Juneberries!

 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.

Glow

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 apart...in 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, bugwood.org)

Virginia creeper tendrils with pads (photo credit:  John Cardin, OSU, bugwood.org)

 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.

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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.

 

Hazel

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).

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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).

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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.

Winter Walk

OH, People - get out there!  It may be cold (about 4*F), but the sun is out, the sky is blue, and at 8:30 this morning it was a GLORIOUS time to be out walking the trails here at Severson Dells!  Yesterday's snow, with its giant dry flat flakes, is only about 2-3 inches deep, and it is PERFECT for finding tracks, for decorating last year's dried flowers, and transforming the ground into a sparkling sheet of rainbows.  SO beautiful. 

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It's too cold?  Heck - bundle up!  Truly, there is no good excuse to not go out on a morning like this.  Today I had on my boots, two pairs of wool socks, a pair of thinnish longjohns under my usual nylon pants, a turtleneck shirt, a sweatshirt, a wool coat, woolly mittens, alpaca scarf and a wool hat.  That's it.  Nothing fancy.  And I was plenty warm (well, until the end of my walk, when my legs were starting to get a bit chilly).

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And what did I see?  Amazing things.  I was anticipating photographing snow on stuff (last year's flowers, old bird nests, branches and twigs), but I was blessed with so much more.

 Did these coyotes find something to eat here, or was it a territorial marker?

Did these coyotes find something to eat here, or was it a territorial marker?

Coyote tracks.  Coyote tracks galore.  I haven't seen such coyote tracks since I was living in the Adirondacks.  I found scent sites, possible capture sites (vole?  mouse?), sites where snouts were thrust into the snow.  There were interesting spots where a coyote walked a circle... why?  No idea, but interesting.  

 Classic otter slides and 2x2 bound.

Classic otter slides and 2x2 bound.

And then there were the otter tracks.  OTTERS!  I'm still so excited about them that I am nearly vibrating!  There was a slide down a hill, slides into and out of the open water (and the stream is only a very few inches deep), and very distinct footprints.

 Mouse tracks on the frozen creek.

Mouse tracks on the frozen creek.

Oh, sure, there were deer, squirrel and mouse tracks, too, but it was the coyote and otter tracks that made my morning.  

In fact, we are going to head back out in a little while, my coworkers and I, so I can show them what I found.

If you go out for an explore on a wintery morning like this, here are my tips:

  1. Be sure you are dressed for the weather (see above).  Nothing will ruin a winter morning more than being cold.
  2. Keep your eyes (and ears) open!  You never know what you are going to find.
  3. If/when you find tracks, don't walk on them!  Walk around, to the side, or step over.  Leave the integrity of the tracks intact so others can enjoy them as well.
  4. Try to figure out the story the tracks tell.  Was it one animal or more?  Which way was it going?  Was it looking for something, or "commuting" - yes, with practice you can tell the difference.  

Winter walks are great, because we now see all the stuff that is going on that other times of the year we are oblivious to simply because we do not see the evidence of the animals' passing.

Weasel Wonderings – Part One:  The Badger

I love weasels.  Once upon a time I had ferrets, which are amazing, curious, and slightly destructive animals that are full of whimsy and are thoroughly delightful.  I also used to live in a region that was full of many weasel species:  short- and long-tailed, mink, marten, fisher, otter (and, historically, wolverines) – I loved following their tracks and pondering their lives.  Northern Illinois has its own collection of weasels, some of which overlap with the ones I used to know (short- and long-tailed, mink, otter), and others that are entirely new (least and badger).  I eagerly anticpate learning more about these species.

Let’s start with the badger, which is high on my list of “gotta see” critters.  To begin with, it is just so beautiful!  The white, black and brown markings are simply stunning – who wouldn’t want to see something so gloriously patterned?!?  Next, it has an amazing build:  broad and short, large and powerful.  It lives underground and is a known to be ferocious hunter. 

During my six years living in southern Michigan, I heard of badgers being in the region, but finding one was nearly impossible.  Oh, there were rumors (“they are out by the prison”), but I never found anyone who knew exactly where I could see one.  Like the moose, it looked like it would remain out of reach, a mere pipe dream for me.  Then, during my first few weeks here in Illinois, a coworker and I were visiting Ferguson Forest Preserve and he pointed out some burrow openings saying “those are badger dens.”  Really?  How can you tell? (According to him, they have a D-shaped hole, which is highly diagnostic.)  Might we see one today? (No, we didn’t.)

