The Musicality of Birdsong

From Donald Kroodsma's The Singing Life of Birds: The Art and Science of Listening to Birdsong, 2005.

From Donald Kroodsma’s The Singing Life of Birds: The Art and Science of Listening to Birdsong.

Formal study of birdsong has long been fascinated with the who, how, and why of some of our most ubiquitous outdoor sounds. Many guides encourage new birders to learn their species by ear, listening for bird presence rather than relying on sight alone. Researchers have examined everything from a songbird’s syrinx (the bird equivalent of a larynx) to its wing morphology to determine how a bird makes its song. Ecologists have monitored bird behavior to suggest why they sing and why birdsong makes us feel happy and safe. (For further thoughts on birdsong as a cultural ecosystem service, take a look at my research proposal on the valuation of birdsong in education.)

As a student of an Applied Wildlife Management course and an avid musician and fiddler, and a complete beginner when it comes to birds, I decided to examine the what of birdsong. More specifically, I was curious about the musical what, the pieces and patterns of sound that make up a spring morning or summer evening. Do birds sing in pitches and tones like we do? Do they prefer certain keys? Do they take a breath with each phrase? And how hard could it be to learn to reproduce birdsongs? (Quite hard, it turns out). Click on the bird names that look like this to hear my renditions of some of these birds’ songs.

Intervals

Western music revolves primarily around a 12-tone scale. Those tones are the 12 keys, both white and black, on the piano between any note and its octave above or below (for example, between a ‘C’ and the ‘C’ above it). Combinations of these tones form intervals that all have specific names: major thirds, perfect fifths, minor sevenths, and so on.

Knowing my intervals, I wondered which ones birds often use. Do those intervals fit within our 12-tone scale? To find answers, I first drifted to the simple song of the chickadee. Its distinctive “Hey Sweetie” is the soundtrack of our Vermont winter days and the backdrop of so many of our spring and summer bird symphonies. The Black-capped Chickadee (reminder: click on “Chickadee” to hear my rendition of its song) sings in two pitches usually separated by a minor third interval. That’s the interval you’d use to imitate an old-fashioned siren, or the first notes of the children’s song “This Old Man”. Oddly, the chickadee’s song is identical throughout the North American continent except in Martha’s Vineyard, where it sings two mono-tonal “Hey Sweeties”, each separated by a minor third (for more fascinating information on the phenomenon of the uniform chickadee call, check out Donald Kroodsma’s The Singing Life of Birds: The Art and Science of Listening to Birdsong).

But the chickadees aren’t alone. The Common Loon wails its mournful cry by jumping up, then sliding down, a minor third. Its yodel and tremolo revolve around this same interval. The Barred Owl “cooks for you” over a minor third and the Eastern Peewee hops up one minor third, and then another. (Side note: For those with a background in music theory, you may remember that a minor third plus a minor third makes a tri-tone, or the interval halfway between a perfect fourth and perfect fifth. The tri-tone was once called the “Devil’s Interval” and was banned in Renaissance church music. I hate to think how the singing Peewee fared in those days.)

The prevalence of the minor third in birdsong has not yet been well documented nor explained by birders, evolutionists or musicians (read the post of a similarly perplexed author here). Thankfully, birds use many other intervals to make their songs, some of which are musical to human ears. The White-Throated Sparrow (sings its “Oh Sweet (Sweet) Canada Canada Canada Canada” over a perfect fourth (the interval found at the beginning of “Here Comes the Bride”), as do some songs of the Northern Cardinal. The Common Yellow-Throat roughly hits notes within a perfect fifth (here, you only need to think of the beginning of the theme music for “Star Wars”), as does the arpeggio of the Whip-poor-will. But more on those two when we speak next of tempo.

Tempo

Many birdsongs are sporadically sprinkled with a breathy silence that relaxes the human listener, and one would assume, even the bird. But the tonally and rhythmically consistent calls of the Whip-poor-will are different. Sometimes paced around 60-65 calls per minute, its song is like a melodic metronome. Its relentless and rushed beat reminded me of dance club music. Often between 110 and 130 beats per minute, club music is designed to be faster than a slightly elevated human heartbeat, making the listener feel anxious and ready to dance. My impression of the whip-poor-will’s call? Add some beat boxing behind it at double time tempo and you’ve got nature’s recipe for urban groove. I only wonder how long it can go before it takes a breath.

The Common Yellowthroat is also an adept and rhythmic songster. Its call was the only one of my small study that I had to record at a modified and slowed pace. The jagged rhythm of its staccato (meaning, short and clipped) song notes almost disappears when sung at full tempo. The quick speed of some birdsongs makes the task of learning to reproduce them seem daunting at times. Thank goodness for the magic of technology. I tapped into my brother’s transcription company to slow recorded birdsongs down to one-quarter tempo to discern some notes and rhythms of speedy songs.

