.  Of those, only one is found in our neck of the woods:  the Carolina Mantis (Stagmomantus carolina).  Two non-native species are found here, too, and in much greater numbers:  the Chinese Mantis (Tenodera aridfolia sinensis) and the European Mantis (Mantis religiosa).  Both have been here over 100 years and are considered "naturalized."  

Last summer we had a beautiful enormous specimen clinging to the porch screen for a couple days right outside our entry way.  Simply because I knew that the Chinese mantis was quite common, I presumed that was who she was (pretty sure it was a female, too, because her abdomen was very large), but yesterday I started wondering:  would I know our native mantis if I saw one?

As it turns out, telling our native mantis from the interlopers is pretty easy, primarily because it is so small by comparison.  S. carolina is about two inches long (compared to the whopping four to six inches of the Chinese; the European falls in between, but on the larger side).  Its wings only cover about 2/3 of its abdomen (100% coverage for the other two), and its colors are mottled, either in browns or greens (the others are more solidly brown or green).  Our native mantis exhibits no spots between its two predatory front legs; the Chinese has a yellow spot, while the European sports black or black and white bullseye spots.

 Found this good ID/comparison photo online - thanks to John Meyer of NC State University.

Found this good ID/comparison photo online - thanks to John Meyer of NC State University.

If you find a hard, frothy-looking egg case (ootheca), you can tell if it is native or not by the size and shape.  Our native mantids' egg cases are small, and are longer than they are wide.  The Chinese mantis egg case is fairly stout, almost round - as seen in photo above.  The European mantis egg case falls in between - longer than wide, but not as narrow as the native ootheca.

 Native Carolina praying mantis egg case - thanks to S. Carolina Public Radio.

Native Carolina praying mantis egg case - thanks to S. Carolina Public Radio.

So this brings us to a conundrum:  are the non-native mantids good or bad?  It depends on who you talk to.  Gardeners love them, because they are providing a beneficial service by eating many insect pests.  However, the fact that our native species is becoming so difficult to find suggests that perhaps they are being elbowed out of the picture by the non-native species. 

Additionally, the Chinese mantis is known to voraciously eat whatever it can catch, including butterflies, beneficial pollinators, tree frogs and even hummingbirds!  Is it also eating our native mantids?  Sounds to me like that is quite possible.

The debate is raging on the Facebook post (it came through my feed again last night), so I sent an email to APHIS to get the official status.  (I've been waiting two weeks for an answer...none received to date.)

So we are left with a quandry:  do we keep the egg case we found on display for visitors, or do we destroy it?  It's a difficult choice to make.

The Quickening

In the middle of April, between snowfalls, with the new leaves of this year’s early wildflowers just starting to unfold, I posted on social media a couple of plant photos (newly emerging leaves) with the following commentary:  “Hang on, kids, here it comes: the quickening exultation of floristic fever as our local vegetation awakens from the deep sleep of winter and races into full form to dazzle and enchant plant geeks across the land.”

I call it the quickening, a term also used to describe the first movements of an unborn child felt by an expectant mother. I use it to describe the first movements we perceive on the part of growing plants each spring, the exceptional acceleration of botanical activity that takes place here April-to-May, that frenzied state of hastening changes, barreling headlong into the growing season as wildflowers and trees alike press forward in an eruption of fecundity that takes our collective breath away. Blink and you’ll miss it.

Every day brings new leaves, new blooms, new discoveries along the trail. Before the trees put forth their leaves, wildflowers—we call them spring ephemerals for the fleeting nature of their appearance—bloom in profusion across our timbered lands. Generally speaking, prairies and wetlands bloom later; springtime is time for the woods to shine.

 Bloodroot (Sanguinaria canadensis) flowers may persist for only a few days.  Photo from Severson Dells, April 24, 2018.

Bloodroot (Sanguinaria canadensis) flowers may persist for only a few days.  Photo from Severson Dells, April 24, 2018.

Spring ephemerals appear in the woods early in the season, before the trees put forth their leaves. Around here, a few weeks after the vernal equinox, sunlight reaches the surface of the earth at a fairly direct angle, fueling the process of photosynthesis in woodland wildflowers. Once the trees come into leaf, shade is more prevalent in the woods and spring ephemerals scale back their metabolic activity; some go dormant by midsummer.

Food produced by these wildflowers during the brief period of active spring growth may be stored underground in a root organ called a corm. Unlike a bulb, which is layered (like an onion), a corm is a solid storage device. It holds enough food for the plant to survive the lengthy period of dormancy, summer to spring, and feed the plant’s growth until it can refuel, so to speak, by conducting photosynthesis.

 Sharp-lobed hepatica (Anemone acutiloba) is a delicate flower of wooded slopes.  Photo from Severson Dells April 24, 2018.