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I actually saw my first badger this summer.  True, it was taking a permanent nap on the side of the road down near Sycamore, but you’d better believe I pulled over and started taking photos (see above)!  I really should’ve put it in my car and popped it into the freezer for later taxidermy, but I had the usual excuses:  the dog was with me, I had no plastic to protect the car, it was a very hot day and who knew how long it had been dead…

Still, it was a beautiful animal and I needed to know more.

In my research, I have found the usual common information about badgers:  they are primarily fossorial (live underground), can dig at tremendous speed (faster than a person with a shovel), are ferocious fighters (I just watched a video of a badger fighting a fox…it was impressive).  I read up on the history of badgers in Illinois (ridiculously common pre-European settlement; declined precipitously in the 1800s due to people digging up the prairie, their primary habitat; started to make a comeback in the early 1900s thanks to small farms with diverse crops, which provided fair habitat, especially for the badger’s primary food – rodents; dropped again in the 1950s thanks to modern agriculture with its monocultures, heavy equipment, and reliance on chemicals for fertilizer, pest and “weed” control; and today is not only considered to be “recovered,” but is also once more allowed to be trapped either for its fur or as a nuisance animal).  I also found some questionable “facts” (i.e., the lower jaw locks making it impossible to disassociate from the upper jaw – only one reference to this and not verified by any research, nor is it mentioned in my authoratative book about skulls). 

But then I came across something that has me puzzled, and like a mountain lion, my intellectual jaws have clamped down on this one detail and won’t let go:  badger hair is sought for use in shaving brushes because it is super absorbent – holding water apparently makes for lavish quantities of lather, which the person in search of a superior shave apparently wants. 

Wait a minute, says I.  How in the world would having super absorbent fur be of benefit to an animal that spends its life underground?  Everything about this animal is adapted to its fossorial life:  a thin transparent membrane over each eye (like a contact lens) to protect it from debris; small ears fronted with long stiff hairs to keep out flying dirt out; powerful neck and shoulders, and huge feet with long claws, all ideal for rapid digging through even the hardest “soils” (yes, there are records of badgers digging through asphalt and concrete); the squatty body and triangular head both designed for maneuvering in tunnels.  But nothing, NOTHING suggests any sort of evolutionary advantage to having water absorbent fur.  Badgers are even known to be good swimmers (that was a surprise), so here is a good reason not to have absorbent fur:  it would make one heavy in the water (potential drowning hazard) and it would reduce any insulative properties the fur would have (hypothermia).

I tracked down the names of a couple researchers who did work on badgers, but that was in the 1990s, and I cannot find any current contact information for them.  And any badger research I did find was only looking at ecosystem type stuff:  where they lived, what they ate, how the population was doing, etc.  No one (online) has an answer to my question.

So I toss my query out to the Universe:  if anyone knows why badgers would have absorbent fur, please let me know.   In the meantime, if you know of a badger den where I can sit down with my camera and observe their comings and goings, I would love to know that, too. 

It's All Happenin' Below the Snow

I’ve been thinking a lot lately about a very special, ephemeral habitat.  It forms in the winter, is home to many small mammals and invertebrates, it helps plants survive the deep freeze, and, it turns out, it is also vital to carbon sequestration.  It is the Subnivean Zone.

I thought I knew enough about this microhabitat to create a pretty good introductory learning experience for our next Science Saturday (Jan. 27), but, as with all things science, it is always good to do a little research to see if anything new has been discovered since the last time I read up on the subject.  And then I thought to myself:  Self, you know about the importance of the subnivean…but with less and less snow cover, and very cold temperatures like we’ve been having these last few days of 2017 and early 2018, how are the animals that depend on the subnivean surviving?  Hmmmm.

I sent an email to a small mammal ecologist I know asking if she knew of any current studies.  She’s on vacation right now, so I also turned to the internet to see if there was any research going on.  Wow – have I been enlightened.

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The subnivean layer (from the Latin “sub” meaning below, and “nives” meaning snow) has long been known by the Inuit.  They call this special snow zone Pukak:  it is the space that forms between the ground and the snow pack.  When the first snows fall, vegetation bends over creating supporting arches that hold the snow up.  The subnivean doesn’t really get created, however, until there is a minimum of six to twelve inches of snow.  Fluffy snow.  Fluffy snow is full of air pockets, and air pockets mean insulation:  the snowy layers above the ground now protect the ground from the bitter winds and temps that swirl above.  Between the heat radiating from the Earth (even when the ground is frozen), and the insulating qualities of the snow, the subnivean zone stays at, or near, a toasty 32 degrees Fahrenheit.