Some Lessons Learned

The process of learning to reproduce birdsongs on my fiddle taught me as much about my own musical ability as it did of the birds’.

Listening – Even with regular practice, I couldn’t accurately reproduce a birdsong without listening to the original every day. Left to my own devices, I morphed the birdsong into a tonal or rhythmic pattern that was already familiar to me from previous musical exposure. I’ve clearly practiced my acute listening skills more with fiddle tunes than with birdsong. What kind of musician would I be if I had learned to play birdsongs as a child before ever attempting Twinkle Twinkle Little Star?

Vibrato – Or, no vibrato. The warble of many birdsongs does not come from a pulsating, bending pitch change. So far, I’ve found that birds sing pure, unwavering pitches. They just have an ability to switch quickly between different pitches. Vibrato on a fiddle does no justice to birdsong.

Patterns – The patterns of birdsongs and their parts vary by species and within species. They are often not predictable, nor do they fall into patterns common in our own music. Out of habit, I found myself adding familiar grace notes (or, short notes used to decorate a primary note) to dress up a birdsong, only to find myself led away from the true song. Clearly, birds never took tips from Mozart (but I bet that Mozart took tips from them).

The Future of Music and Birdsong

I am not the first to dissect the musicality of birdsong. F. Schuyler Mathews wrote and notated the Field Book of Wild Birds and Their Music in 1904, but I’d imagine that many more birders and musicians had attempted this before in their own interpretive ways. Remembering that birds feel no pressure to sing to a certain standard, I wonder if their songs can change. Or, do they stick to a song once evolution deems it a success? Perhaps noting some of the music elements of birdsong today will inform an unsuspecting birder of the future how the world’s ecology has changed, adding a layer of music to the already captivating and endless progression of life.

Joanne Garton is a graduating Ecological Planner who is happy to report her listening skills are improving thanks to the birds. Find her wooing confused songbirds with her fiddle in Montpelier, Vermont.

A Blackpoll Warbler’s Daring Trans-Atlantic Flight

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By Bryan Pfeiffer

Two wings and a prayer carry a Blackpoll Warbler on a remarkable journey to South America each autumn. Well, actually, two wings and the audacity to pull off one of the most amazing feats of migration on the planet: a non-stop, trans-Atlantic flight lasting up to three days.

With most of us only speculating for decades about this amazing journey, my colleagues at the Vermont Center for Ecostudies (VCE) today announced proof. Blackpoll Warblers fitted with miniature tracking devices took off from points in either Nova Scotia or the northeastern U.S. and flew south over the Atlantic, with no safe place to land, until reaching Caribbean islands roughly 1,600 miles away.

“This is one of the most ambitious migrations of any bird on earth,” said VCE’s Executive Director, Chris Rimmer, co-author of a research paper published today on the warbler flights. “We’ve also documented one of the longest nonstop, overwater flights ever recorded for a songbird.”

A Blackpoll Warbler and its geolocator. / © Vermont Center for Ecostudies

A Blackpoll Warbler and its geolocator. / © Vermont Center for Ecostudies

This wisp of a bird, weighing half an ounce, with a high, thin pulsing song, breeds in boreal woods from Alaska, across Canada, and into high forests of the Northeast. But migration puts the blackpoll in another league. Tthe vast majority of migratory songbirds that winter in South America take a less risky, continental route south through Mexico and Central America. The blackpoll is a mariner. From its boreal breeding grounds, blackpolls move southeast toward the coasts of maritime Canada, New England, and shoreline points south. Then, when crisp autumn winds blow from behind, the blackpoll – in what is less a leap of faith than an airborne example of evolution – launches out to sea for two or three days of non-stop flapping.

At least that had been the prevailing hypothesis. Until now, we had only circumstantial evidence to support this iconoclastic route: lots of blackpolls at coastal sites in the fall, blackpolls spotted from ships at sea, and relatively few blackpolls in southeastern states and Central America (where we would expect to find them on a more terrestrial southbound route). Although other birds — albatrosses, sandpipers and gulls, for example — are known for trans-oceanic flights, the Blackpoll Warbler, as a forest dweller, is an iconoclast migrating boldly where few of its relatives dare travel.  A water landing would be fatal to a warbler.

To track the flights, VCE and its colleagues in 2013 captured warblers here in Vermont and in Nova Scotia and fitted them with miniature devices called “light-level geolocators,” which resemble songbird backpacks. The warblers migrated south in the fall, spent a winter in the tropics, then returned in spring to North American breeding sites, where VCE biologists recaptured five birds, removed their geolocators, which for the year kepts track of the warblers’ whereabouts. VCE then downloaded the flight itineraries.

