Nighthawks Nesting

Evening light bathed the scrubby, rolling hills of the Moquah Barrens in gold. Eastern towhees and alder flycatchers called from the tallest shrubs and charred skeletons of trees. And every time the breeze calmed, the black flies swarmed. 

But when the breeze returned, the black flies retreated. So I followed my camera up and down the road for several happy minutes, until a truck with a pop-up camper rumbled over the hill in a cloud of dust. The sight of Jim Bryce’s smile through the windshield was enough to put a smile on my face, too. Being alone in nature is lovely, but sharing it with a kindred spirit is even nicer.

Hand-over-hand, Jim pulled a bundle of long metal poles out of the tailgate. Then came a bundle of wooden signs, and a lumpy plastic bag full of nets. We each took an armful. Earlier I’d found a year-old strand of blue flagging on the roadside. We re-hung it on a hazel twig and crashed uphill through the brush on a barely discernible trail, chatting all the way about the work that lay ahead. 

Jim Bryce is a retired forester who has banded birds for several federal agencies. This is the sixth June that he’s set up three mist nets on a certain hillside in the Moquah Barrens on the Bayfield Peninsula. He’s keeping track of how the birds fluctuate in relation to the prescribed burns that the Forest Service is using to restore this habitat. 

Jim Bryce has been banding birds for several decades.

As we located the flagged net sites, raised the poles, untangled the nets, and posted signs declaring this a legitimate research project, Jim kept up his usual constant stream of explanations and anecdotes about bird banding. The third and final site caused us some consternation with a twisted net, so the once-vivid sunset was deepening to purple by the time we closed the net and gathered up our tools for the hike down. Then, from the dusky sky came a distinctive “peent.” 

Jim finished closing up the third net just as darkness falls. 

Of course our heads snapped around toward the sound, and we easily spotted the source: two medium-sized birds danced against the deep blue sky, their long, tapered wings marked by blazes of white across the wrists. 

Photo by Gary L. Clark.

Common nighthawks eat flying insects by expanding their tiny beaks into cavernous mouths and darting through swarms. At flight speeds of 12-35 miles per hour, the insects that enter their mouths go straight down the hatch and meet their demise in a pool of digestive juices. These owl relatives find insects through sight alone, and so don’t actually forage at night, but are most active around dusk and dawn. On the ground, nighthawks’ weak beaks and tiny feet prevent them from feeding at all. 

Suddenly, their normal, plaintive, peent calls were interrupted by a soft roar, like the sound of a racecar zooming past. This “booming” is part of the male’s mating and territorial display. The sound is created when air rushes through the tips of his feathers at the bottom of a dive, and it sent shivers down my spine. 

In the bright sunshine of the next morning, those memories faded from my thoughts. Jim led a group of Master Naturalists from net to net, hoping to catch one last little songbird before the program ended. Between the second and third nets, the participants at the front of the group exclaimed as a nighthawk burst up from the brush. After some searching, we found her nest. In the center of a bare spot, lined only by black ashes from the last burn, sat two eggs, mottled heavily with gray and brown spots.

“That’s it?” Several people exclaimed about the austerity of her nest. Ground nesting birds are especially vulnerable to predators, but the nest’s simplicity is part of their strategy to avoid discovery. The spots on the eggs were remarkably similar to the texture of the ash, and there’s some evidence that she may have chosen the nest site to match her eggs. 

As our attention turned away from the eggs, we spotted the female nighthawk in a nearby tree. Her mottled brown body was positioned along the branch, using both shape and color for camouflage. She would have been invisible to our eyes on the ground, and invisible to the nose of a coyote or skunk, too, since the oil she uses to preen her feathers becomes odorless during the nesting season. 

While the male rarely incubates eggs, he will eventually help with feeding the young regurgitated insects at dawn and dusk. Within the first two days, the chicks double in size, and by day 18 they will make their first flight. 

If this seems like a vulnerable way to live, you’re right. Common nighthawk numbers are in steep decline—falling by 61% from 1966 to 2014 worldwide. In Saskatchewan, scientists found that the decrease in numbers coincided with the spraying of pesticides for mosquito control. Even if a pesticide doesn’t kill birds directly, removing their food source is just as effective. This is likely a major part of their demise across all of North America.  