This may not seem balmy to you or me, but to those animals that live there, it is quite acceptable.  It is warm enough for them to remain active throughout the winter.  Mice, voles and shrews create vast networks of tunnels through the arched vegetation (surely you’ve seen these tunnels and trails after the snow melts in the spring).  A keen eye can also pick out “kitchens” and latrines – all sorts of chambers where daily life takes place.

The mice and voles are eating plants:  seeds and grains they stored over the fall, and still-green vegetation that is also hanging on in the mild climate of the subnivean.  Shrews are shrewd hunters, going mostly after invertebrates (beetles, worms, etc.) that they find hunkered down in the leaves and spaces under logs and rocks, but they will also take another small mammal if the opportunity presents itself, especially the short-tailed shrew, which is famous for its venomous saliva (that is a blog for another day).

Now, all of this I knew…no news there.  It was, however, when I started to read about the biota of the soil and leaf litter that I realized that there is more to this subnivean layer than I suspected.  Than anyone suspected. 

Let us begin by considering what happens when there is no snow cover, or the wrong kind of snow cover.  Recall that I said the snow had to be fluffy; you get fluffy snow when the temps are cold.  With climate change we are getting heavier, wetter snows more and more frequently.  These snows are much more compact, which means there are significantly fewer air spaces.  This means the snow has less insulative properties, which means the subnivean will no longer be warm.  It also means that there is less air exchange, resulting in a build-up of carbon-dioxide, which can suffocate the animals that are living there.

This also has an effect on plants:  no insulating snow means that the ground freezes harder and dries out.  Roots dry out; roots freeze.  Plants suffer the stress of these conditions and if it happens long enough, the plants will die.  We’re not just talking dandelions and ferns; we’re talking trees, shrubs…our forests and prairies.

And then there are the microorganisms, the things that live in the soil. 

Microorganisms include bacteria, fungi, and protozoans.  Toss in the small invertebrates, too.  Collectively, these are the tiny beings that, truly, make life on this planet possible. 

We tend to think of winter as a time when the “earth sleeps.”  It is easy to see why:  trees and shrubs have dropped their leaves, insects have disappeared, many birds fly south, and a handful of animals hibernate.  The world seems quiet and empty.

The thing is, it’s all happening beneath the snow!  Winter is when things really get hopping underground – great biological activity is going on and we are oblivious to it.  And all this activity is creating lots and lots of CO2.  Paul Brooks, at The University of Colorado Boulder, is one of the handful of people doing research on this, and he has discovered that the amount of CO2 that is released into the atmosphere is directly tied to the amount (and type) of snowfall.  In a nutshell, if things freeze before there is enough snow to provide insulation, microbes (et al) feast on the ruptured tissues of the plants and critters.  The more plants and organisms that die, the more tissues that are ruptured, which means the microbes go to town…and the more active they are, the more CO2 they produce.  Brooks’ research has shown that these trends can release 25-200% more CO2 than “normal.”

See that:  one more piece of evidence that climate change is doing irreparable harm.  Without adequate snow, fluffy snow, creating the subnivean zone, protecting plants, small mammals, invertebrates and microorganisms, we get yet another source of CO2 releasing into the atmosphere.

Many folks moan about the snow – they don’t like the cold, they don’t like shoveling, they don’t like driving in it.  But, y’know, it’s not about us.  It’s about this spaceship we call Earth, the only home we have.  And snow, which supposedly covers 40% of our landmasses most of the year, is vitally important for our continued survival.  It’s not just that the snowpack provides the water that keeps ecosystems from becoming deserts; the picture is so much bigger than that. 

This is why I love science.  I love that we have curious minds that ask questions and then set about trying to find the answers to those questions.  I love learning about all the intricate ways that everything on this planet is connected.  I love learning about new things that make me think “gee, I never thought of that before!”  And I love that learning these things allows us to imagine new ways to work with nature.

I hope you do, too, and that you will join us once a month this year for our Science Saturdays, where we hope to share some new science with you that opens up new realms of inquiry and fascination in your minds.  See you January 27th!