Sharp-lobed hepatica (Anemone acutiloba) is a delicate flower of wooded slopes.  Photo from Severson Dells April 24, 2018.

Woodland wildflowers are among the native plants most favored in this region, arriving as they do to grace the land with color and vitality after the long sleep of dull dormancy. We love our spring ephemerals not only for their sudden beauty, delicate and subtle, but also for their role as harbingers, heralding the commencement of the growing season, with all its promise of delights and discoveries to come.

Our early blooms signal the release of winter’s hold upon the land, offering cheerful relief from the cold and dark months that came before. And these first flowers of the year entice us to explore our natural areas, seeking out each successive species as it expresses itself in the environment, taking its place in a grand botanical pageant that spans the seasons. It starts with the quickening; don’t blink, or you’ll miss it.

Springtail Speculations

Prior to living in Illinois, my only relationship with the insects known as springtails was from their late winter/early spring appearance on top of snow, where for all the world it looked like someone had tripped while carrying a container of ground pepper, dumping its contents all over the white expanse.  Upon close observation, each little flake of pepper takes its turn popping up into the air, drawing the attention of even the most casual of observers.  These critters are affectionately known as snowfleas, even though they are not even remotely related to fleas.

 Snowfleas ( Hypogastrura nivicola ), image taken at a tracking workshop at Kawing Crow Awareness Center, Greenfield, NY - March 2, 2010

Snowfleas (Hypogastrura nivicola), image taken at a tracking workshop at Kawing Crow Awareness Center, Greenfield, NY - March 2, 2010

Last spring, while sharing the wonders of aquatic insects with many school children, we discovered that the surface of the pond here at Severson Dells was covered with springtails - thousands of them (sadly, I have no photos).  I was well and truly stunned - I had no idea they would live on water...literally.

This spring, we found them crawling up and down the trunks of trees.  

 Springtails on tree, Severson Dells Nature Center, Rockford, IL - March 30, 2018

Springtails on tree, Severson Dells Nature Center, Rockford, IL - March 30, 2018

Obviously there is more to springtails than I had originally thought.

Some "quick" research online turned up the usual set of brief verbatim snippets, but then I hit the motherload, a whole book (over 300 pages) about nothing but springtails:  Biology of Springtails by Stephen P. Hopkin.  As fascinating as these insects are, however, I wasn't about to read the whole thing (well, I couldn't, because a) the online review I found had more than half the book missing, b) I wasn't going to spend nearly $200 for an e-book, and c) I simply don't have time to read a scientific tome just to write a few paragraphs for a blog).  But I will share with you some of the highlights, because these really are pretty nifty creatures; then YOU can go buy the book and fill in the rest of the story.

So, Springtails -  subclass Collembola.  Springtails are fairly primitive insects, although there seems to be some debate as to whether or not they are truly insects.  Most enotomologists are happy keeping them in the phylum Arthropoda, so I shall as well.  These insects are tiny - most falling somewhere between 1/16 and 1/8 of an inch (don't let the photos above fool you).  When I said they look like little pepper flakes on the snow, that was no exaggeration.

The name springtail comes from the really nifty appendage they have underneath the abdomen.  This forked "thing," called a furca, is folded underneath the insect and held in place until the springtail needs a quick get-away, then *snap!* it is released (think mouse trap), propelling the insect upwards and away from the impending danger.  Some species can fling themselves many times their own body length in a mere fraction of a second.  On the other hand, those species that live deep in the soil and rarely, if ever, venture forth, may have greatly reduced or even non-existent furcas (furcae?).  Being able to fling themselves with the furca is the only way these insects will "fly" - they have no wings, and therefore are grounded.

Actually, as I continued reading about these insects, I discovered that they have been found way up in the air - caught on sticky traps or in nets pulled by airplanes!  It is believed that they make use of the wind to disperse, climbing way up into the tops of trees when conditions are just right, and hitching a ride, much as young spiders are known to do (only sans the spider silk parachutes).

Now, the scientific name, Collembola, is equally fascinating.  It is from the Greek, as so many scientific names are, and it breaks down as glue (colle) and piston (embolon).  This appellation was given to the critters because of a second interesting feature:  the ventral tube.  This tube is apparently important in the animal's fluid balance, but it is also sticky and can help them stay on slippery surfaces.  Additionally, it can help right the insect after it has flung itself away from danger.

Over 6500 species of springtails have been described to date.  Some live on the surface of the ground/trees (epedaphic), while others are active below (euedaphic).  They live in every environment - including Antarctica, on the surface of water, and even deserts (although they are much less common here).  They are very important in the decomposition process and in maintaining soil health.  They are mostly harmless to humans (don't sting, don't bite), although there are some species that feed directly on plants and can be problematic for agricultural interests.  Most, however, feed on fungal hyphae and/or plant detritis.  There are even a few that are carnivores, gnoshing on nematodes, rotifers and even other Collembola!