Four warblers, including two from Vermont, had departed between Sept 25 and Oct 21 from points somewhere between western Nova Scotia and western Long Island or New Jersey, and flew day and night over the Atlantic Ocean until landing in either Hispaniola or Puerto Rico. Their flight times ranged from 49 to 73 hours.

After reaching the islands of Hispaniola and Puerto Rico, the study’s warblers rested, fed and took off again, this time to cross the Caribbean Sea toward wintering destinations in either northern Colombia or Venezuela.

A fifth bird, which VCE had also first captured in Vermont, likely took a shorter trans-oceanic trip. It departed the mainland on November 4 from Cape Hatteras and then flew nearly 1,000 miles non-stop for 18 hours later to land in Turks and Caicos before continuing on to South America.

On the return trip north, the Blackpoll Warblers took a more westerly route, flying to Cuba or Florida, then moving north along the eastern U.S. seaboard before arriving back on the breeding grounds in Vermont and Nova Scotia in late May.

Unlike GPS devices, which are too large and heavy for the warblers, geolocators use miniaturized sensors to detect and record solar light-level data hundreds of times each day. These data are stored on a tiny computer chip and can be downloaded only if the birds are recaptured. Daily locations can then be inferred from calculations based on day length and the timing of solar noon and midnight.

Why the warblers choose the ocean route isn’t exactly clear. Normally taking weeks or months to complete, migration can be the most perilous part of a songbird’s life. We suspect that Blackpoll Warblers balance the risks of a trans-oceanic flight with the benefits of a speedy and determined migration.

Fat and Flight

coffee-heathThe sea and its trade winds welcome the Arctic Tern and American Golden Plover, celebrated transoceanic migrants. But a warbler? How can a woodland bird make a similar journey?

It does so with the same currency as the tern and the plover: fat. The blackpoll gains weight – a lot of weight – before its flight. After breeding in July, the average Blackpoll Warbler weighs in at about 10 to 12 grams (no more than half an ounce), which means you could mail two blackpolls anywhere in the U.S. for the price of a first-class stamp. But before the fall flight, blackpolls nearly double their mass as they binge on insects, spiders, seeds, and fruit. They store the feast as fat and then burn it efficiently at sea.

Generally, the greater a bird’s fat reserves (as a percentage of its body weight) the farther it can fly without stopping to refuel (eat). After all, risks await birds during those rest stops, including uncertain habitat and predation by hawks, house cats, and other animals.

Yet, the benefits of fat reserves and nonstop flight carry their own risks. A bird focusing on food before migration may be less alert and an easier mark for predators. A fatter bird may lack the acceleration and agility necessary to avoid hawks and falcons in flight. And for a warbler over the ocean, there is no rest stop, no port in a storm, no rescue from a water landing.

On balance, the Blackpoll Warbler, more fat than feather, takes a course evolution has charted at sea. Making the flight from, say, Maine to Brazil, a blackpoll burns less fat than we find in a single serving of Ben & Jerry’s Coffee Heath Bar Crunch.

If only the rest of us had such an effective use for ice cream.

The paper in Biology Letters is: Transoceanic migration by a 12 g songbird. William V. DeLuca, Bradley K. Woodworth, Christopher C. Rimmer, Peter P. Marra, Philip D. Taylor, Kent P. McFarland, Stuart A. Mackenzie, D. Ryan Norris. Biol. Lett.: 2015 11 20141045; DOI: 10.1098/rsbl.2014.1045. Published 1 April 2015.

Beyond the Jeep Road Sits Coyote — Wilderness in 2015

Southwestern desert

Southwestern desert

By Levi Old

On the first day of a 90-day expedition, our team made camp at the end of a jeep road. The afternoon sun, low in the sky, blanketed the desert’s red and orange rocks. Daylight quickly shifted into dusk. The rocks faded into shapes, and dropped shadows on slick rock in the crescent moonlight. The wind-worn surfaces that stood so vibrant in daytime were gone.

After dinner and a meeting about the next day’s plan, we embraced the opportunity to sleep out in the open. I found a flat boulder, climbed into my sleeping bag, and looked up at the night sky. The 10 students wandered around searching for sleeping spots, chatting with nervous anticipation and preparing their new equipment for a night’s rest.

“I bet this never gets old,” said Ben, 20, from Wyoming.

“Seriously,” agreed Lily from New York, “I’ve never seen stars like this before.”

I peeked over the lip of my sleeping bag and noticed the students gazing at the night sky.

