February
February spells “winter,” just like January. The weather experts tell us that, in February, the average temperature is a little higher and snowfall is a little lower than in January, but the fluctuations around these mean values are so unpredictable that the average human detects no change. Much of the natural world also treats February as an extension of January. Lie low to survive the cold. But some creatures that are active through the winter are alert to increasing day length, the most reliable cue that spring is on its way. At our latitude, the time from sunrise to sunset is extended by a full hour, from ten hours to eleven hours, during the month. Every year, I am astonished that the dawn chorus of birds, hushed through the darkest days of winter, starts up in the wintry wastes of February.
With the February dawn chorus in mind, “The Sound of the Syrinx” celebrates the opening performer, the male cardinal, and the hardware that enables him and other birds to sing. This essay is preceded by an exploration of the remarkable strategies adopted by turtles and newts to survive the winter (“Living with Ice”) and is followed by an examination of the bald eagles that overwinter on the lakeshore (“The Great Seal”). I conclude this chapter with some heartfelt praise of flowers (“Lilies in February”), which are sorely missed by late February.
Living with Ice
When the wind and snow barrel in from the high Arctic, our world becomes white and gray. The clouds occasionally part to reveal a sky of the lightest blue and a pale sun that makes the snow glisten. The ground is rock hard, the waterfalls are frosted into icicles, and the creeks and lakes are covered in a layer of ice that is the color of steel.
Ice. For us city types, ice is a peril of winter. When the air is well below freezing, a sheet of ice may be hiding under a cover of snow on the sidewalk. When the temperature hovers around the freezing point, both rain and recently thawed snow are transformed into an invisible but slippery glaze on the streets, sidewalks, and driveways. The only solution is salt, and lots of it, even though the underbelly of every car becomes rusted as a consequence. We are told to walk like a penguin to protect against bruised bottoms and broken limbs.
However, living with ice is not only about the rapid depreciation of the value of our cars and poor imitations of penguins. For many, living with ice means being trapped for weeks on end under a thick, icy layer. I have plenty of opportunities to think of the captives: when I stand on the bridge overlooking the pond at the Cornell Botanic Gardens, when I check the view of Cayuga Inlet (a creek that opens into Cayuga Lake) through the plate glass window of the indoor swimming pool, and when I walk the city park trail that runs alongside the frozen southern end of Cayuga Lake.
The ice captives include snapping turtles, which spend the summer swimming languidly through the murky waters of local ponds, and painted turtles, which bask in the summer sunshine on partially submerged logs. As the water cools in the fall, the turtles swim down to the muddy bottom, dig a hole, and bury themselves. The temperature down there drops to 39°F (4°C) for the entire winter. That’s chilly, but it is a far better way to sit out the winter than on land, grappling with the hazard of getting so cold that ice crystals form in the blood or tissues, which would be curtains for a turtle.
What’s more, a turtle doesn’t have to worry about its energy bills because it turns its metabolism down to about 1 percent of the summer rate. This means it can manage without food for three to four months. Its oxygen needs are also trivial and can be met without breathing. It just hangs its head, legs and tail out in the sloppy mud, and lets the oxygen diffuse across its skin into its bloodstream. As the winter progresses, the oxygen supply in the mud gradually declines. No worries—both snapping turtles and painted turtles can switch to anaerobic respiration, without oxygen. You might imagine that this would lead to a buildup of lactic acid (like in your legs when anaerobic metabolism kicks in after running up several flights of stairs), which would acidify the blood and cause physiological mayhem. Our turtles deal with that complication by dissolving out some of the calcium from their shells, and the resulting calcium carbonate in the blood neutralizes the lactic acid. There is one last difficulty. It could get a bit boring, even claustrophobic, down there in the slime, but that is really no bother because the turtle’s brain is operating in minimal maintenance mode, just like the rest of its body.
Another regular in our ponds are newts, specifically the eastern newt, also known as the red-spotted newt because of bright red spots encircled in black along the side of its otherwise dull green body. Unlike the turtles, newts remain active in the water column under the ice throughout the winter, although they are in the slow lane because of the cold. There’s not a lot of food, but that doesn’t appear to be an issue because newts can fall back on fat reserves laid down in the late summer and fall. No, the biggest concern for an overwintering newt is the oxygen supply under the ice because, unlike turtles, newts cannot switch to oxygen-independent anaerobic respiration. When a pond is covered in ice, the water is sealed off from the oxygen-rich air, and the only way to replenish oxygen is through photosynthesis by the aquatic algae and plants—but if the ice gets covered in snow, it can get very dark in the pond. When that happens, the oxygen gets depleted, resulting in what are known as newt winter kills.
It is certainly tough to be a newt. An added complication for the eastern newt is its unusual way of life. It starts off like other newts: as an egg attached to water plants in the spring, then as a tadpole with frilly gills and legs through the summer. The special quirk of the eastern newt is that, as the days shorten, the youngsters—known as efts—develop wanderlust. They crawl out of the water, resorb their gills, and, quite literally, wander the world for two or three years. These efts are bright red. We often see them crawling about in the forest during the summer. During the winter, they hibernate on land, sitting out the cold under logs and in leaf litter.
All this adds up to a realization that every adult newt we see in the early spring is a master of survival. It has survived at least two winters at risk of turning to ice in leaf litter plus at least one winter sealed under ice in danger of suffocation.
