Who's Hiding in the Tapestry?

From a distance, the forests of July look like a lush tapestry of green. But when you step into the loosely woven strands and take a closer look, the leaves are etched with feeding trails, dissected by holes of all shapes and sizes, and covered with the debris of life. It’s a principle of ecology, of course, that every Being is food for someone else.

Cattails, for example, are food for me! Before their flower spikes explode with pollen and become those brown sausage-shaped seed heads, the dense cylinders of their male flowers are a tasty green vegetable. Simply husk them like sweet corn, boil for 10 minutes, and eat with butter and salt. Just like a corncob, there’s a central stem you must nibble around. In Northern Wisconsin, this part of the plant becomes edible in late June.

Harvesting the male flower spike on a cattail. 

A few weeks ago while I was tromping through a cattail stand to harvest dinner, I noticed that some of the cattail leaves were folded over at the tip into a triangular origami box. I set down my bag of flower spikes and used both hands to unfold the leaf. White silk in the seams stretched and tore. The inside was lined with sheets of silk as well, and hidden below this gossamer blanket was a cluster of beige eggs. In a flurry of legs, someone small and brown escaped from the back corner of the box and dropped to the ground. Who had I disturbed?

The next origami leaf I opened much more slowly, and was rewarded with the sight of a pretty little spider covered in silky brown hairs. She stared at me with her ebony face from beyond her pile of eggs.

Riparian sac spiders fold a cattail leaf into a little origami home in which to guard their eggs. Photo by Emily Stone.

All spiders can make silk, but riparian sac spiders like this one don’t build webs. To hunt, they wander through the night, hoping to stumble on an insect or arthropod the right size for their next meal. When a female is ready to lay eggs, though, she finds the leaf of a monocot—plants like grasses or lilies with parallel venation—and bends it around herself in a clockwise direction. She uses silk to hold everything tight and to line the enclosure, then lays her pile of eggs. The leaf isn’t crimped; it remains green and living.

This tidy structure has been described as both a nursery and a coffin. The mother spider will never leave the structure again (except if disturbed by a curious naturalist). Instead, she guards her eggs against the marauding hunger of other female sac spiders. By some accounts, she dies just before the eggs hatch, and the young consume her body as their first meal. It is the ultimate maternal gift.

Sac spiders as a group are common around the globe, and this particular species has been found in Russia, Mongolia, China, Japan, across the Northwoods, and in Cable, Wis.

In looking up information on the Bug of the Week blog by Kate Redmond, I discovered that sac spiders are classified as “leaf folders,” while other leaf architects are “leaf rollers” or “leaf tiers.” All of these insects and spiders use silk that contracts as it dries to shape leaves into shelters.

S. W. Frost, in the 1942 book Insect Life and Insect Natural History, described that “As the strands dry, they shrink and pull the edges of the leaf inward. New and shorter strands are then spun which in turn shrink and pull the edges of the leaf closer together. This is continued until the edge of the leaf is drawn completely over and is fastened with other strands of silk…”

I set out to find examples of the other two leaf architects. It didn’t take long. While walking a section of the Superior Hiking Trail, I spotted large-leaved aster leaves with one edge curled inward toward the midrib. Brown trails through the tissue indicated that the homeowner was mining the leaf material from inside their hidey-hole. I opened one to discover a sprinkling of black frass (poop) and no resident. I decided not to disturb anymore. Micro-moths in the family Tortricidae are some of the most common leaf-rolling architects, and are my top suspects. This group includes spruce budworm, a pest who had sewed fir needles together nearby.

A leaf rolling insect has used silk that shrinks as it dries to construct a shelter in this large-leaved aster leaf. Photo by Emily Stone.

Spruce budworms are leaf-rolling moth larvae likely related to the architect of the leaf above. They are currently killing quite a few fir and spruce trees in Northern Minnesota. 

Photo by Emily Stone.