The two college students traveled far from their comfortable existences to attend a three-month wilderness leadership course in the heart of the southwestern desert. Along with my colleague, I was their instructor. Around us, there was a more distinguished instructor— wilderness.

The students arrived set to journey through wilderness, the classic romanticized remote landscape, and a wilderness of their mind, body and souls. Students often do not realize that they will travel through a type of land designated by law as Wilderness.

The Wilderness Preservation Act of 1964 designates lands that are separated from roads and motorized use. The act is the federal government’s strictest land preservation law. In 2014 the country celebrated the Act’s 50th Anniversary. The question remains open and often debated by private property activists, business, economists, environmentalists, and others: “Does wilderness still matter?”

Yes. Wilderness is more relevant and timely than ever. Wilderness preserves pockets of ancient ecosystems — from coasts, to endangered grassland prairies, to piedmonts and fragile alpine systems. They remain largely intact. Nearby human communities receive a boost in tourism, and recreational users travel to these wild places for respite. Lyndon B. Johnson said upon signing the bill into law:

“If future generations are to remember us with gratitude rather than contempt, we must leave them something more than the miracles of technology. We must leave them a glimpse of the world as it was in the beginning, not just after we got through with it.”

In 1964, there were 54 Wilderness designations in 13 states totaling 9 million acres. The first Wilderness Area designations included the Gila in New Mexico. The original bill laid the foundation for many other Wilderness bills, some of which were passed into law.

Today there are more than 750 Wilderness Areas from coast to coast. These wild landscapes exist in this country because of the forethought and persistence of conservation leaders.

The Wilderness movement is one of the few times in history in which we as a society designated places set aside for what they are and set at a distance from the human species ability to dominate, take and destroy the very things that help us survive. Wilderness lands are dedicated to preserve havens for clean-water, carbon sequestration, fish and wildlife, and recreation.

Wilderness areas provide the headwaters habitat for clean water sources that reach many of our country’s largest cities: Miami, San Francisco, Las Vegas, Seattle and New York, to name a few. The roadless nature of these areas also makes them valuable fish and wildlife habitat. The law allows regions of our country’s landscape to remain inhabitable by large predators and serve as an example and testament of biodiversity and ecological processes. These wild places include home to grizzly bears, elk, and wolves, and watersheds where native salmon and trout maintain their genetic integrity.

Three-Fingered Jack in the Mt. Jefferson Wilderness Area, Oregon

Three-Fingered Jack in the Mt. Jefferson Wilderness Area, Oregon ©Levi Old

Wilderness draws humans in for many reasons. They arrive to separate from their everyday existences. To vision quest. To challenge comfort zones. To rejuvenate.

The students on these wilderness courses often look to escape the symptoms that follow hours spent in front of a screen, or those times when the hand drives itself to the cell phone on its own. Many seek to separate from the trauma of war or family troubles. For others the symptoms may arise in traffic jams, or walking on concrete so often that the body forgets the intricate features of wild, naked earth.

There are others who are content with the notion that wilderness solely exists:

“We simply need that wild country available to us, even if we never do more than drive to its edge and look in,” said writer and Wilderness advocate, Wallace Stegner. “For it can be a means of reassuring ourselves of our sanity as creatures, a part of the geography of hope.”

Wilderness is a victory in this country’s heritage and an Act and idea that deserves and needs to be defended. Even within the environmental movement itself, the debate continues as to whether these places exclude humans too much. There is a belief among many that we should intermingle in the environment and not feel as though we need to separate ourselves from it and that the concept of Wilderness separates humans further from nature.

Mending Old and New Practices

The leap into the 21st Century passed. The country is in a continuous war for resources. Our earth’s population is over 7 billion and predicted to grow towards as many as 10 billion in 2050 (the elephant in the room). Today’s movement towards ecological peace or “the environmental movement” has deepened the longstanding discussion on the value of setting aside preserved lands. The environmental movement, once driven by large policy and conservation of public lands, now has a new, or at least more diverse presence.

Giant Mountain Wilderness, New York ©Levi Old

Giant Mountain Wilderness, New York ©Levi Old

The neo-environmentalists have treaded bravely into new territories. More young farmers stake claims each year to grow local food, tend soils, and use sustainable agriculture. Urban planners are improving public transportation to offset carbon use and cut down on pollution. River restoration groups remove dams so that salmon can once again swim to their native birth grounds and reestablish themselves as staples of cultural tradition and food sovereignty (a role they held for thousands of years).

Universities and Walmarts employ sustainability coordinators who wash shades of green into their operations. Even permaculture, a regenerative way of living, commonly appears in the national press.