 

Avian Dynamics

My desk affords a view to the northwest, from the vantage-point of a second-story window that overlooks a cluster of bird feeders. My snowy view of winter white is studded with color:  punctuated by the plumage of the avian visitors that flock to the feeders and congregate in the branches of the Viburnum next to the building. The birds offer an affable distraction, flitting from branch to branch, swooping down to feed on seed, calling or chuckling, fluffing and preening.

Against the snowy backdrop, the brilliant Cardinals and effulgent Blue Jays command the eye. More subtle are the Dark-eyed Juncos, the so-called “banker birds” in their conservative gray suits. Striped Goldfinches in their subtle winter plumage linger in large numbers at the feeders. Woodpeckers, the Downy, the Red-bellied, the Hairy, are especially fond of the suet feeders.  Chickadees, White-breasted Nuthatches, and House Finches round out the usual assembly.

On a recent winter morning, my attention was drawn by the repeated calls of Blue Jays—cries that clearly called alert, alarm, warning. Moving to the window, I looked down to see the bird feeders vacant and the Blue Jays, Cardinals, Chickadees, and Juncos amongst the branches of the Viburnum. Like the other birds, I understood the Blue Jays’ alarm calls to mean that a predator was about. Peering through the window, I scanned the area, wondering whether I might spy a coyote or a feral cat prowling among the shrubs, or perhaps a Red-tailed Hawk perched and alert.

Then she flew by, close to the building and just below my window:  a Cooper’s Hawk with her slate-blue back and narrow, barred tail.

 a Cooper's Hawk in flight

a Cooper's Hawk in flight

Birds account for the predominant portion of a Cooper’s Hawk’s diet, so the feathered flyers around our bird feeders did well to heed the Blue Jays’ warnings. Coopers’ Hawks are extremely agile in the air, accustomed to maneuvering between the branches in our oak woods and savannas as they hunt, generally capturing their meal on the wing. An accipiter, the Cooper’s Hawk is less inclined to soar like a buteo, adrift on a thermal of air. With a long, rounded tail serving as a nimble rudder, a Coopers’ Hawk hurtles through narrow spaces in the tree canopy, dipping and twisting to avoid colliding with obstacles while bearing down on its swift passerine prey. I think of the Cooper’s Hawk as a classic savanna bird.

For a little while she came and perched in the Viburnum, sending the other birds scattering. She didn’t, however, linger in the vicinity of the feeders, so soon the other birds were back to their banquet, the snowy scene flecked with birds bedecked in plumage of red, white, blue, and gray.

Frosted Windowpanes

I like winter; I like snow.  I like frost and ice, too.  All of it is delightful, as long as one doesn't have to drive in it, or shovel massive quantities of it.  So when I woke to a gorgeous Christmas morning this week, after the previous day's hazardous driving, I was enchanted.  The ground was white with a whopping 1.5-2" of snow, the sky was a cloudless blue and the sun shone brilliantly, transforming the outdoors into a magical wonderland.

 "Mountain Range" formed on Hall Creek - probably a good 2-3 feet long.

"Mountain Range" formed on Hall Creek - probably a good 2-3 feet long.

Back at work two days later, after the deep freeze of Boxing Day, I was in awe of the frost patterns I found out on Hall Creek when I walked out there with the four- to six-year-olds of our Winter Day Camp.  There was an incredible "mountain range" formed by the moving water, and on either side of it were fronds of feathery frost and spokes of toothpick-like frost.

 Frost feathers (hoar frost) on Hall Creek.

Frost feathers (hoar frost) on Hall Creek.

In our "conference room," where staff often eat lunch, we have some beautiful frost growing on the windows that face the butterfly gardens.  When the sun hits the ice just right, it sparkles with a kaleidoscope of colors, which are nearly impossible to capture with the camera.  They appropriately call it "fern frost," these graceful lacey creations that adorn our windows.

 Close-up of the frost on the conference room windows.

Close-up of the frost on the conference room windows.

It all seems so magical - and yet, the mechanics of frost formation are pretty basic:  water freezes.  Yes, it really is that simple.  

First, let's quickly review the three states of matter:  solid, liquid and gas.  Everything around you is either a solid, a liquid or a gas.  When it comes to water, you have ice (solid), water (liquid), and water vapor (gas).  We are a water planet, and there is almost always water around in one form or another...maybe not in great quantities, but it is usually there.

