The moth and the moon

Post by Jen Berlinghof

A full moon rises, a screen door slams shut, a katydid’s creaking calls echo, and a Luna moth (Actias luna) flutters in circles around the back porch light. We’re captivated by this green ghost of summer, concealed by broad leaves and seen rarely during the day, emerging at night only to mate for its few fleeting days of adulthood. How lucky it is that Luna moths live in the Lake County Forest Preserves in northern Illinois.

The bright green wings of the Luna moth (Actias luna) are instantly recognizable. Stock photo.
The bright green wings of the Luna moth (Actias luna) are instantly recognizable. Stock photo.

This charismatic insect is in the Saturniidae, or silk moth, family. It boasts a resplendent, three-to-five-inch wingspan adorned with large eyespots that flash and confuse predators. Their wings are also edged in reddish-brown, perfectly mimicking a twig with tiny buds, and they come with twisting tails like streamers to throw off the echolocation of bat predators.

Protective adaptations aren’t limited to the adult stage of the moth’s life cycle. Larvae make clicking sounds with their mandibles as warning signals before regurgitating intestinal contents in an effort to thwart would-be predators. And pupae wriggle and writhe around in their cocoons to avoid becoming lunch.

A Luna moth larva clings to a twig. Stock photo.
A Luna moth larva clings to a twig. Stock photo.

While the Luna moth makes its home in northern Illinois year-round, it spends the bulk of its time hidden away in a leaf-cloaked cocoon on the forest floor. Two generations of adult moths can be seen in the summer, one from late May to early June and then again from late July to early August. But don’t blink—these adults only live about a week, just long enough to mate and lay eggs. Not even long enough to need a meal, in fact. As adults, Luna moths live off the food they devoured as larvae, and have only vestigial mouthparts and no real digestive system.

Two Luna moths mating. Note the male's large, feathery antennae. Stock photo.
Two Luna moths mating. Note the male’s large, feathery antennae. Stock photo.

In the early morning hours, the thrashing cocoons grow still as the adult Lunas cut their way out of their silken cases using serrated spurs near the base of their wings’ front edge. Once freed, the crumpled creatures spend the remainder of the summer daylight inflating their wings with hemolymph (insect “blood”). When evening arrives, courtship activity follows as females release their perfume, known as pheromones, that males detect with their extra-large, feathery antennae. Males have bigger antennae than females for this purpose, while females sport larger abdomens, needed to carry their 200 to 300 eggs. Mating typically occurs after midnight and may last until dusk the next day.

While females mate only once in their adult life, males can mate each night of their short-lived adulthood. Once mated, a female will deposit her hundreds of eggs in small batches on the undersides of hickory and walnut leaves. Within a week, lime-green larvae speckled with magenta dots parade about, binging on these plants, growing and molting five times before spinning their silken, leafy pupae. The waning light of late summer and early fall signals the pupae to enter a state of suspended development, as they wait out the winter tucked away in cozy camouflage.

A leaf-wrapped Luna moth cocoon. Photo © Donald W. Hall, Entomology and Nematology Department, University of Florida.
A leaf-wrapped Luna moth cocoon. Photo © Donald W. Hall, Entomology and Nematology Department, University of Florida.
A Luna moth pupa. Photo © Donald W. Hall, Entomology and Nematology Department, University of Florida.
A Luna moth pupa. Photo © Donald W. Hall, Entomology and Nematology Department, University of Florida.

Luna moths blend in so well with the leafy landscape that they aren’t usually seen in their natural habitats. Their innate attraction to light—including artificial forms from porch lights to the overhead lights illuminating Little League baseball fields—present the best chance at a glimpse of their pale green majesty. Yet it also offers the moths’ predators the best chance at an easy meal. Scientists speculate that many nighttime flying insects, including Luna moths, use natural light sources from distant stars and the moon to orient their flight. Artificial lights confuse these insects and possibly overload the light receptors in their eyes, disorienting them and resulting in them swarming around outdoor lights. This behavior we witness on summer nights leads to serious risks to these insect populations.

Prevent swarming scenes such as this by turning off exterior lights as much as possible. Stock photo.
Prevent swarming scenes such as this by turning off exterior lights as much as possible. Stock photo.

We can help Luna moths and their fellow nocturnal critters by simply turning off exterior lights when possible, or switching to dim, low-voltage, motion-activated, or LED lighting. These are all less attractive to moths and other insects. Perhaps by doing this, we might miss out on the chance to see a Luna up close. We might just have to wait in the dark until the screen door quiets and the katydids pause, and rest assured that there will be a chance to glimpse the silhouette of this green ghost against the backdrop of the full moon.