Each of these steps forward is part of a story’s thread — the story of a battle upstream for humanity and earth’s natural systems. They’re not separate, yet woven like an orb weaver’s web — like the web each student will navigate throughout life.

The modern environmental movement’s new approaches should make any longtime fighter in this work proud. However, it should not allow us to sit still or dismiss victories of the past and their value in the present. At the closing of the Act’s 50th year, we celebrated the role of Wilderness in our country’s past and future. In 2015 and beyond, however, our work must continue. The managed landscape cannot be mistaken for unmanaged country.

Looking at the Mission Mountain Wilderness Area, Montana

Looking at the Mission Mountain Wilderness Area, Montana    © Levi Old

One loss in the walls of Washington, and this Act could be stripped of its foundations, making wild lands exposed to numerous threats. Direct attacks on the law take place each year in our nation’s capitol.

One bill (H.R. 4089), for example, pushed by the extractive industries and disguised as pro-hunting legislation would have allowed motorized use and other development in protected Wilderness areas. It passed the U. S. House, but died in the Senate. These bills have the ability to destroy the hard work and value of these unmanaged landscapes.

We should not be fooled that Wilderness areas are completely devoid of human impact. Not only are humans visitors to Wilderness areas, the interconnectedness of ecological systems makes non-native species, climate change and air pollution among the many threats to these lands. These landscapes are delicately chosen because they are like no other areas — for their values to humans and ecological processes.

Named after the famous conservationist, the Marjorie Stoneman Douglas Wilderness Area in the Everglades National Park represents the woman who fought hard to protect this ecosystem of cypress marshes and mangrove forests. She secured a future for Miami’s water source and a haven for biodiversity. She stated at the beginning of her book, The River of Grass:

“There are no other Everglades in the world.”

Everglades National Park, home of the Marjorie Stoneman Douglas Wilderness Area

Everglades National Park — home of the Marjorie Stoneman Douglas Wilderness Area

Will we let these special places be exploited for short-term benefit, or will we fight to maintain and protect more? The younger generation and new breed of environmentalists can step up and lead the charge, mending new conservation techniques with foundations like the Wilderness Act.

Fracking and Fire

On the expedition’s final night we sat around telling stories, and Ben reflected on the gratitude he felt for the places set aside from our own species ability to fragment and destroy. He said he appreciated the lack of roads or drill rigs in the Wilderness areas we traveled throughout the course. He told a story about his home in eastern Wyoming, where drills checkered the landscape and trucks carried water to natural gas fracking operations.

The boom really changed the sagebrush steppe landscape where he grew up. He spoke about how the land’s value to human needs will outlast the natural gas extraction, and he hoped it would not ruin his hunting and fishing grounds, or his family’s water source.

Out here we know that there are wild landscapes protected by the Wilderness Act, which we learned about on course, he explained. “What forethought went into the protection of these places,” Ben said. “Those advocates were wise and planning for future generations. I would like to be one of those people.”

That night we sat in a cliff-side cave overlooking an arroyo. After weeks of challenging herself with primitive fire techniques, Lily started the fire we sat around. She also canoed, backpacked, wrestled with group leadership, communication, cooking, and a fear of heights — all under the guidance of Wilderness.

Each night Ben, Lily and our expedition crew stargazed far from city lights. As an educator, Wilderness provides me the finest of classrooms, a wild place that doubles as a wise mentor. That evening, I sensed we all knew that Wilderness can be harsh, often unforgiving, yet rewarding beyond the best author’s and the best speaker’s words.

As we went to bed, coyotes yipped into a light covering of cirrus clouds.

Rare pocket of thousand year-old, old growth Pacific Yew trees. Indian Creek, Frank - Church River of No Return Wilderness

Rare pocket of thousand year-old, old growth Pacific Yew trees. Indian Creek, Frank – Church River of No Return Wilderness ©Levi Old

Douglas, M.S. (1947). The Everglades: River of Grass. New York, NY: Rinehart & Company.

Govtrack.us. (n.d.). H.R. 4089 (112th): Sportsman’s Heritage Act of 2012. Retrieved from https://www.govtrack.us/congress/bills/112/hr4089

The Wilderness Society. (n.d.). General Format. Retrieved from http://wilderness.org/article/wilderness-act

 

Shadows and Sex

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Red Squirrel / © Bryan Pfeiffe

By Bryan Pfeiffer

YOU DON’T NEED PUNXSUTAWNEY PHIL to know which way the wind blows. Groundhog Day ain’t about shadows. It’s about sex. Birds and rodents are beginning a season of foreplay.