So, if you are out walking our trails this spring, and you stop to look at the trunk of a tree and see it alive with little pepper flakes crawling up and down, say hello to the springtails!  If you have a hand lens on you, take a look at some of them up close.  See if you can see the furca.  

The world is full of amazing things, most of which we never see.  Take a moment to look - enchantment is everywhere around us.

Spring Snow

We awoke to snow cover on April 9; overnight precipitation left a couple of inches of fresh snow on the ground, blanketing lawns and other vegetation. Areas of pavement that receive the radiant heat of sunlight were mostly free of snow, but paved areas that remain in shade and otherwise protected from the warming rays of April collected two or more inches of fresh powder.

 In our area, it's not entirely uncommon to receive measurable snow after Easter.

In our area, it's not entirely uncommon to receive measurable snow after Easter.

By the time April makes its way to the top of the calendar lots of folks around here are impatient for warmer weather. To them, snow in April feels like an event out of time. But we’re just two weeks into astronomical spring, the vernal equinox having occurred on March 20 this year, so it didn’t strike me as particularly strange to see snow on the ground. I was, however, curious about past patterns of snowfall, so I checked with the National Weather Service (NWS) of the National Oceanic and Atmospheric Administration (NOAA) to obtain some “Late Season Snow Climatology” information.

It is worth noting that when meteorologists use terms like “normal” or “average,” they usually mean a 30-year average. Here in Rockford, for example, the current NWS “normal” is based on records compiled between 1981 and 2010.

According to the NWS, the “normal” last date of the season on which to expect more than an inch of snow is March 20. However, the “normal” last date for a trace of snow is April 11. So the snow we received this week can hardly be seen as highly unusual. Looking back at earlier records, the latest “last measurable snow” in Rockford was May 11 (1966), and that was more than an inch of accumulation.

I was naturally curious about the phenology of the first snows of the season, as well. It turns out that the “normal” first date on which we receive a trace of snow is November 2; to receive more than an inch we typically would have to wait until December 5. I was surprised by the earliest first date of a trace of snow (October 3, 1951) and equally surprised by the latest first date of an inch or more of snow (February 7, 1921).

On the one hand, we could have snow around here any time between early October (as on October 3, 1951) and late May (like May 24, 1925). Yes, that’s 8 out 12 months during which we might see snow. On the other hand, our first trace of snow might not arrive until the latter half of December (which it did on December 19, 1999) and the last trace snowfall might be over in early March (as it was on March 5, 2012).

Climatologists recognize that weather patterns often vary tremendously year-to-year or decade-to-decade. They have to look at long-term patterns to gain an appreciable understanding of climate.

And this is why we collect phenology data for local plants, recording the dates of events like breaking leaf bud in the spring and colored leaves in the fall:  every year is different. And with every season we witness the cycle of events, turning, spinning, spiraling around and through our perception of the natural world.

Hairy Rope...

Our school season has started back up, and between that and our recent volunteer trainings, a couple ID questions have come to the fore.  Perhaps the most important one has been "is that vine poison ivy or Virginia creeper?"  

Now, once upon a time, I wouldn't have batted an eye looking at a vine.  I stuck by my tried and true rhyme:  "Leaflets three, let it be; hairy rope, don't be a dope."  How could anyone mistake poison ivy ever again?  But a few years ago a fellow naturalist pointed out that Virginia creeper can also have a hairy vine.  What?!?  Say it's not so!  But, alas, it is.

What is a naturalist to do?

Knowing that all things can be identified if one just knows the key thing to look for (although, admittedly, it won't always be something one can see in the field), I have set out on a mission to learn how to tell these two plants the winter...when there are no leaves.  

I share with you here and now the fruits of my labor, namely, a close examination of the rootlets that give the vines their hairy appearance.

 Virginia creeper rootlets (photo credit:  Jim Mason, Great Plains Nature Center)

Virginia creeper rootlets (photo credit:  Jim Mason, Great Plains Nature Center)

 Poison ivy rootlets (photo credit:  Jim Mason, Great Plains Nature Center)

Poison ivy rootlets (photo credit:  Jim Mason, Great Plains Nature Center)

So, here we have two photos of hairy vines.  According to my research, two of the key things to look for are the color and thickness of the "hairy" parts.  Poison ivy vines are covered with very thin, "dark" rootlets, which help it grasp the bark of the tree to which it clings.  Virginia creeper has thicker, "lighter" tendrils (not rootlets, apparently), which also cling to the tree.

Now, I know what you are thinking.  This is easy when they are side-by-side, like telling a downy from a hairy woodpecker is easy when the birds are side-by-side.  Until one has developed a trained eye that automatically knows what it is seeing, these differences aren't always so obvious.  What if the tendrils are young and thin?  What if it is a really old poison ivy vine - do the rootlets thicken with age?  And, as we all know, color is not always the best diagnostic tool ("poison ivy has red leaves" - um, yes, except when they are not red at all).