As I sit at home, days later, this information gives me a new perspective on the black fly bite that still itches on my neck. Folks here in the Northwoods often imagine how wonderful our world would be without the swarms of annoying insects that mar our short summers, but we usually don’t imagine the full set of consequences that wish would bring. I’m happy to put on a head net, suit up in long sleeves and long pants, and use a little bug repellent if it means that nighthawks can go on peenting and booming; their white wrists flashing against a purple evening sky. 

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books. Or order it from our friends at redberybooks.com to receive free shipping!

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum is currently closed due to COVID-19, but we're still building our new exhibit and bringing you educational content. Connect with us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

Brown-headed Cowbirds and Bison

(I recently received a photo a of cowbird egg in a red-eyed vireo nest, so I’m re-sharing this article from 2018—written when I was on my way to Alaska!)

My hike on the Centennial Trail in Wind Cave National Park in western South Dakota had been wonderful. I felt like Laura Ingalls Wilder as I strolled over the rolling prairie hills, dodged buffalo chips on the trail, and photographed wildflowers taking advantage of spring. Thankfully, the hot sun was offset by a cooling breeze. 

Twice the trail ran right through the center of prairie dog towns. Their alarm calls were incessant and pushed before me in a wave, with the closest little rodents chattering from out of sight inside the entrance to their burrow. The bell-like tones of meadowlark calls rang out across the prairie, and repeatedly I searched for the vocalists who sounded much closer than their actual perch. The volume of their songs was impressive. 

The prairie’s wide open horizon seems to encourage restlessness. Back at my car, I quickly settled in for an afternoon of driving west. Pa Ingalls would have understood the feeling. 

I didn’t get very far, though. Where the park road met the highway, a pair of bison grazed on the shoulder. If it was just those two great, shaggy beasts, I might not have stopped, but around their heads fluttered personal flocks of brown-headed cowbirds. The shiny black birds, with namesake brown heads, pecked at the ground right in front of the bisons’ giant heads, played leapfrog over their humped backs, and generally acted just like brown-headed cowbirds are supposed to act. Glad that no one was with me to roll their eyes at my excitement, I swung onto the shoulder, rolled down a window, and picked up my camera from the passenger seat. 

Now, brown-headed cowbirds are not my favorite animals. My parents and naturalist friends have always given them the evil eye. Arthur Cleveland Bent (an acclaimed ornithologist of the early 1900s) called the cowbird a “shiftless vagabond and imposter.” Its scientific name, Moluthrus ater, means “dark greedy beggar.” While they are native to the Great Plains, they have a bad reputation as lazy villains who parasitize the nests of more praise-worthy songbirds. 

Female brown-headed cowbirds lay their eggs in the nests of smaller birds and let other parents do the hard work of feeding their hungry chicks. Cowbird eggs hatch first, and their chicks grow faster than the others. By virtue of being the tallest mouth in the nest, the cowbird babies get more food. Their gain is another’s loss, and their success comes at the expense of one or more of the host mother’s own young. 

While most birds don’t seem to recognize the cowbird eggs or chicks as alien invaders, some do. House wrens puncture cowbird eggs. Yellow warblers build a new nest right on top of the invaded one—smothering their own eggs as well. Robins, catbirds, and a few other birds with big beaks toss out the strange eggs. I feel like giving them all a high-five for not being duped. 

But on a birding walk last spring with Laura Erickson—a wonderful Duluth-based birder, author, educator and scientist—I gained a whole new perspective on the cowbirds’ predicament.

These maligned birds once depended on the bison’s feeding to flush tasty insects, and on their heavy hooves to break up tough prairie sod, which made seeds available despite the birds’ scrawny feet. The problem was that bison herds moved regularly, and the birds had to follow. That transient lifestyle wasn’t conducive to settling down and raising a family. The cowbirds’ only option was to deposit their eggs in the nests of birds who could find food even without the bison, and hope for the best. 

Hope isn’t their only strategy. A female cowbird lays about one thick-shelled egg each morning, and can lay forty or even sixty eggs in a season. Using radio-tagged birds, scientists discovered that females will spend the morning in nest-rich habitats like forests and edges. They may silently observe potential hosts in preparation for a “mission impossible”-style egg laying operation; walk around in dense ground cover looking for nests; or fly noisily through the shrubs hoping to flush a mother and home in on a target. They spend their afternoons foraging in more open habitats. Sometimes they’ll even return to a parasitized nest to check on and feed their own young. Once fledged, the young cowbirds instinctively seek flocks of their own kind. 