Behind the bandit mask

Post by Brett Peto

You know them as raccoons (Procyon lotor). Though maybe trash pandas is more your style, a phrase that’s taken off since it first appeared on Reddit in 2014. (I can’t help but note the Rocket City Trash Pandas, a Minor League Baseball team, plays ball in Madison, Alabama). Or you could even know them as washing-bears, an old Germanic nickname bestowed on the species “because they have a habit of rinsing and softening their food in water before they eat it.” This moniker actually has a connection to the legendary naturalist Carolus Linnaeus, who created the Latin-based binomial nomenclature system and originally labeled the raccoon as Ursus lotor (“washer bear”). Whatever you call them, raccoons are commonly found in the Lake County Forest Preserves in northern Illinois.

It’s easy to spot one, of course, by its bandit mask: the patches of black fur bending below each of its eyes. This mask is nothing short of iconic, but it’s likely an icon with a purpose: “one hypothesis for the dark fur is that it may help reduce glare and enhance the nocturnal animal’s night vision.” There’s more to know, though, about these medium-sized mammals beyond face value—or just one feature of their faces.

A raccoon (Procyon lotor) peeks out of its tree den. Photo © John D. Kavc.
A raccoon (Procyon lotor) peeks out of its tree den. Photo © John D. Kavc.
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The joy of a feather found

Guest post by Nan Buckardt

I found a feather today and it stopped me in my tracks. There it was, tucked into the dewy grass—a single, beautiful feather just lying next to my sidewalk.

It’s not uncommon to come across feathers in my work at the Lake County Forest Preserves in northern Illinois. My naturalist brain immediately started to assess the discovery, analyzing it on a few key points.

The feather the author found just outside her front door. Photo © Lake County Forest Preserves.
The feather the author found just outside her front door. Photo © Lake County Forest Preserves.
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Jack-in-the-pulpit? Or Jill?

Guest post by Pati Vitt

The weather has varied a lot so far this spring. Minor snow squalls and hailstorms trade off with wonderfully warm, sunny days, which seem to call out, encouraging us to find the signs of spring. When the season brings all the beauty and promise of plants and flowers emerging from the winter, I feel as if I am seeing friends old and new once again. It’s rather comforting to know that regardless of what occurs in human society, spring carries on in the Lake County Forest Preserves in northern Illinois.

Many of the floral signs of spring are ephemeral, created by healthy populations of plant species that only emerge above ground for six to eight weeks—between the start of the spring warm-up and the closure of the canopy, when the trees grow a full set of leaves. Their live-fast lifestyle is an evolved response to their shade intolerance. Ephemerals need to finish flowering and fruiting while they have enough sunlight, and also put something away for a rainy day. They stash the sugar they make during photosynthesis in underground storage organs such as corms, bulbs, and rhizomes. The starchy carbon will see them through the winter into the next spring.

Some residents of our woodlands and prairies announce the arrival of spring in understated ways that require careful attention. The early-flowering harbinger of spring (Erigenia bulbosa), and later bloodroot (Sanguinaria canadensis), are two examples. Other signs of spring are exuberant and showy, such as the carpets of marsh marigold (Caltha palustris) at Ryerson Conservation Area in Riverwoods. And of course, no spring display is quite so welcome as large-flowered trillium (Trillium grandiflorum) in full bloom. (This sight is only possible when the white-tailed deer (Odocoileus virginianus) population is stable; otherwise these beautiful plants are eaten out of existence.)

Not all spring wildflowers are showy, though, and not all of them are ephemeral. Arriving later in the season, Jack-in-the-pulpit (Arisaema triphyllum) is one of the most common spring wildflowers in our woodlands. It’s usually entirely green in Lake County. Rarely, some maroon stripes may also be seen on the inflorescence, the reproductive portion of the plant.

Jack-in-the-pulpit (Arisaema triphyllum) is a beautiful resident of deciduous woodlands. It typically grows one to two feet tall. Photo © Lake County Forest Preserves.
Jack-in-the-pulpit (Arisaema triphyllum) is a beautiful resident of deciduous woodlands. It typically grows one to two feet tall. Photo © Lake County Forest Preserves.
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The solace of purple martins

Post by Jen Berlinghof

There’s solace to be found in the fact that the rhythms of nature march on. This spring, the sun still rises. The wild leek (Allium tricoccum) still pulses its verdant green arms through the pulpy leaf litter of the forest floor. The birds still surge through the skies as they migrate to and through the Lake County Forest Preserves in northern Illinois. Like us, some of these birds are inclined to congregate in large communities. Over the years, the colonies of a particular species, the purple martin (Progne subis), have become largely reliant on people to provide shelter for their nesting flocks.