No, spring is not around the corner – at least not here in Vermont. Songbirds don’t rely on the vagaries of weather to calculate their breeding cycles. Instead, they schedule mating and nesting to take advantage of a reliable abundance of food for their offspring, mostly insects, which happens in May and June here at our latitude. As the days grow longer, birds do get ready to, well, um, make more birds. It’s why we’re starting to hear Black-capped Chickadees, Northern Cardinals, House Finches and other birds errupting into song on sunny mornings.

Black-capped Chickadee / © Bryan Pfeiffer

Black-capped Chickadee / © Bryan Pfeiffer

Day length is a far more reliable calendar than weather. It is not entirely clear how birds measure day length, but we do know that photo-receptors in bird brains sense increasing light. It triggers the production of hormones that act like birdie Viagra. Their sexual organs revive from a state of dormancy. So when the food is there in May, songbirds will be ready … you know, physically.

February 2 is indeed significant. It falls about halfway between the Winter Solstice and the Spring Equinox, a period celebrated in various ways in human traditions from Paganism to Christianity. And early February is when we start to get 10 hours of daylight – February 5 this year. It seems to be a turning point for wildlife.

But why the groundhog? Couldn’t we have picked a loftier critter to represent the coming of the light? As it turns out, this rodent is indeed a worthy messenger of spring. In February, woodchucks begin to emerge from hibernation on the prowl. They need to breed soon so that females produce litters during greater food abundance in April and May. Males emerge from their burrows to find and visit with females. But many of these early encounters are merely courtship visits, which pay dividends, research suggests, when it comes time to breed a bit later. It’s sort of like another February ritual – Valentine’s Day.

Squirrels aren’t so tactful. Female red squirrels are in estrus, receptive to males for breeding, for about eight hours on only a single day during this season. And male squirrels outnumber females in the wild by as much as five to one. The consequence of this skewed gender ratio and hard-to-get females is that life during the breeding season can be, to say the least, challenging for the male. He’ll spend lots of time following her in the days before she is in estrus. Should the male be too forthcoming, too eager before she is ready, she will rebuff his advances with a swat to the face or a painful bite. (I hate it when that happens.)

And when those precious eight hours finally arrive, a male is hardly alone in this drama. He often must compete with or fight other males for her affections – actually for a copulation that might last only about 20 seconds. Out there in the trees, it’s a free-for-all. “To the casual observer, what ensues is probably best described as pure and unadulterated chaos,” write biologists Michael A. Steele and John L. Koprowski in their fantastic book, North American Tree Squirrels.

So let’s recognize the real significance of Groundhog Day. This isn’t a holiday about six more weeks of winter. It’s a celebration of romance, even if it turns out to be unadulterated, chaotic rodent romance.

To Brave the Cold

The sun had been up for an hour and the day was already warming. As I sat down to a steaming bowl of cinnamon oatmeal, Bernd walked into the cabin and announced that it was -24 degrees Fahrenheit outside. This made the rest of the week seem balmy, with temperatures fluctuating between -5 and 28 degrees F. Soon we would head outside for an exploratory ramble. It was just another day in Bernd Heinrich’s Winter Ecology class.

When I tell people about winter camping their reaction is often one of shock; sometimes I provoke a chorus of “That sounds terrible!” People ask these experiences with comic incredulity, but their questions give me the chance to explain why braving the cold is worth it.

  1. Winter is beautiful.

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    Photo by Bonnie Richord

The landscape sparkles with snow, the late-afternoon sun paints the hills pink, and the tree silhouettes stand twisted against the sky. After a snowfall, the world is transformed, quiet, and peaceful.

  1. Wildlife!

While many animals are sleeping or have left town, the ones that remain can be easier to see against the backdrop of snow and bare tree branches. Below, check out an owl sighting from winter ecology.

  1. You get to eat so much.

When we spend time in the cold, our metabolism cranks up. We eat more so we can produce more heat. On winter camping trips, when I’m outside 24/7, I eat twice what I normally do. Imagine eating as much butter as you want and snacking 3-12 times a day. Delicious.

  1. You can get used to the cold.

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    Photo by Bonnie Richord

While your toes might be chilled and you will always appreciate warm tea, with the right layers and by staying active, many people can be comfortable in the cold. Put on some long johns and snow-pants and you might even find yourself sweating as you walk.

  1. You earn hard-core points.

Once you’ve been outside in the negative 20’s, ten degrees feels pleasant. Any time you’re facing a challenge in another aspect of your life, you’ll be able to remember how strong and adaptable you were in the winter.

 

So, air yourself out this winter. Pack a hot thermos, some exciting snacks, and who knows, maybe you’ll see a winter wonder- a snowy owl, a golden-crowned kinglet, or some extremely fluffy chickadees.