There's one trait, however, that should be the clincher, and that is the little grippy pads on the terminal ends of the VC tendrils:

 Virginia creeper tendrils with pads (photo credit:  John Cardin, OSU,

Virginia creeper tendrils with pads (photo credit:  John Cardin, OSU,

 Close-up of Virginia creeper tendril with pads (photo credit: Dale Hoyt, Nature Rambling blog).

Close-up of Virginia creeper tendril with pads (photo credit: Dale Hoyt, Nature Rambling blog).

Ah-ha!  That must be it!  Those pads certainly seem obvious in these photos, but are they as apparent when one is facing a vine, in the woods, in winter?  Fortunately, this afternoon I had an opportunity to check. 

I'm sorry to say, the pad prognosis was not promising.

 Vine #1:  Thick and light-colored - must be Virginia creeper.  No pads evident, however.

Vine #1:  Thick and light-colored - must be Virginia creeper.  No pads evident, however.


Vine #2:  Those hairs are pretty fine, and certainly darker than those on #1.  I'm going with PI on this one.

 Vine #3:  My hand is in there to show just how robust this vine is - nearly 3" diameter.  It is densely hairy, but those hairs, well, some are rather thick and light-colored, while others are thin and dark.  ACK!  I was afraid this would happen.  Looking up the vine, I could see there are actual branches coming out of it, which, I have been told, is an indication that it is PI:  older vines are known to have branches from several inches to multiple feet in length, and VC won't have branches much longer than 4".  Therefore, this must be PI.

Vine #3:  My hand is in there to show just how robust this vine is - nearly 3" diameter.  It is densely hairy, but those hairs, well, some are rather thick and light-colored, while others are thin and dark.  ACK!  I was afraid this would happen.  Looking up the vine, I could see there are actual branches coming out of it, which, I have been told, is an indication that it is PI:  older vines are known to have branches from several inches to multiple feet in length, and VC won't have branches much longer than 4".  Therefore, this must be PI.

 Vine #4:  Densely covered with thin, dark rootlets - no doubt in my mind this is PI.

Vine #4:  Densely covered with thin, dark rootlets - no doubt in my mind this is PI.

Conclusions:  Pads on Virginia creeper tendrils are not apparent in winter.  I suspect that perhaps they are mostly visible on young/new growth.  Additionally, old, robust PI can have thick rootlets, some of which are light-colored.  

I will be continuing my investigation on the differences between PI and VC vines as the seasons progress, but until further notice, I will stick to the rhyme and avoid touching any hairy vines, regardless of how thick or light the rootlets/tendrils are.

Planet of Fire

Prescribed fire is one of the most important tools available to land managers today. Although much of the 20th century was a period of fire suppression, the deliberate ignition of dry vegetation has been taking place across our local landscapes for thousands of years. Long before there were ecologists to carry the flame, indigenous people lit the landscape on a regular basis. Ever since the last glaciers retreated from the area, our plant communities evolved in the presence of periodic fire. Most of the plant communities that occur in our region are considered to be fire-dependent communities, that is, they replicate themselves and exhibit stability over time as long as landscape fire is part of the ecological equation; in the absence of fire, these communities change into something else—usually they degrade.

 Prescribed fire rejuvenates a prairie.

Prescribed fire rejuvenates a prairie.

So, among the techniques employed in ecological restoration, the application of prescribed fire restores a natural process previously withheld from the land. Stephen J. Pyne of Arizona State University has written widely on the subject of fire (relative to ecology), and while ecologists often characterize fire as a disturbance (like an ice storm or a bison wallow), Pyne asserts, “It makes more sense to imagine fire as a catalyst.”

Pyne sees fire as a contextual reaction, taking its character from its fuel and environment. Fine-textured fuels—like dry grasses—flash and burn fast, while coarse fuels—like fallen trees—require higher levels of heat for ignition and burn more slowly. A wind-driven prairie fire will race up a dry hill, while a slow, low woodland fire will creep through leaf litter, leaving unburned fuel in its wake. In any case, landscape fire feeds upon (consumes) plant matter. And fires have burned across the earth ever since there have been plants that dry out to serve as a flammable fuel source. Pyne has referred to the earth as a planet of fire.

 Prescribed fire in a woodland is characterized by low flames and leaves a patchy mosaic of burned areas.

Prescribed fire in a woodland is characterized by low flames and leaves a patchy mosaic of burned areas.

Fire is one of the elements responsible for humans’ rise to keystone species status. No species other than humans wields fire; no other ecological force shapes the landscape the way fire can. To quote a recent report from the U.S. Fish & Wildlife Service (USFWS):  “There is no ecological equivalent to fire. No other type of natural or man-made action yields the same benefits.”