This worked out pretty well when there were still plenty of bison moving freely across the plains. Nomadic cowbirds rarely parasitized the same nest repeatedly, so their songbird hosts recovered easily from the reproductive setback. The problems came when pioneers settled the plains and replaced nomadic bison with fenced cattle, tilled farmland, and backyard feeders. The birds adapted well to the new scheme, which allowed them to spread east into new territory, where songbirds weren’t used to their skullduggery—which could now be concentrated instead of scattered. Their success came at the expense of their reputation, though, and cowbirds are now an unwelcome visitor in backyards from California to Maine. 

Is it really their fault? Like so many animals, they evolved to live in a world that we have changed almost beyond recognition. But there, on the side of the road surrounded by vast prairies and restored herds, they were behaving exactly like they should. They still aren’t my favorite birds, but for just a moment I could really appreciate the cowbirds’ place in the world. 

Then—restless as ever—the two bison moved on. I put down my camera, rolled up the window, and continued west. 

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books. Or order it from our friends at redberybooks.com to receive free shipping!

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum is currently closed due to COVID-19, but we're still building our new exhibit and bringing you educational content. Connect with us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

Bad Bugs and Bangs

With a bike helmet squashed over my unusually bushy hair (it hasn’t been this long since 2009!) I started to open the door. The bright orange of my bike panier caught my eye, and I hesitated only a second before dropping my camera in and taking it with me. Racing like a NASCAR driver—mosquitoes swarming viciously—I mounted my bike and launched down the driveway. After a shrug of my shoulders to dislodge the hangers-on, I was bug-free and enjoying a cool evening breeze of my own making.

Ten minutes later the mosquitoes swarmed again as I pulled over where the loon nest becomes visible through the shoreline vegetation. A couple of weeks ago, I wrote about the scourge of black flies that drove this loon pair off of their nest—leaving two eggs behind to fail. Since then, Walter Piper has reported on his Loon Project blog that up to 80% of loon nests in the area were abandoned in early to mid-May; all or mostly due to the clouds of loon-specific black flies who hung around longer than usual due to our cool spring weather. That makes this spring’s black fly outbreak even worse than the one we had in 2014, when 70% of first nesting attempts were aborted. 

Even through my dusty sunglasses, I could see the distinct silhouette of a loon on the nest. Yes! With the help of my camera’s zoom, I discovered that she wasn’t just sitting there. The loon on the nest was actively reaching out with her beak and pulling more nesting materials up toward her. 

I say “her” because nest building is one of the few activities that can tell us if a loon is male or female. They look exactly alike, and even though males tend to be larger, on average, that’s neither easy to see nor completely reliable. In their remarkably egalitarian relationship, loon parents share incubation and childcare duties 50-50. However, there are a few divisions of labor based on sex. 

Male loons pick the nest site. This place-based responsibility is one reason that they are so tied to a specific territory and will return to it year after year. Males also give the wildly fierce yodel call to defend their territory. Female loons build the nest, and for obvious reasons, lay the eggs. So, I feel that I can safely call the loon who is adding materials to the nest “her.”

A few days later I returned to the nest again, and found one loon incubating calmly, while the other preened and stretched nearby. This is a very good sign. 

Loons all over the Northwoods have returned to their nests for a second attempt—now that the black flies have died down. They remain vulnerable to many other types of disturbance. Photo by Emily Stone.

While I’m glad that they’ve managed a second nesting attempt, I’m still worried for this expectant couple. Their nest is low to the water, and near a busy boat landing. The heavy boat traffic we’re seeing up here already this summer can result in boat wakes that wash eggs out of the nest, nervous parents that leave the nest for their own safety, and an increased danger of a loon swallowing a sinker or lead jig and dying of lead poisoning. 

Bugs, lead, and boat wakes are not the only threats to loons. Marge Gibson, Executive Director of the Raptor Education Group, Inc. (REGI) wildlife rehab center in Antigo, Wisconsin, has many horror stories about birds and other wildlife injured during fireworks displays. Loons are just hatching around July 4, and loud noises can startle them. Even more devastating is when people throw fireworks into the lake itself, to cause an underwater explosion. The reverberations from that can deafen a swimming loon. Marge has found both adult and juvenile loons scooting on their bellies (they can’t really walk on land) far into the woods because they were so frightened on the lake. 