In a rocky section of trail, a patch of pearly everlasting leaves caught my eye. On several plants a few of the topmost leaves had been sewn together into a messy vase. Without even opening the structure, I knew that this was the work of a spikey black caterpillar who will metamorphose into an American painted lady butterfly. They scrape pale fuzz off the leaves’ surfaces to line their nest, and also munch on the inner walls of their home.

American painted lady butterfly larvae sew pearly everlasting leaves into a vase-shaped hideaway. Photo by Emily Stone.

The hiding caterpillars above will metamorphose into this beautiful American painted lady butterfly. Photo by Emily Stone. 

Everywhere I looked, the signs of leaf-eaters abounded. And then, in a flash of feathers, a bird dove into a bush. Behind the screen of twigs, a male chestnut-sided warbler hopped nervously with two different colors of caterpillars dangling from his beak. When he sensed my focus had strayed, he dove away to his nest. Those larvae were almost certainly leaf-eaters, and they were about to become birds! The abundance of summer is a great time to witness ecology in action.

Can you spot the male chestnut-sided warbler with two caterpillars in his mouth?
Photo by Emily Stone. 

Emily’s third book, Natural Connections3: A Web Endlessly Woven, is available to purchase at www.cablemuseum.org/books and at your local independent bookstore, too.

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Summer Calendar is open for registration! The Museum’s new exhibit, The Wetland Way is now open! Discover how life thrives at the intersection of soil and water, and why we must care for these special places as they care for us. Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

Stalking Wonder

On a warm day at the end of June, the whole world buzzed with life. Painted turtles slid off sunning logs as we paddled up the channel into Big Bay Lagoon on Madeline Island. Song sparrows whistled and trilled their complex songs from the tops of scrubby black spruce trees. Through their trunks I spotted a veritable garden of pitcher plants blooming on a lawn of Sphagnum moss. As we stepped carefully onto the warm wet sponge of the bog mat, a bumblebee hummed inside the nearest burgundy bloom.

I don’t think I’ve ever seen so many pitcher plants blooming in one place! 

Photo by Emily Stone.

Although it’s hard to walk fast on soggy Sphagnum moss while not crushing the pitcher plants, I did my best to dart from one treasure to the next. Kevin followed behind at a more meditative pace, searching out the singers with his binoculars.

I barely caught the flash of brown out of the corner of my eye, but Kevin had a clear view. He followed the flight path of the bird until they landed on the far side of a small channel lined with arching sedges. Despite the bird’s pinstriped camouflage blending seamlessly with the tall grass, and having never before seen one in the wild, his identification came instantly: American bittern!

Can you spot them?

These birds of mucky marshlands are hard to spot. It’s not just because of their cryptic coloration, but also because we’d sink into the mud of their damp, reedy habitats. During my graduate school project monitoring wetlands in Maine, we spooked bitterns into flight many times while bushwhacking to our remote field sites. The kok-kok-kok call they made in agitation harmonized with the squishing of our boots.

Now a bittern was stalking along barely 20 feet away, and we could easily see the huge, bony yellow toes that kept them from sinking in. As the heron clung to an insubstantial hummock of dried grass, their mottled brown rear wiggled in anticipation as their striped neck stretched forward. Then legs, feet, and neck all uncoiled at once, launching the bittern’s spear-like beak into the water’s edge. Their white throat patch pulsed to gulp down their prey. Frog? Tadpole? Fish? Bug? We couldn’t see, and their diet is diverse.

Watch the bittern hunt!

As the bittern stalked a few steps forward to seek their next target, we stalked them, too, creeping along our shore to keep them in view. And although they peered intently into the water with their yellow eyes shaded by a prominent brow ridge, they didn’t seem to notice (or care about) us. They just continued their strategy: several quick steps forward to a new hummock. Freeze. Stare intently into the water. Strike. Gulp. Repeat. From the movement of their throat, we figured they had nearly perfect hunting success. Although they are known to snatch dragonflies from flight, they ignored the shimmering-winged insects darting above the grass. Perhaps they prefer easier and juicier prey. Like owls, they can regurgitate the indigestible bits.

Strike!

