The Sparrow’s Songs

A faint string of birdsong filtered through closed windows on a recent morning. It was well after dawn, but thick gray clouds made it feel like the Sun had yet to rise. “Song sparrow!” I exclaimed. “They must have arrived overnight!”

My friend, who started birding last summer, looked skeptical. “That doesn’t sound like what I remember.” He pulled out his phone and opened the Merlin Bird ID app from the Cornell Lab of Ornithology to play an example of a song sparrow’s song. The recording started with a pair of notes and then a couple more, and then devolved into a messy, buzzy trill. Outside, the bird sang with the same quality, but not exactly the same pattern.

Listen Here: https://www.allaboutbirds.org/guide/Song_Sparrow/sounds

Back in my college field ornithology class, we’d been taught the mnemonic “Maids! Maids! Maids! Put on your teakettle-ettle-ettle.” The maids representing the first notes, and the tea kettle mimicking the trill. It helped if we sounded a little like a spoiled heiress when we said it, to match the loud, brassy tone of the sparrow.

While the funny mnemonics I learned in that class were helpful, they were useless without also noticing variations in tone quality of the birdsongs. Repetition was also key. Before quiz days, we’d all sit around a tape player and listen intently to the mixtape our teaching assistant had made for us.

With song sparrows, the repetition came naturally. They are one of the first birds to return in spring. They are quite common around lakeshores, marshes, road edges, fencerows, yards, and pretty much anywhere there are some bushes and some grass. And they live up to their name, Melospiza melodia, which means “melodious singing sparrow.” One male was observed singing for 10 hours in a single day, which meant completing 2,305 songs.

With brown, white, and gray stripes on their head and breast, song sparrows resemble many sparrows who are brown and stripey, and somewhat hard to tell apart. The pattern I look for is a particularly dark spot under their chin where their chest stripes meet up. My TA taught me to remember this like the bow tie on an opera singer.

Photo by Emily Stone.

I was quite familiar with song sparrows by the time I moved from the Midwest to California in 2007, but I remember the experience of confusion the first time I heard one there. The song that emanated from a shrub in the coastal grassland of Salt Point State Park wasn’t the pattern I remembered, but the tone was the same, and my binoculars revealed the black bow tie.

California coast. Photo by Tom Fitz

As it turns out, song sparrows are widespread, and well-known to have regional accents. The variation is likely a result of picky females, who prefer to mate with males who demonstrate an ability to learn new song components from other males.

I guessed that the odd-sounding song sparrow outside the window on that gray morning was on migration to somewhere else, somewhere his accent would fit in. I also guessed that he’d been part of a larger wave of migrating birds who’d sailed in on a south wind overnight. Hoping that the rain would hold off, we headed out to Artist’s Point in Grand Marais, MN, where Lake Superior concentrates birds who’d rather not cross the open water.

Song sparrows were the first thing we heard from the parking lot, and we followed their melodies to a thicket of willows and red-osier dogwood. One sparrow swooped away with a characteristic tail-bobbing flight, landed in the top of a small tree, and belted out a few songs. Before long, though, he swooped back into the brush to join his buddies scavenging for seeds on the ground. With competing needs to refuel for the next leg of migration and to satisfy their raging hormones, the guys sang even from the middle of the thicket.

Cameras poised for the moment a sparrow posed for a clear photo, we spent several minutes there, just observing. That’s nothing compared to what Margaret Morse Nice did on May 11, 1935. On that day, she followed a single song sparrow from midnight to midnight, recording his behavior for 24 hours straight. She’s the one who observed him singing 2,305 complete songs for a total of 10 hours—which was more time than he spent roosting (9 hours) or feeding (5 hours).

That birdwatching marathon was part of an eight-year study in which Nice, both a trained zoologist and mother of five, trapped, marked, and observed 870 different song sparrows in her Ohio backyard. Before her groundbreaking work, many bird books contained “facts” conjured up by Aristotle, and the study of birds focused on “collecting” them—with shotguns.

Nice banded her birds with plastic from children’s toys and created a new standard for scientific research by observing hundreds of marked individuals over many years. In her studies, she learned to recognize individual males by their distinctive songs and pick out the phrases they’d learned from their neighbors. Her work inspired a new generation of ornithologists—and me—to be more observant.

Margaret Morse Nice lying flat in the grass to study a nest of baby field sparrows.
Photo taken by Al Fenn circa 1956

Emily’s award-winning second book, Natural Connections: Dreaming of an Elfin Skimmer, 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 is closed for construction until May 1. Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

The Pulse of a Waking Forest

Our morning dawned crisp and blue. In the woods, we knew that the trails would be firmly frozen, the mosquitoes still far from flying, and perhaps the ticks would be hunkered down, too. This chilly spring weather is a perfect match for a hike on the North Country Trail.