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Photo by Shelby Perry

 

 

 

Kiss This: Mistletoe’s Higher Calling

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Great Purple Hairstreak (Atlides haleus) / © Bryan Pfeiffer

GET YOURSELF UNDER SOME WILD MISTLETOE this Christmas. Your gift might be a shock-and-awe butterfly called Great Purple Hairstreak.

Mistletoe is a plant that grows on trees or shrubs. And it’s a bit of a leech, a hemiparasite, which means mistletoe draws minerals and fluids from its host. But mistletoe is also photosynthetic, generating some of its own energy demands from sunshine. Oh, by the way, there is no one mistletoe. The world has more than 1,000 mistletoe species. I’ve got one of them in a cottonwood next to my cabin here in New Mexico. Mistletoes grow flowers, have pollinators, and produce fruits like many other plants.

In Arizona this past weekend, among thousands of butterflies, I encountered a single Great Purple Hairstreak. That’s usually how we find them, sluggish and alone, about the size of your thumbnail, crawling among flowers and lapping up nectar. But the business side of this butterfly, at least when it comes to mistletoe, is the caterpillar. Great Purple Hairstreak caterpillars eat mistletoe species in the genus Phoradendron (and maybe others).

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Range map for Great Purple Hairstreak

After all, for butterflies, it’s all about the host plant – the plant on which (or near) the adults lay eggs and on which the caterpillars feed. So if you’re looking for a particular butterfly species, start by looking around its host. Great Purple Hairstreaks range across central and southern latitudes of the US, where we find a lot of that mistletoe. That’s the butterfly’s range map to the right. (Sorry, northerners.)

But this isn’t to say that we don’t have mistletoe up north. I’ve seen dwarf mistletoe (which I think is Arceuthobium pusillum) at home (where it’s rare) on black spruce in a bog in central Vermont. Dwarf mistletoe is an odd beast whose young shoots look, um, er, well … you’ll see below.

So, here you are, a few more photos: First, another Great Purple Hairstreak, which I photographed in Delaware; on this one you can see just a bit of its shocking orange abdomen. Then the mistletoe outside my cabin (where I’m wrapping up a book of essays, by the way). And finally that obscene dwarf mistletoe from Vermont.

Oh, by the way, Olivia Judson scooped me with a wonderful essay on mistletoe in Tuesday’s New York Times, although she didn’t mention Great Purple Hairstreaks.

Happy Holidays, everyone.

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Great Purple Hairstreak in Lewes, Delaware / © Bryan Pfeiffer

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The mistletoe out back.

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The dwarf mistletoe back home in Vermont.

Partial Migrants: Should I Stay or Should I Go?

By Sonia DeYoung

Outside my window, a robin pecks around in the rain. It’s the day before Thanksgiving, and the forecast calls for the rain to turn to snow tonight in my Massachusetts hometown. So why isn’t this robin right now flying south toward a warm, easy winter?

American robins are facultative partial migrants:  they decide each year whether to migrate

American robins are facultative partial migrants: they decide each year whether to migrate

Casual birdwatchers see robins as harbingers of spring, but you can actually find them year-round throughout much of the U.S. Based on my own observations, robins seem to stick around more now than they did twenty years ago—perhaps global warming plays a role in that trend (see November 6 post). But climate change can’t explain why some robins flee wintertime and others take their chances.

[Update: The day after publishing this post, I stumbled across an article by biologist Mark Davis saying that more robins stay in the north for the winter now because of a greater winter food supply: they happily eat the berries of several increasingly common non-native species.]

Many birds, like warblers and hummingbirds, migrate annually no matter what. Others, including robins, kingfishers, and chickadees, are “partial migrants”: within a single population in a given year, some will migrate and some will not. Backyard birdwatchers who rejoice in the first robin of spring aren’t necessarily unobservant. There are fewer robins around in winter, and those that do stay often roost in bogs and swamps instead of backyards. Each year, a robin must decide based on the available food supply whether to migrate; a snowy winter landscape can never provide as much food as the same land in summer. Some robins may even leave mid-season if the conditions turns especially harsh.

They’re taking a gamble either way. Birds who reside year-round in temperate climates risk a 50-80% chance of death each winter. Migrants do a little better, with at most a 50% chance of death. But they invest a great deal of time and energy in migration that they could have put toward reproduction. Temperate residents make up for their high winter death toll with their better success raising offspring.

European robins are obligate partial migrants: genes determine which members of a population will migrate

European robins are obligate partial migrants: genes determine which members of a population will migrate

Not all partial migrants have to make this annual choice. Within a single population of European robins (not closely related to American robins), genes dictate which individuals will migrate and which will stay. With these birds, migrants are born, not made. Gene-determined migrants like European robins are called obligate partial migrants, while American robins are examples of facultative partial migrants.