Loon chicks hatch right around July 4th, and fireworks—especially those thrown directly into the water—can send them scooting awkwardly, and dangerously, into the woods. Photo by Emily Stone. 

Loons aren’t the only iconic Northwoods species impacted by fireworks. “Young eagles start to fledge right around July 4,” she continued. “They are often teetering on the side of nest, not quite ready to fly. A nearby explosion from fireworks can cause them to leave the nest prematurely, and at night.” There’s a high chance they’ll collide with something in the dark, or fall to the ground and be injured. Every year REGI receives young eagles with broken wings and other injuries as a result of fireworks. Some don’t survive. 

This juvenile bald eagle is at a vulnerable stage. Loud fireworks nearby could send him crashing out of the nest before he’s truly ready. Photo by Emily Stone. 

Longer-term issues are caused by the carcinogenic elements (the ones that make cool colors when they burn) that fireworks add to our lakes, and the litter of plastic casings that can sneak into the food chain, causing malnutrition problems. 

This year’s unique situation, with some people limiting their contact with people outside of their household, and others eager to gather in groups, means that Marge is more worried than ever about an increased number of individual fireworks having impacts on wildlife. “The Northwoods aren’t an amusement park,” she explained. “It’s a different habitat up here, with lots of sensitive species that nest low and on the ground. Residents and visitors alike need to respect it and treat it with care.”

That doesn’t mean skipping fireworks altogether, though. Just stick to the small stuff—like sparklers—at home, and save the big fireworks for municipal displays that have safety measures in place, impact limited areas for a limited time, and entertain a lot of people all at once. Essentially, they have more bang for their buck. The big fireworks are illegal for private use in most places anyway, although the laws and ordinances are not well enforced. 

“Destroying wildlife, and especially killing eagles, on the Fourth of the July just doesn’t seem American!” said Marge. With a little bit of consideration for species other than our own, Independence Day can be fun for humans and less harmful to our national emblem.  

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books. Or order it from our friends at redberybooks.com to receive free shipping!

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum is currently closed due to COVID-19, but we're still building our new exhibit and bringing you educational content. Connect with us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.

Community Science and a Quest for Salamander Eggs

I’ve never been so glad to reach the top of St. Peter’s Dome. Even under heavy gray skies, the view from its high, rocky outcrop was spectacular. A forested mosaic in shades of green stretched all the way north to the shimmering strip of Chequamegon Bay on Lake Superior. Hiking up, the tree canopy felt closed. But from above, the fuzzy white of emerging bigtooth aspen and the reddish tinge of young oak leaves hinted at a more precise phenology. Despite our recent warm days, it’s not quite summer. 

Can you spot Lake Superior? It's that lighter band below the far hill...

It is, however, full-on bug season. I didn’t race to the top because of the view; I was chased there while seeking a stiff breeze and refuge from the biting hordes. I don’t hike much after the mosquitoes hatch, but on this day I had a special mission that was worth the blood loss.

It all started a few weeks ago, when I received an email from Jon Davenport, a biology professor at Appalachian State University in North Carolina. He and his students are studying the geographic variation in how spotted salamanders respond to pond drying during their larval stage. In a nutshell, do salamander babies in Louisiana grow faster as their pond gets shallower? How about in South Carolina? Massachusetts? What about in Wisconsin? 

The students collected eggs in the southern part of spotted salamander’s habitat earlier this spring. Then, the pandemic hit. Their plan for a road trip to Wisconsin to sample spotted salamander eggs at the northwest limit of their range was derailed. Jon got creative, and searched the iNaturalist database. I’ve written about this awesome resource previously—people post photos of plants and animals, other people confirm the identification, and then the observations are available for anyone to look at, including scientists. I’d posted a photo of spotted salamander eggs in 2016. And now here I was, on St. Peter’s Dome, with a backpack full of zip-top baggies and dozens of swelling mosquito bites. 

Spotted salamander range map. Why don't they go farther west???

https://amphibiaweb.org/cgi/amphib_query?where-genus=Ambystoma&where-species=maculatum&account=mol

Facing into the wind, I unfolded my BugJacket—still with its factory creases—and slipped this hooded shirt made of mosquito netting over my head. A sense of peace and goodwill descended with it. I bought the jacket for my sabbatical to Alaska and never needed it. Within 30 seconds of use on this day, it became an essential part of my hiking gear. 