The benefits of fire, naturally, vary according to the ecosystem or ecoregion affected. Locally, fire removes dead plant material (duff) and supports the rapid growth of plants in spring, the bare soil blackened by fire readily accepting the warming rays of the sun. The fresh green shoots may attract grazers, which may attract predators, thus fueling the nutrient cycle across trophic levels in the ecosystem. Fire hastens the recycling of nutrients back into the soil. Fire kills or injures individual woody plants, with seedlings and saplings among the most susceptible (mature trees, especially our fire-adapted species such as oaks being far less likely to be harmed). Although there are exceptions, and depending upon the timing of the burn, prescribed fire tends to favor the establishment of native plants, selectively deterring invasive species. Burning reduces the buildup of fuels and lessens the likelihood and severity of wildfire.

Since 2003, USFWS has been employing prescribed fire in the management of their lands. At Necedah National Wildlife Refuge in central Wisconsin, habitat improvements ascribed to prescribed fire have resulted in dramatic increases in the local population of Red-headed Woodpeckers, a signature species of Midwestern oak savannas. According to USFWS, “Oak savannas survive and flourish only with the help of occasional grass fires.” Such fires throughout the Midwest favor native warm-season grasses at the expense of nonnative cool-season grasses.

So in the early spring—and again in the fall—you may see smoke on the horizon, lifting toward the heavens; you may visit your favorite natural areas to find them briefly blackened below your feet. Know that it is a good thing. After all, it’s only natural: we live on a planet of fire.

Surprise Roommates

I recently had one of my doors replaced at home.  It was quite the operation as they ripped off the indoor trim, then pulled out screws and loosened the old door and its frame before wrestling the new one in place.  When the frame was gone, the naked beams inside between the walls and siding were exposed, and there, crawling about on the wood, were now-active clusters of (Asian) ladybugs (which just proved to me how much space there was around the old door, in case the cold air blowing in around it wasn’t enough proof).

 Bat that the cats found in my farmhouse in Michigan.  

Bat that the cats found in my farmhouse in Michigan.  

Isn’t it amazing how critters can get into our houses through the smallest of cracks?  Ladybugs, box elder bugs, spiders, ants, mice, bats, snakes, shrews, flies, wasps, chipmunks, squirrels, raccoons…I’ve had them all over the years, and no doubt you have, too.  Now, obviously, if one has raccoons and squirrels getting in, one must have some significant gaps somewhere, but some of these animals really don’t need a lot of room.  Take a bat, for example.  A little brown bat only needs a quarter-inch gap to crawl through.  A quarter inch!  If you’ve ever watched a cat squish itself under a dresser, then maybe this isn’t too impressive, for little browns are not terribly big to begin with.  But even so, a quarter inch is pretty darn small.

Some critters, like carpenter ants and termites, and yes, even the red squirrels, chew their way in.  Not too much you can do about that, I guess, but patrol your house and be vigilant.  The rest, however, have got to find the nooks and crannies that result from either poor construction or the house settling and aging over time.

Back east, the worst we had, infestation-wise, was the yearly appearance of cluster flies.  No one in Michigan had ever heard of these – do you get them here in Illinois?  These would show up in late winter/spring – hundreds of flies that would cling to ceilings and windows and just sit there in an apparent stupor.  One would go around with a vacuum cleaner and suck them up, but they are so logy that you could pluck them off with chopsticks if you were so inclined.

It wasn’t until I moved to the Midwest (Michigan and here) that I discovered the joys of box elder bugs.  At my old MI farmhouse, they covered the outer walls and front porch by the hundreds on warm spring days (and lurked on the porch all winter long).  Any visitors we’ve had at Severson Dells since last fall have enjoyed watching the ones that took up residence indoors last October and have yet to leave.  I wonder what they do for food and water all winter.  I did find one swimming in my mug of water when we had a volunteer gathering in our classroom last month, so perhaps they wait for serendipitous sustenance appearances.

I think the oddest creatures I’ve had visit my abode were the snakes and shrews.  Okay – singular snake, but I have had more than one shrew.  Although, now that I think of it, we did have a snake in the ladies’ room toilet here at Severson Dells last fall (it was a very small brown snake, which is harmless, so no one panic).  No idea where it came from or how it got there, but the others I only discovered when my cat(s) brought them to my attention…as gifts…nearly dead.

When it comes to spiders in the house, here is a little tidbit perhaps you didn’t know:  house spiders will not survive if you put them outdoors.  They have evolved with humans over the centuries, so their natural habitat is your home.  Of course, not all spiders in your house are house spiders, and some eight-legged visitors would do just as well outdoors, so learn to identify them and then feel free to evict them.