As we entered the brushy, deciduous forest and strode down the leaf-littered path, I felt my heart quicken and thud in my chest. After a moment, the sensation reached my ears, too. It wasn’t my heart—it was the drumming of a ruffed grouse! I’m always amazed by how much I feel their sound instead of hearing it. In the thick of mating season, their incessant, accelerating beats have even caused a fleeting catch in my breath as they temporarily overpower my own body rhythms.

Ruffed Grouse displaying. 
Photo by USFWS midwest, Public domain, via Wikimedia Commons

The grouse drummed again; thumping slowly at first, and then crescendoing into a rapid-fire blur. As his last vibrations dissipated into the still air, another grouse answered from a neighboring territory. The low-frequency sounds are audible from up to a quarter mile away.

Over the years, we’ve employed several explanations of how ruffed grouse create this sound. Because male grouse often display from atop a hollow log, perhaps they created the sound by actually hitting the log with their wings. Or, since they also display on rocks, mounds of soil, or prominent roots, perhaps the sounds come from the wings striking together behind the birds’ back, like a spruce grouse. Those explanations were discredited in part due to some fuzzy photographs of captive Ruffed Grouse by Professor C.F. Hodge of Clark University in the early 1900s.

H.E. Tuttle spent many days in blinds observing drumming grouse from 1910 to 1918, and published his findings in the American Ornithologists' Union journal, The Auk. Tuttle examined Hodge’s photos and agreed that the sound did not come from wings beating together. He posed the possibility that rudimentary air sacs contribute to the sound (as in the displays of greater sage-grouse).

One theory he dismissed heartily was that the drumming sounds were produced the same way as a grouse’s noisy flight. He described it as “an unsatisfactory explanation of that far-away throbbing challenge which steals on the ear so subtly, like the half heard beating of one’s own heart.”

As in many realms of science, when technology improved, so did our explanations and accuracy. In the 1920s, Arthur Allen of Cornell University used a new-fangled contraption to shoot motion-picture footage of the grouse. By slowing down the movement, he ruled out every explanation except the one that we currently accept.

On the Cornell Lab of Ornithology’s “All About Birds” website today, you can read the result of their founder’s research: “The male Ruffed Grouse’s signature drumming display doesn’t involve drumming on anything but air. As the bird quickly rotates its wings forward and backward, air rushes in beneath the wings creating a miniature vacuum that generates a deep, thumping sound wave...”

That miniature thunderclap sends “the blood sap pulsing quicker along the veins…” (Tuttle again) not only for humans, but also for the lady grouse. She can probably differentiate between different males, since the number and rate of pulses in each bout of drumming is unique to each individual.

Tuttle noted that if he rustled the leaves in his blind to sound like the dainty footsteps of an approaching female grouse, the male would drum instantly, and also flare his name-sake ruff of neck feathers. Once he’s able to attract a female with this huge output of energy, copulation lasts only a few seconds. The female then wanders off to build a ground nest and raise the chicks completely on her own.

Hiking down the trail, we found many clusters of sawdust-filled grouse droppings. Those piles marked where they had digested tree buds and catkins on sub-zero nights while buried snugly in a snowdrift. In one balsam thicket we heard—but did not see—the whirr of a grouse’s startled explosion into flight. We have to admire the tenacity of these year-round residents, even if we sometimes chuckle at their lack of grace.

Grouse scat in snow. Photo by Emily Stone. 

Now, as the days lengthen with the promise of spring, we can also appreciate how grouses’ drumming seems to jump-start the pulse of a waking forest.

Author’s Note: This article was originally published in 2015.

Emily’s award-winning second book, Natural Connections: Dreaming of an Elfin Skimmer, 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 is closed for construction until May 1. Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

Snowshoe Hares Eat Dirt

“Empty,” called Claire Montgomerie over her shoulder with a hint of relief in her voice. Matt Kynoch and I paused in our crashing through the brush, waited for Claire to make sure the live trap was still properly set, and then we all tromped back along the transect together. “Full,” announced Matt as we approached the next trap, a snowshoe hare cowering inside.

We used live traps baited with carrots and alfalfa cubes to catch hares in the Brooks Range. A piece of tarpaper over the cage provides protection from rain and sun, as well as making the hares feel more secure and hidden. Photo by Emily Stone.