Two purple martins look at each other on the ledge of a martin house. Photo © Phil Hauck.
Two purple martins look at each other on the ledge of a martin house. Photo © Phil Hauck.
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Here comes the Sun (Lake)

Post by Brett Peto

The sky to the west was robin’s egg blue, a clearing in the day’s dose of clouds. They had just sneezed a handful of snow, already melting. I drove with the radio off. I didn’t know whether to wear my regular hiking boots or a pair of Wellington boots I’d packed at the last moment. The trail could be soggy, or maybe not. I was on my way to Sun Lake in Lake Villa, part of the Lake County Forest Preserves in northern Illinois.

For this month, I decided to revisit the idea behind my February 2019 post, when I explored a new-to-me preserve and wrote up my observations as a virtual tour. Readers seemed to enjoy it, and I enjoyed circling another name on the map I keep at my desk. So, here I was, about a year later, ready to chronicle another tour. Find a comfy chair and a warm mug. Here’s a snapshot of Sun Lake as I saw it.

The view looking south from the parking lot at Sun Lake. Photo © Lake County Forest Preserves.
The view looking south from the parking lot at Sun Lake. Photo © Lake County Forest Preserves.
Always look at the trail map before you go. Photo © Lake County Forest Preserves.
Always look at the trail map before you go. I walked the trail loop clockwise. Photo © Lake County Forest Preserves.
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Get to know groundhogs

Post by Jen Berlinghof

Late last summer, I literally watched a groundhog (Marmota monax) fatten up before my eyes. He’d made a burrow in the field outside my office window and frequently visited the rain gardens around the Edward L. Ryerson Welcome Center in Riverwoods, part of the Lake County Forest Preserves in northern Illinois. We watched him scamper back and forth, snipping flower tops here and there, always with a mouth crammed full of flora.

Fast forward to early February, and as I look out across the same field, now dotted with small snow drifts punctuated by tufts of grasses gone tawny, I think about that groundhog curled tight in his burrow and deep in hibernation, oblivious to the hubbub of a day in his honor.

Groundhogs (Marmota monax) are active during daytime, particularly early morning and late afternoon. Stock photo.
Groundhogs (Marmota monax) are active during daytime, particularly early morning and late afternoon. Stock photo.
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Monogamous minks? Not quite.

Post by Brett Peto. All mink images and footage by John D. Kavc.

Yes, it’s almost that time of year. American mink (Neovison vison) mating season. I know, I’ve been waiting for it, too. February is celebrated for human romance: fancy dinner dates, shiny gifts, and long walks on the Des Plaines River Trail. But it’s useful to step out of our human-focused perspective once in a while. And thanks to our comprehensive Wildlife Monitoring Program, we know minks live in the Lake County Forest Preserves in northern Illinois. So, let’s examine why humans aren’t the only species that looks forward to February 14.

A mink (Neovison vison) peeks over a fallen tree. Photo © John D. Kavc.
A mink (Neovison vison) peeks over a fallen tree. Photo © John D. Kavc.
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Finding the right angle

This gallery contains 10 photos.

Post by Brett Peto

I keep thinking about angles. Not the kind you measure with a protractor, but those you measure with your mind. The angle of a story, a conversation, or a project. Photography, of course, uses physical angles—where’s the camera pointed? is the sun directly overhead or is it the sweet time of golden hour?—but the best photos make you want to see even more. They make you want to break open the frame and soak in every bit of the Lake County Forest Preserves in northern Illinois.

Since it’s nearly the end of 2019, I thought I’d turn 180 degrees and peruse the photos uploaded to our group Flickr pool since January 1. Suffice to say: we’re spoiled. Spoiled with the beauty of Lake County’s flora, fauna, and natural areas, and the talent of the photographers who capture it for everyone to see. Trees and shrubs in their bright fall wardrobes on either side of a trail draining into a vanishing point. A sandhill crane (Grus canadensis) with both wings up like a paper airplane as it dashes to take off. A whirlpool of stars spun around a rich blue sky over a tranquil wetland.

I’ve gathered these moments plus seven more below, but that’s only a small taste. I encourage you to browse the rest of the visual buffet as we make the turn out of the 2010s into the 2020s. And, hey! You might become inclined to upload that shot living on your phone, camera, or computer.

"Night Moves." Photo © reddog1975.
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Give thanks for turkey vultures

Post by Jen Berlinghof

Come late November, most of us have turkeys on the brain. But a different type of turkey is taking to the skies at this time of year on its annual migration south: the turkey vulture (Cathartes aura). You can spot them in the sky or on the ground in the Lake County Forest Preserves in northern Illinois.

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