I find most unexpected household visitors, of the four- to eight-legged variety, have high entertainment value for the cats.  Usually in the middle of the night.  And it’s not like the cats actually do anything about the visitors, other than play with them.  If they removed them from the house for me, that would be worth it, but no, they just chase them around, knocking over knick-knacks, clawing at paintings on the walls, scratching under doors, and staring off into space left…right…left…right…  I sometimes wonder if they are watching ghosts, ‘cause there are times when they are watching things that, as far as I can tell, are just not there.  I could tell you a few stories!

So I guess this just goes to show that we are never alone.  And with warmer days on the way, we are bound to discover a few more roommates that we didn’t know we had.



With the Vernal Equinox nearly upon us (it’s March 20 this year), my imagination turns to the flowering plants. We aren’t seeing much activity yet, of course, but a few specialized species make their move early in the season, taking advantage of the lack of competition as other organisms have yet to awaken from their winter slumber.

One of the earliest—and best-known—spring bloomers is skunk cabbage (Symplocarpus foetidus), a denizen of calcareous seeps, fens, and banks of spring-fed streams. Some authorities assert that, of all our flora, skunk cabbage is the first to bloom each year. To be sure, it has its charms, but as flowers go some folks might be disappointed. It looks and smells—more or less—like a wad of rotting flesh. It is no surprise, then, to find that it is pollinated principally by flesh flies (Sarcophagidae family) and carrion flies (Calliphoridae family), which happen to be out and about early in the year, feeding on carcasses and contributing to the nutrient cycle by aiding in decomposition.

Often overlooked are the flowers of the silver maple (Acer saccharinum). This fast-growing tree has found its way into our residential landscapes as an opportunistic volunteer, but its shallow, spreading root system may lift sidewalks, causing them to buckle, and may enter drain lines and sewer pipes, blocking their capacity. Silver maple’s relatively brittle wood, in combination with its growth form, leaves the trees susceptible to damage from wind, ice, and snow. And while they may not be ideal street trees, silver maples perform essential ecosystem services, playing host to hundreds of species of beneficial insects, as well as providing forage and habitat for many birds and mammals. Their natural habitat is alluvial forests such as those occupying floodplains along our water courses. The flowers are tiny and have no petals, but the stamens, pistils, and floral bracts may present a rich, reddish-pink color. While the flowers may bloom as early as February, they often escape our attention (situated high in the tree) until storms knock them to the ground.

 Florets of silver maple (Acer saccharinum)

Florets of silver maple (Acer saccharinum)

One of my favorite native plants to present its flowers very early in the year is American hazelnut (Corylus americana), which usually enters its bloom period in the middle of March. We have a fine, tall specimen near the Severson Dells Nature Center, so I have been watching it daily in anticipation of seeing its welcome demonstration that spring is arriving.

Hazels bear separate male (staminate) and female (pistillate) flowers on the same plant (what we call a monoecious plant species). The male flowers form during the growing season and remain immature through the winter, visible as catkins, dangling from the twigs of the shrub (and making it relatively easy to identify hazel during the winter). The catkins elongate to about 2 to 3 inches or more as they mature in mid-spring. It is the pistillate flowers that I look for in March. While most of the flower remains hidden within its protective bracts, the slender, magenta stigmas are exposed, filamentous in the vernal air. Hazels, like maples, are wind-pollinated.

 Female (pistillate) flowers of hazelnut (Corylus americana) exert their magenta stigmata (left center) while male (staminate) catkins dangle nearby,

Female (pistillate) flowers of hazelnut (Corylus americana) exert their magenta stigmata (left center) while male (staminate) catkins dangle nearby,

The fruits (hazel nuts) are beautiful brown orbs wrapped in dramatically fringed bracts. In appearance, the nut is similar to that of the European filbert (Corylus avellana), a close relative, but the bracts of the American hazelnut are distinctive. It can be difficult to collect hazel nuts, they are prized by squirrels and other wildlife. And while hazel brush was frequently noted by surveyors who crisscrossed the region during the early nineteenth century, we see relatively few specimens today, mostly due to habitat loss and encroachment from invasive species.

 Hazel nuts encased in their distinctive bracts--at Pecatonica River Forest Preserve

Hazel nuts encased in their distinctive bracts--at Pecatonica River Forest Preserve

So, before those beloved woodland wildflowers even begin to festoon the forest floor with their blooms of white and yellow, look to the trees and shrubs above for some of the first flowers to burst their buds and herald the coming of spring.

Tale of the Thaw, Part 2

Morning mist lifts from fence lines drawn between farm fields draped in melting snow; ghostly shrubs, veiled in frigid fog, lurk behind the glistening vapors of dawn.