For several minutes we watched in awe as the bittern worked their way down the shore. Then the walking on our side of the channel became too treacherous to navigate without long yellow toes and we turned back to explore the rest of the lagoon. For the next several days we exclaimed about our good luck at having a front-row seat for such a rare show.

Pink Panther ;-)

Bitterns hunt alone, mostly at dawn and dusk, and are said to be easier to hear than to see. Their deep booming, gulping calls travel far across marshes, but the male “thunder-pumpers” are vocal only during their spring mating season, and so it’s not even that easy to hear them. Add to that bitterns’ decline in parallel with the decline of their wetland homes, and we’d resigned ourselves to admiring their mystery instead of enjoying an encounter.

American bitterns stand quietly while the get ready to strike at prey like fish or frogs.
Photo by Emily Stone.

Perhaps we were too pessimistic. Over the past several years I’ve spotted bitterns a few times. One summer two juveniles watched me bike by from the mowed roadside, the remnants of downy baby feathers sticking out from their new brown coats. So ingrained is their instinct to hide by standing with the striped neck vertical and their beak in the air, sometimes swaying gently like grass in the wind, that they will do this even when out in the open. A couple years prior, I’d watched a juvenile with the same telltale halo of down stalk insects in a short-cropped field on my way to pick blueberries.

Protected wetlands like Big Bay Lagoon are essential to American bitterns’ continued existence, as are similar habitats on their wintering grounds farther south. Protected wetlands are great for paddlers, too. After we left the bittern, we stalked feasts of wonder in the form of hot pink orchids, a giant snapping turtle, darting fish, a family of loons, and a world buzzing with life.

Protected wetlands like the Big Bay Lagoon on Madeline Island are essential habitat for bitterns and much more. Photo by Emily Stone.

Dragon's Mouth Orchids were a neat find!

This giant snapper just rested on the bottom while we paddled past...

When life is buzzing, Kevin wears his full bug armor!

Emily’s third book, Natural Connections3: A Web Endlessly Woven, is available to purchase at www.cablemuseum.org/books and at your local independent bookstore, too.

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Summer Calendar is open for registration! The Museum’s new exhibit, The Wetland Way is now open! Discover how life thrives at the intersection of soil and water, and why we must care for these special places as they care for us. Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

Heartbeats and Birds

The bird that Jim placed in my hand barely felt like anything against my skin. The black-and-white-striped feathers were soft, their temperature similar to my own. We’d just recorded the weight of this little beauty at 10 grams, or about as much as two teaspoons of sugar. I marveled at their racing heartbeat—more like a vibration than a pulse I could count.

With the black-and-white warbler’s fragile neck cradled between the first two fingers of my left hand, I tipped him down in a pose that most birds find hypnotic. His legs’ wiry strength pressed into the soft pads of my thumb and forefinger. The metal band with a unique number that Jim had just applied to the bird’s left leg glinted in the morning sun.

Master Bird Bander Jim Bryce holds a black-and-white warbler captured in a mist net in the Moquah Barrens. Photo by Emily Stone.

I felt gratitude for this bird’s brief connection to my life and their permanent contribution to research. Then I loosened my grip. Tiny toes pricked my finger as he clung upside down for a second before darting into the brush. I chuckled at the way, even while captive, this black-and-white warbler lived up to their reputation as a nuthatch mimic who is usually seen creeping nimbly along branches on the hunt for insects in the bark.

I’ve been watching Jim Bryce, a Master Bird Bander with a lifetime of experience, band birds on this hilltop in the Moquah Barrens in northern Bayfield County, Wis. for 13 years. Each year I revel in Jim’s steady stream of quiet words explaining the banding process and sharing his vast experience with bird banding over several decades and several government agencies. Usually, I lead a group of 20 Wisconsin Master Naturalist students on a hike up the overgrown footpath from the sandy forest road. We burst into a small clearing to find Jim already set up with his ancient folding table, folding chair, and banding supplies ready to begin teaching the moment anyone is close enough to listen.