Matt and Claire—both graduate students at the University of Alaska Fairbanks—sprang to action with practiced efficiency. Claire fit a long, white pillowcase around one end of the trap, grasped the door through the fabric, and opened it wide. Matt crouched at the far end and blew little puffs of air on the hare’s rear end to encourage them to run into the bag. Sometimes, cartoon-like, the hare would blast into the bag with such force that you could see the impression of their little face through the fabric.

Matt and Claire spooking a hare into a pillowcase. Photo by Emily Stone.

For three days in the summer of 2018 we worked on this mark-recapture survey along a pipeline access road in the Brooks Range of northern Alaska, gathering data that would help scientists at the nearby Gates of the Arctic National Park estimate hare population numbers for this year. Our opinion? The population was high. Almost every trap was full, which meant a delayed lunch, and that sense of relief to find an empty trap.

While the Dalton Highway is riddled with potholes and washboards for much of its length, but the scenery more than makes up for it. Photo by Emily Stone.

Along one rutted gravel road we set 14 live traps baited with alfalfa cubes and carrots. Claire pointed out exposed dirt on the road cuts where hares had been recorded coming to lick the soil. National Park Service scientist Donna DiFolco had asked us to help recapture hares who had been previously deployed with GPS collars to track their use of the mineral licks.

Later in the week we collected data for Claire’s master’s thesis. From each hare, they plucked fluffy tufts of hair, clipped a toenail, and drew blood from a vein in the hind leg. I also helped collect fresh bunny scat into little plastic bags. Once back in the lab, Claire would run tests on the materials to find signs of the hare’s stress levels and other measures of health. All of this was in the name of science, and Claire is not the first to try and tease out mechanisms behind a roughly 10-year cycle of snowshoe hare population highs and lows.

I was super impressed with Claire's blood drawing and hare handling skills. She trained with a veterinarian on campus. Photo by Emily Stone. 

Releasing the hare. Photo by Emily Stone. 

The classic, top-down, predator-driven theory posits that as hares increase, the number of lynx who feed on them go up, too. Hares get eaten. Lynx have more babies. Soon there are too many lynx and not enough hares to feed them all. The lynx population goes down, hare numbers recover. The cycle starts over. Most scientists now believe that this is oversimplified.

A giant, furry lynx paw. Photo by Emily Stone.

For example, predators don’t just kill hares by eating them. When lynx numbers are high, hares may spend more time being vigilant and less time feeding. Plus, DeAngelis et al, 2015, found that when numerous hares browse heavily on their favorite winter foods, those willow and birch shrubs increase the concentration of anti-herbivory chemicals in their tender new twigs.

Therefore, at the same point in the cycle when hares experience the most stress from high numbers of predators, they are left eating woodier and more toxic twigs. That leads to lower survival and reproduction—except for those hares who were coming to lick the soil.

The interconnected boom-and-bust lifecycles of lynx (bars) and snowshoe hare (line) populations in the central Brooks Range. Lynx data are from the Alaska Department of Fish and Game lynx sealing records, and snowshoe hare track counts are from this study.

NPS / Donna DiFolco   https://home.nps.gov/articles/000/brooks-range-snowshoe-hares.htm 

When I tell people about my 2018 sabbatical to Alaska, this snowshoe hare study is always a highlight. Which is why I was so excited to see a recent headline from the National Park Service during my lunch hour last week. After decades of research, Donna DiFolco, the NPS scientist who Claire was assisting with the mineral lick study, confirmed what locals had already observed: in areas with mineral licks, the hare population grows larger for longer. Instead of peaking equally every 10 years, the hares with access to natural mineral licks have a super peak every 20 years, and a smaller one in between.

By comparing the samples of hare scat—some of which I helped collect!—Donna was able to determine that mineral licks were providing critical nutrients like sodium, calcium, potassium, and magnesium that helped the hares to stay healthy even when the plants they ate became more toxic. Donna retired last year, but her colleagues will continue to investigate the importance of mineral licks for other mammals, too.

Hare scat. Photo by Emily Stone. 

The data I helped collect from hares in the summer of 2018 contributed to Claire’s master’s thesis and an article published in The Scientific Naturalist. Photo by Emily Stone.

All those years ago, while Clarie, Matt and I were staving off hanger to trap all the hares, I commented to them that 2018 was surely a peak year. Like good scientists, they equivocated. That could only be determined in hindsight. Well, according to Donna’s data, the super peak was still one year away—in 2019. If I’d have been part of the research team that year, I might have had to join the hares in eating dirt!