Such were the scenes of the second thaw of the month as mild temperatures returned to the area during the latter half of February. The snow and ice that had accumulated over previous weeks quickly melted and flowed to our watercourses. First-order streams (the smallest streams under current stream classification systems, also known as headwater streams) are the first to swell with meltwater. These tributary stream channels fill and flow rapidly toward larger waterways, with water volume and velocity increasing as temperatures above freezing continue to contribute matter and energy to the system. Higher-order streams—like our rivers—accept the contributions from many tributaries; their levels crest as water levels in low-order streams subside.

All of this makes for some dramatic scenes around the area. Here at Severson Dells, one of the salient features of the landscape is the first-order stream that we call Hall Creek. It has its origins north of Montague Road and enters our forest preserve from the west, meandering through many switchbacks on its way to the Rock River. When the thaw began I went out to see how rapidly it would fill. On February 19 it was flowing freely. On February 20 it had overflowed its banks. And this was before the Kishwaukee or Rock Rivers had risen appreciably.

 Left:  Hall Creek begins to rise, February 19, 2018. Right:  Hall Creek in flood, February 20, 2018.

Left:  Hall Creek begins to rise, February 19, 2018. Right:  Hall Creek in flood, February 20, 2018.

A healthy, resilient waterway can accommodate flooding. The curves and bends of a meandering stream serve to limit the velocity of the water as it flows. The floodplain along the banks can accept the overflow, gently ushering the excess water downstream. The natural vegetation of the floodplain helps to protect the soil from erosion. Even during the dormant season, the roots of those plants are holding the soil.

The resilient functionality of Hall Creek was in evidence on February 20, the second day of the big thaw. Floodwaters overran the channel of the creek and spread out onto the frozen floodplain. The creek ran through braided channels and flowed over new terrain. The watercourse carried meltwater that might otherwise have found its way into basements or across roads. Unlike this stretch of Hall Creek, many of our streams have been channelized, ditched and straightened in an effort to increase tillable acreage and improve productivity—and to whisk away excess water as quickly as possible. Unfortunately, that engineered efficiency comes at a cost:  all of that fresh water is taken away when it might otherwise have been returned underground to recharge our fresh-water aquifers. Groundwater recharge is an important function of wetlands like the floodplain forests and riparian marshes that line healthy streams. Ditched channels with steep banks hasten erosion and carry sediment, rich in organic matter, rapidly away to places where the silt is likely to do more harm than good. The meanders of a natural stream like Hall Creek slow the flow of water, reducing erosion along the banks and allowing more water to go underground.

 The area in the foreground is usually well above water, with Hall Creek confined to a channel behind. The floodplain deftly carried the excess water downstream toward the Rock River.

The area in the foreground is usually well above water, with Hall Creek confined to a channel behind. The floodplain deftly carried the excess water downstream toward the Rock River.

Before the first wildflowers of spring open to the warming sun, our streams come alive, dancing with water drawn from melting snow.

Shrewd Observatons

As one of our volunteers and I were standing at the window this morning, watching the birds at the feeders (he was hoping for some redpolls), I saw a small, dark, furry body scamper across the snow toward the sunflower seed hulls scattered on the ground.  As quickly as it appeared, it disappeared behind a pile of snow. 

“A vole!” I declared.  Then I corrected myself.  “No, a short-tailed shrew!”

Neil put up his binocs as the animal reappeared, continuing its foray toward the motherload, and indeed, it was a shrew.  Blarina brevicauda – the only venomous mammal in North America (technically there are two species, the northern and the southern short-tails, but for the purpose of the article, I shall lump them together).

shrew crop1.jpg

Now I know what you are thinking:  venomous mammals?  Really?  Truly!  There are not many worldwide:  the duck-billed platypus, the Cuban and Haitian solenodons (which are foot-long, shrew-like animals), the Eurasian water shrew, and the short-tails.  Unlike the others, the platypus isn’t going around biting and “poisoning” animals – it has a spur on its hind foot that it uses in self-defense to inject venom into its enemies; the rest of them, however, use their venom to incapacitate their prey.

If you came out to our Science Saturday last month, you would’ve seen a short-tailed shrew specimen at the table where we were talking about the subnivean zone, for these small mammals are active all winter, scurrying around between the ground and the snow layer in a constant search for food.  Their metabolism is so fast that they must eat every two or three hours or else starve to death.  Therefore, they do not hibernate, and they are constantly on the move.  Invertebrates (insects, worms) make up the bulk of their diet, but thanks to their venomous bite, they can also immobilize mice and voles, taking them into their tunnels to consume later at their leisure (if such frenetic animals are ever “at leisure”).

What kind of venom are we talking about?  Is it dangerous to people?  What if one bites my cat, my dog, my kid?