So, when the temperature drops below freezing, water vapor, which is in the air all around us, condenses on cold surfaces and turns directly into ice, skipping the liquid stage (at temps above freezing, it condenses as a liquid, forming dew).  Water vapor is made up of tiny tiny particles of water, and each particle finds something to cling to and freeze - this is the nucleus of the frost formation.  Additional water vapor clings to the sharp edges of this formation, and it, too, freezes, forming a tiny little ice crystal.  As more water vapor collects and freezes, the ice (or frost) crystal grows.  

Tiny imperfections on the surface where the ice is growing (like scratches on your window, or even the film/streaks left behind by window cleaners) can influence how the crystal grows.  So can wind.

The beautiful frost patterns we found on the stream are a type of frost called hoar frost (from the Old English word hoar, which refers to something being grey or white).  Hoar frost is formed when there is a lot of moisture in the air, which one would definitely have at a stream or pond...or if fog had formed overnight and then froze on surfaces.  When there is a lot of moisture present, one is almost guaranteed incredible shapes and patterns in the frost...and it will likely be a beautiful opaque white color (hence the name).  Add some wind to the picture, and you can get amazing fingers and spires of frost...all pointing in the same direction.

Most newer houses, or older houses with new windows, do not get frosty windows - a good thing when it comes to your heating bills, but kind of sad if you enjoy the beauty of frost formations.  This is because you have to have windows that are only single-paned:  one side of the glass is in touch with the cold air outside, and the other side is in touch with the warmer, moister air in your house.  When the two collide on your window pane - voila! - frost forms.  Newer windows are too well insulated - the air trapped between the two panes prevents the intimate contact needed between the cold air outside and the warm, moist air indoors.

Whenever I see frost creations, I grab my camera and try to capture them "on film."  As soon as the surface they are growing on warms up, they disappear, so I immortalize them as best I can.  But even without a camera in hand, they are a delight to behold.  So don't let the chill of this cold snap keep you from discovering the wonders of winter - get out there and explore!

Unmitigated Gall

When is a pinecone not a pinecone? When it grows on a willow.

Now that the leaves have fallen from the trees we can see details in the landscape that we might miss during the growing season. Sometimes the little things call our attention or capture our imagination. I think of willow thickets and the distinctive appearance of the willow pinecone gall, an elegant appendage seen at the tips of willow twigs. These may be prominently visible now that the vegetation has gone dormant for the winter months.

As a budding botanist, I puzzled over these vegetative structures. I knew that willows, in the genus Salix and the family Salicaceae, do not produce cones (like conifers, such as pine and spruce) nor strobiles (like birch and alder). Yet I often noticed conical growths on willow wands, with imbricate bracts, leaf-like and layered, arranged in a perfect spiral toward a pointed tip, looking for all the world like a gray, leafy pinecone. And I saw them only on willows. Specifically on three native species:  pussy willow (Salix discolor), heart-leaved willow (S. eriocephala), and sandbar willow (S. interior).

 A willow pinecone gall in winter shows hardening of the scales that protect the larva of the gall midge within.

A willow pinecone gall in winter shows hardening of the scales that protect the larva of the gall midge within.

The leafy, cone-like appendages in question are galls, produced by a little gall gnat midge named Rabdophaga strobiloides. The insect’s scientific name is telling:  Rabdo means rod (or branch, twig); phaga refers to the feeding habit of the organism; a strobile is a structure composed of woody scales in the form of a cone; the suffix, oides, says that something “looks like” the preceding. So the scientific name translates into “twig-feeder” that produces a gall that “looks like a strobile.”

While we are familiar with the knowledge that many insects and other animals feed upon the leaves, stems, and flowers of plants, consider how striking it is that some of these insects also induce plant growth in such a way as to provide shelter, as well. Yet, here in the United States, there are more than 2,000 types of insect galls, of which some 700 are produced by gall midges related to Rabdophaga strobiloides. Some 39 of them focus exclusively on willows.

In the case of our pinecone willow gall midge, females deposit eggs in the new growth of willow twigs during the spring. When larvae hatch from the eggs they produce a chemical that causes the willow to produce aberrant growth and thus the gall begins to form. (In some insects, the deposition of the egg includes a chemical that initiates the gall-formation process.) The midge larvae undergo three instar phases, each of which contributes to the gradual formation of the gall. (Early in the season, the nascent gall is round; as the year progresses, the gall assumes its familiar cone shape.) Mature larvae overwinter in the galls and pupate in the early spring. We can expect the adult to emerge from the gall in late April or early May.

So, this winter, as you roam the margins of frozen wetlands, look for the “pinecones” that appear on willow wands—and know that you are seeing the winter palace of a tiny midge.