The BugJacket is a game changer! So much better than a head net (I wore a head net on the way up and it kept gaping and letting bugs inside...) Mine is Sea to Summit brand, but there are others available...

Now, having suited up, I abandoned the delicious breeze and began to hike down. Just below the summit is an old road bed, and off to its side is a small, round pool. Peering through the shimmering reflections of trees, I scanned the dark water for salamander eggs. Almost immediately, I caught site of one cluster; the dozens of embryos shimmering like pearls in their clutch of clear gel. 

Three more clusters appeared nearby, and with my search image primed, I walked slowly around the pond, spotting two more groups of egg masses. Most of the eggs were visibly green. Salamanders have a symbiotic relationship with algae. As with plants and animals everywhere, the two organisms exchange carbon dioxide, oxygen, and nitrogen to their mutual benefit.

That little black spot with a tail near the salamander eggs is a wood frog tadpole. These two amphibians breed in the same pools, but wood frogs develop faster. The wood frogs also EAT the salamander eggs. Actually, according to Jon, EVERYTHING eats the salamander eggs and larvae, and it's amazing that they survive at all, and are common. Since they live so long as adults, and lay so many eggs, they only need one or two good years in their whole lifetime in order to help the species persist.

Over the course of 70 to 130 days, these eggs will hatch into tadpole-like larvae with an elaborately plumed collar of gills, and then lose those gills and leave the water as juvenile salamanders. They’ll seek winter refuge below the frost line, and return to breed in the same pond every spring for the next two-to-three decades. 

The water was cool and the bottom of the pool slippery with leaves as I waded in up to my shins. Gently, I scooped one egg mass into each of four plastic baggies. Feeling their fragility, I was glad that I’d resisted the temptation to douse myself in bug spray that might have seeped through their porous protections. I double-bagged each one, and inflated the outer bags with air before sliding them gently into my backpack for the return journey. 

Check out my highly scientific tools: ZipLock baggies leftover from Christmas...special edition with the Nutcracker!

Back at the parking lot, I arranged the four bags of eggs in a cooler, and padded them with bubble wrap. After taping on the cooler lid, I slid it into a cardboard box already equipped with a shipping label. Destination: North Carolina. The sun came out during my drive up to Ashland, and I got a close-up view of the water I’d seen from the top of the dome. Once the clerk at the service counter scanned the label, my job was done.

The box will arrive at Jon’s house in a day or two, and these eggs will join the experiment already in progress. In a modified walk-in cooler set to about 67 degrees F, with 12 hour day-night cycles, he’ll place four freshly hatched larvae in each of 12 five-gallon buckets. Strategically, he and the staff at the university’s animal research facility will remove water so that a third of the buckets will go dry after 60 days, a third will go dry after 80 days, and the rest will remain wet for 120 days. What the salamanders do is reliant on the genetic codes inherited from their parents. Some salamander larvae grow faster toward terrestrial, lung-breathing adulthood as their pond shrinks. Preliminary results show that the ones from Louisiana don’t. 

Here's one of the buckets with some salamander tadpoles hiding in the leaves. I heard from Jon, and my eggs arrived safely! They haven't hatched yet...but will soon. 

The students call this project "The Bucket Experiment" because...well...it's all 5 gallon buckets. The nice thing about salamanders is that they are adapted to survive in small, stagnant pools, so don't require elaborate water filtration and oxygenation systems. And look at all of those buckets the'll have to reuse in the future! So useful!

Why does it matter? This is a baseline study, asking basic questions about salamander ecology. How do they interact with their environment? Next fall, Jon’s students will analyze the data, and begin to hypothesize again. What happens if climate change makes the salamanders’ pond dry up faster? Can some populations adapt? What do we do about the populations who can’t? A good research project will raise more questions than it answers. 

In the meantime, Jon is thinking ahead. This adventure in community science and “remote sampling” has been fun for both of us, and easier on Jon’s budget, too. Maybe, with the increase in telecommuting, virtual events, and video meetings, scientific field research will shift toward remote work, too. 

Now that I’ve discovered the BugJacket, I’m excited and ready to help! 

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books. Or order it from our friends at redberybooks.com to receive free shipping!

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. The Museum is currently closed due to COVID-19, but we're still building our new exhibit and bringing you educational content. Connect with us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.