Jim at his banding table during the 2016 Wisconsin Master Naturalist volunteer training. You can see the fringe of red pines in the distance. The site has been burned just that spring. Photo by Emily Stone.

This year was different. Rain kept us from banding with the students earlier in the week. But Jim still needed to conduct the banding as part a long-term research project studying how bird diversity changes in response to prescribed burning in this pine savannah. (Read about what we found in 2020.)

Catching the black-and-white warbler was a bit of a surprise. They are lovers of forests, but the lone pine tree on this hill died in the last prescribed burn—seven years ago. Now only a fringe of red pine trees looms in the distance as breezes rustle leaves in an aspen grove across the road. Bad luck with fire weather has prevented burning on the planned three-to-five-year schedule, and not-so-scrubby oaks whacked our faces and waved above our heads as Jim and I visited each of the three mist nets we set up in order to gently entangle the local songbirds.

The 12-meter mist net is visible down the center of the group as Jim extracts a bird in 2016.
Photo by Emily Stone.

Our first net check of the morning had yielded this black-and-white warbler, a beautiful male chestnut-sided warbler, a feisty female rose-breasted grosbeak, and a veery. Veeries are small, brown thrushes also described as forest birds, but their flute-like, downward spiraling song has been a consistent part of our Barrens soundtrack anyway. Jim let me weigh each of the first three birds inside their mesh collection bags and then observe his banding technique. By the time we got to the veery, he insisted it was my turn.

Veeries are small, brown thrushes whose flute-like, downward spiraling song is often heard in damp forests of the Northwoods. Photo by Emily Stone.

My heart raced as I reached my hand into the bag. What if I broke them? What if I let them escape? Then my fingers found a familiar grip, and before I knew it, I was holding this bird just like I had the warbler. Now that I was the bander and not just the releaser, the vibration of their heart felt different. Their safety was in my hands. My own heart slowed, and I took a steadying breath.

We’d already recorded the band number, date, time, location, numerical species code, and weight of the bird-plus-the-bag in Jim’s well-worn notebook. As I held the veery in my left hand, I used my right hand to spread open the tiny, officially issued aluminum band using the split peg on Jim’s banding pliers. Maneuvering the veery so that I could grip their right leg in my left thumb and forefinger, I slipped the open band over their leg. I wielded the power of the pliers as gently as I could to squeeze the band closed, the edges meeting smoothly and the whole thing sliding freely between their foot and “knee.” Now even if the bird escaped, they were ready to contribute to science!

I was too focused on banding the veery to take photos, but later we caught this white-throated sparrow and I was able to band him, too. The banding notebook and supplies can be seen in the background. Photo by Emily Stone.

Male and female veeries look very similar, so to determine the bird’s sex, I blew on their stomach to part the feathers. In female birds, this reveals a featherless area called a brood patch where bare skin conducts heat directly to her eggs. Instead, I found a small knob known as a cloacal protuberance. This organ swells during breeding season and assists a male with fertilizing the female during a brief act called a “cloacal kiss.”

Jim blows on the belly of a male chestnut-sided warbler revealing the cloacal protuberance. Photo by Emily Stone.

Up higher, my breath revealed red skin around their bird’s wishbone, indicating a complete lack of subcutaneous fat. Breeding birds have no time to gain weight! Their body size is more stable, though, so I also measured from the tip of the longest feather to the bend in the wing. All of these data are useful in tracking changes in bird populations over time, but the holy grails of bird banding are returns. Re-catching a previously banded bird is rare in the banding world, but returns provide a wealth of information. (Read about the return we have in 2015!)

From these recaptured birds, scientists have learned about the incredible 24,000 mile round-trip migration that Arctic terns complete each year; the wintering habitat of Bicknell’s thrushes; and the maximum known age for a wild bald eagle (at least 38 years). However, only about 1% of small birds are ever caught again. If someone recaptures this veery, the USGS will notify Jim, and he will tell me.

“This bird will be forever connected to you,” Jim reminded me after we’d sent the veery flying back into the brush. My heart fluttered happily.

The veery and me--my first ever banded bird!