The shrew’s venom is apparently similar to that of the cobra, chemical-wise.  It contains two kinds of toxins:  a neurotoxin that causes paralysis, and a hemotoxin that decreases the prey’s blood pressure and wreaks havoc on the circulatory system.  It seems that the shrew’s “purpose” for applying the toxin is not so much to kill its prey (for it is fully equipped tooth- and claw-wise to take out most of the food it finds), but rather to allow it to put prey into storage for later consumption – a paralyzed beetle or mouse will stay “fresh in the larder” until needed later on, when perhaps a quick snack cannot been found.

Knowing all that, you might still be worried about Fluffy, Fido or Freddy.  But fear not – if your cat or dog is bitten by a shrew, it will most likely not come to any harm.  Infection from the bite is probably of more concern than any reaction to the toxin.  Ditto for your child. 

Many years ago, I took a class on Winter Mammalian Ecology, and the guest instructor was Dr. Joe Merritt, who probably knows more about short-tailed shrews than anyone, thanks to his years of research at the Powdermill Biological Station in Rector, PA.  He claims to have been bitten many times by his research subjects, and has suffered little more reaction than what one would get from a bee sting.  However, like with bee stings, some people can react more strongly than others, so it is always wise to not handle wildlife unless it is absolutely necessary, and even then, use proper care and precautions (wear gloves).

shrew crop2.jpg

But I love these little guys.  They are energetic, easy to sneak up on (I was within a couple feet when I took these photos), they sing (yes – many years ago I heard one singing in the backyard while I was sitting on the grass, writing in my journal).  They have tiny little eyes, no external ear flaps, and fur that is unidirectional – all adaptations for a life spent primarily underground.

I have found many a dead shrew just lying on top of the ground in my lifetime.  Found two within about 15 feet of each other last summer right here in Rockford while I was walking the dog around our neighborhood.  Short-tailed shrews are very common (living ones, I mean, although deceased ones seem to be quite common, too).  I have often wondered why these small morsels remain uneaten by the predators that caught/killed them, and later on by scavengers, and after a bit of research I learned that birds will eat them (owls, hawks), but not so much mammals.  Supposedly this is because the shrews taste bad (and birds, apparently, are oblivious to this).  This could be from glandular secretions (located on the animal’s belly and nether regions), which turn a tasty mouthful into something that makes the predator (say a fox, or house cat) think twice about actually consuming it.

If you didn’t get to see the shrews last month, don’t fret the missed opportunity.  I have sent all the bodies from my freezer to a taxidermist and in a couple months I anticipate having specimens on hand to share with visitors.  In the meantime, keep your eyes peeled.  Watch for small furry bodies moving along the foundation of your house, or darting out to your birdfeeders.  Look for a pointy snout and plush grey fur.  Odds are, short-tails are in your back yard and you’ve just never had the opportunity to say hello.

Tale of the Thaw

 Fog forms above the snow

Fog forms above the snow

Our region in February saw an unprecedented nine consecutive days of measurable snowfall. And it was beautiful, powdery snow that invited me to explore the trails on cross-country skis, something I had scarcely been able to do during the prior winter, what with the dearth of snow. Those of us who enjoy the winter white were delighted by a foot-and-a-half of fresh snow on the ground. Here at Severson Dells we had a night hike on February 9 with about 20 of us trudging around through the drifts. A couple of folks even brought snowshoes for the hike.

Of course, it’s the middle of February and the sun is growing stronger every day. Even with air temperatures below freezing we can lose snow pack on sunny days as radiant sunlight thaws the surface of the snow. This week, tree branches high in the forest canopy were dropping loads of snow to those below.

And then we did get a real warm-up, a two-day thaw during which roofs came clean, watercourses flowed, and puddles formed. There was drizzle and fog—lots of fog.

Interestingly, we lose our snow pack faster under foggy conditions than we do under rain. Of course, air temperature, along with the temperature of the rainwater, will affect the rate of thawing, but generally the heat energy released by the condensation of water vapor over the snow (the formation of fog) is much greater than the energy transfer in a rain event.

We tend to think of water as an interim phase of H2O—liquid water. We know that water freezes into a solid we call ice (also snow crystals). And water evaporates into a gaseous form (we think of steam and water vapor). But H2O can change from its solid (frozen) phase to its gaseous phase directly, bypassing its liquid form, through a process called sublimation.

This can result in the kind of fog that we see during a thaw. And while we might not see sublimation taking place, we can see its effects. Have you ever noticed that snow disappears first from around the base of trees? Tree trunks receive and reflect solar radiation—and trees, like all living organisms, generate a certain amount of heat through basic metabolic processes. The snow around the tree absorbs this energy quite efficiently, resulting in sublimation of the snowpack closest to the trunk. You can see it in the photo.

 Snow disappears from around the base of trees by means of sublimation (direct transition to vapor).

Snow disappears from around the base of trees by means of sublimation (direct transition to vapor).

As we round the corner into the latter half of winter, enjoy the freeze, the snowfall, and the thaw—all part of the dance of moisture through the natural world.