Still other kinds of migrants do make a choice, but it’s a group decision. Evening grosbeaks and snowy owls, for instance, will leave their typical wintering grounds en masse if the autumn produced a poor seed crop. Then they pop up in unexpected places in what’s called an irruption: an unpredictable winter boom of birds.

The robin outside my window, though, didn’t have the advantage of consensus to decide where to spend this winter. She reminds me that animals are individuals who must make daily life decisions based on their experiences. Watching her hunched under the cover of a dripping rhododendron, I hope she made the right one.

Information gathered from The Handbook to Bird Biology published by the Cornell Lab of Ornithology; Living on the Wind: Across the Hemisphere with Migratory Birds by Scott Weidensaul; and the Audubon Society and Smithsonian field guides to North American birds.

 

Give it a Shot: Staying Safe in the Woods During Rifle Season

Shelby and one of her dad's bucks sometime in the early 90's.

Shelby and one of her dad’s bucks sometime in the early 90’s.

It’s hunting season, and this year I’m working through my end-of-semester stress with a rifle.  I’ve never been a hunter before, but, as a native Vermonter, deer camp, hunter-safety orange, and the first rule of gun safety (always point your muzzle in a safe direction!) have been in my vocabulary since childhood.  As I prepare for my first rifle season as a hunter, I have been surprised to find that many of my classmates did not grow up around hunting, and haven’t really thought about what it might mean to them.  Staying safe during hunting season really boils down to three main points, and shouldn’t be intimidating or frightening.

  1. Be visible.  Wearing hunter-safety orange any and every time you go out in the woods during rifle season is a must.  A lot of people think wearing any bright color will do, but almost nothing is more visible and recognizable as human in the late fall forest than hunter-safety orange.
  2. Be respectful.  Few things are more frustrating for a hunter who has been shivering silently in a tree stand since dawn than a person or dog thrashing obliviously past.  If you think there might be a hunter already in the woods it’s best to stick to heavily traveled trails or to just avoid the area during rifle season altogether.  Less about safety and more about etiquette, respecting other legal uses of the forests you love is a condition on which your own access depends.
  3. Take it seriously.  “It won’t happen to me” is the wrong approach to safety during hunting season.  Spend 8 hours looking for deer in the woods and your brain will start to make them out of everything – tree branches are antlers, the crunching leaves under a retreating rabbit are footsteps.  I am not condoning the actions of anyone who would pull the trigger before being absolutely certain of their target, but I am saying that it is wise to set yourself up for success.    Never assume your safety is someone else’s responsibility.

I love hunting season; it is full of memories of excitement and anticipation for me.  When my dad got a deer it was a big deal, and I couldn’t help but get caught up in the excitement, even during my 10 years as a recalcitrant teenage vegetarian.  The deer would hang from the rafters of our garage for a time, while it was disassembled into small freezer paper packets labeled in my father’s shaky hand with strips of masking tape.  I was in rapture of these deer, their beautiful fur and antlers an endless source of fascination for my young mind.  The resulting packets were a staple of my childhood winters, when at the hands of my mother they would blossom into venison stews and chili that bubbled alluringly all day in the crockpot.

My dad hasn’t gotten a deer in quite a while now.  He hunts less than he used to, and many of his cousins and hunting buddies have moved out of state.  I’m not quite ready to let go yet though, so I’m putting down my books and picking up a rifle this year, and I’m going hunting with my dad.  No one is more excited than he.

Shelby is a first year graduate student in the Field Naturalist program.  She is very much an animal lover, but reserves the right to occasionally kill and eat them.  She is also a very good shot.  

It’s Getting Hot in Here

By Maddy Morgan

Most of us have probably seen the headlines: “2014 on Track to be Hottest Year on Record,” or “Climate deniers lost for words: 2014 set for hottest year on record.” Yikes! Is it true? If so, what does this mean for us?

The story behind the headlines is based partially on information on the month of August. NASA and NOAA have both confirmed data showing that this August was the warmest August on record. Although New England’s August was relatively mild, temperatures in Central Europe, northern Africa, parts of South America, and western North America exceeded the norm. Ocean temperatures were also warmer than usual.

All this added up to a record-setting August. One month may be no big deal, until you consider that this makes August the 354th consecutive month that is above the 20th century average. And the top 10 hottest complete years on record are 1998, 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010, and 2013. I’m beginning to see a trend.


If, like me, you hate hot weather and despair at the thought of these rising temperatures, take heart in the map above, which shows most of the United States falling below 20th century averages. If we get too hot we can always relocate to the midwest.