Author's Note: Portions of this article are republished from 2018. Check out the three original articles on the blog to find out more about how the moon may impact the hare's cycles, too!

Emily’s award-winning second book, Natural Connections: Dreaming of an Elfin Skimmer, 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 is closed for construction until May 1. Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

A Home for Wood Ducks

The sun was setting on a warm afternoon by the time I arrived home. Although the lake was still frozen, and there were several inches of snow in the forecast, I took advantage of temporarily bare, dry trails for a short walk.

Soggy leaves and green moss were my most interesting observations until I emerged into the clearing around what will soon be a frog pond. Ice still locked up the tangle of alder stems in the center of the pond, but black water reflected twiggy treetops around the margin.

As I approached, an explosion of sound and movement from the far side made me smile and think of Christmas. That’s an odd association for early spring, but the rising woooo-eeek calls of wood ducks have always reminded me of the sound that scissors make when I run them along the red and green curling ribbon while wrapping presents. The shimmering green head and other bright colors on the male wood duck reinforce that association for me.

Male wood ducks provide a beautiful splash of color when they return in early spring. Photo by Tom Koerner, USFWS, Public Domain.

But listening to a pair of wood ducks explode from a tiny patch of open water in a woodland pond and woo-eek through the woods is a distinctly springtime experience. Wood ducks are uniquely adapted for life in the forest, with strong claws on their webbed toes that allow them to perch on tree branches. Their short, narrow bill is adapted to picking up acorns and other seeds—which their gizzard can grind up—and foraging for the starchy bulbs of wetland plants. They also eat plenty of aquatic insects, especially when young.

Wood duck drake in a woodland pond, Mike Budd, USFWS, Public Domain.

Scaring up a pair of wood ducks together is common, because these ducks find a mate on their wintering grounds and arrive home together. The male sticks around until all the eggs are laid and then takes off. In the southern part of U.S., that might happen in February, but up here, nesting can take place through June.

As far as I know, I’ve never had a pair of wood ducks nest near this little frog pond, but their cavity nests are not always easy to find. They usually choose a tree more than 2 feet in diameter, with a hole where a broken branch fell off and heart rot excavated a cozy space.

Once a nest cavity is chosen, the female will lay one egg per day for 6 to 15 days, and then, once they are all ready, she begins incubating them. This synchronizes development within the eggs so that the chicks hatch at about the same time. After just a day in the nest, the chicks are ready for action. They use their clawed toes to climb up the inside of the nest cavity, then perch with trepidation on the rim for their first view of the big, wide world. You’ve probably seen videos of the downy fluffballs bravely leaping out of their nest cavity and windmilling tiny wing nubbins on their 60-foot fall to the ground. Ideally, Mom and Dad will have chosen a nest with a water landing, but soft leaf litter works fine, too.

In some cases, 20, 30, or 40 chicks may emerge from a single nest! It’s not possible for all of those chicks to belong to one female, they are a result of egg dumping. Sometimes a female wood duck who couldn’t find a cavity of her own, or lost her nest to a predator or in a storm, or who is young and inexperienced may lay her eggs in the nest of another wood duck. Sometimes a duck with her own nest will spread some eggs around to hedge against failure in her own nest.

Sometimes wood duck females will dump extra eggs into the nest of another female. This can result in surprisingly large broods of chicks. This happens more often in nest boxes that are highly visible and close together. Photo by Jim Hudgins, USFWS, Public Domain.

With such specific requirements for a nest cavity, it’s easy to understand why there might not be enough to go around. That’s why many people build and install wood duck nest boxes. You’ve probably seen these big plastic or wooden structures on metal poles or attached to trees over the water. Along with protections against overhunting, these nest boxes have allowed wood duck populations to recover from seriously low numbers in the early 20th century. Habitat protection, and an increase in beaver numbers and beaver ponds also helped with their recovery.

Nest boxes mounted on metal poles replace absent tree cavities and reduce the number of predators who can eat the eggs and chicks, but nest boxes are not without risk. When nest boxes are placed out in the open and close together, egg dumping becomes more common. But one female can’t effectively incubate a whole pile of eggs, and not all may survive. She may even become overwhelmed and just give up, resulting in the loss of a lot of potential reproduction.

Nest boxes that are tucked away and spread out to a more natural density in the habitat are the most valuable for wood duck conservation. And a pair who finds a naturally well-hidden nest cavity is the luckiest of all.

Turning back toward my own house in the gray of evening, I wished my frog pond pair well in their search for a home.



Emily’s award-winning second book, Natural Connections: Dreaming of an Elfin Skimmer, 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 is closed for construction until May 1. Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.