Our local turtles and newts put our human anxieties about ice into perspective.
The Sound of the Syrinx
During the second week of the month, the male cardinal in our backyard told the world that, for him, this was the first day of spring. It was dark and several degrees below freezing with a brisk northwesterly wind. About fifteen minutes before daybreak, he started calling and singing: pip, pip, pip, chewee-chewee, then a whistle ending in a fancy little trill. He kept it up until about ten minutes after dawn and then took a break, presumably for his breakfast. He has been back on singing duty every morning just before sunrise since then. Although both the male and female cardinals have been calling all winter, the predawn routine of the male is new. He must have decided that it was time to tell everyone and everything that this territory is accounted for and he survived the night. He did not fall prey to the local cat, the great horned owl, or the atrocious weather. Any other cardinals lurking around have received their daily marching orders: go and lurk somewhere else.
Most days, the cardinal has been our sole songster. Then the wind shifted briefly to the south and southwest earlier this week, bringing us a snatch of Florida weather. It wasn’t record breaking, but it reached 60°F (15°C) with brilliant sunshine. Other birds also decided it was spring. The chickadees were calling, chickadee-dee-dee and pheebee-pheebee, along with the tufted titmice, peeterpeeter-peeeterter. Best of all, a mourning dove was perched high in the black walnut tree, his slim body, small head, and narrow tail silhouetted against the sky. I know it was a male because he was cooing, gently advertising his availability to any females in the neighborhood. As the sunshine warmed the air, the cooing became more insistent. Before long, there were male doves perched in conspicuous places up and down the street, all making the most of the springlike conditions. By this time, the doves didn’t sound quite so gentle. Mourning doves are professionals in the art of competitive cooing.
And then there was another call: a gargling, then a swallowing sound, and a little whistle. I was mystified. I clutched at my phone for the Merlin Bird ID app to solve the problem. It was an eastern cowbird. Just as our songbirds and doves are getting into courtship mode, anticipating a happy family of nestlings, so the local cow-birds are setting up for another season of sneaking eggs into the nests of unsuspecting victims.
Of course, our experience of spring in February was brief. The temperatures have since plummeted, accompanied by snow showers, and we are back to the wintry wastes. The chickadees and tufted titmice twitter in subdued tones, the mourning doves are silent, and the cowbirds are gone. Nevertheless, our brave cardinal wakes us up daily as he sings in the darkness from the maple tree just outside our bedroom window.
From a musical perspective, our early season songsters are not so special. They are not nearly as loud as the Carolina wren, who will assuredly be singing before long, and their repertoire is not as melodious or complex as the catbirds and orioles that will be returning to us in early May. Overall, the total repertoire of calls and songs of most birds is surprisingly complex and loud, compared to mammals of similar size.
This is where the syrinx of my title comes in. Birds have abandoned the standard voice box of other land-living vertebrates: the mammals, reptiles, and amphibians. That is the larynx, which sits at the top of the windpipe and sports two little bundles of tissue called the vocal cords. For unknown reasons, the ancestors of the birds decided to delve deeper, all the way to the far end of the windpipe, where it divides into two pipes (bronchi) that take air into each of the two lungs. Birds don’t depend on the vibrations of vocal cords to make a noise. Instead, they let the walls of the syrinx vibrate. Just as the pitch of the human voice is determined by muscles that shorten or lengthen the vocal cords, so the pitch of birdsong is dictated by muscles that alter the tension in the syrinx wall.
The important point about the syrinx is that it allows for bigger, better songs, but only because of a second anatomical innovation that birds are heavily (or should I say lightly?) into air sacs. A complex set of muscles alternately compresses and inflates the different air sacs, making them act like bellows, pushing and pulling air across the lungs. That is good for oxygen supply and the expensive business of flying, and it also creates a nice, steady airflow through the syrinx for making noises. What’s more, these air sacs are great resonance chambers. The sound from the syrinx can be bounced off the walls of the air sacs, increasing the intensity of the sound, just like the sound board of a piano or the body of a violin.
There is more to a bird than its voice box. A bird must also breathe. Birds usually sing only when they are breathing out. Birds can sustain long songs, for example the extended trill of the cardinal, without keeling over from a lack of oxygen because they take mini breaths, up to twenty of them every second, that interrupt the sound for such short durations that it is not detectable. Of course, coordinating the muscles for breathing and singing is a very complicated business, especially since singing involves precise changes in the activity of multiple muscles that control the tension in the syrinx wall.
Let’s add another layer of complexity. As I have already said, the syrinx of most birds is at the junction of the windpipe and bronchi. This means that singing can involve parallel vibrations in the two bronchi. So why not make noises of different pitch in the two bronchi? No reason why not! Many birds do, making tunes with ascending and descending lines at the same time. The thrushes are incredibly good at doing this. You could say that a thrush is singing a duet with itself. But the syrinx is restricted to the bottom of the windpipe (it doesn’t extend into the bronchi) in a few birds, including ovenbirds and brown creepers. Next time you see a brown creeper, remind yourself of something we have in common with them: we also can only vocalize just one pitch at a time.
The constraints imposed by having a syrinx in your windpipe are nothing compared to losing your voice box altogether. The turkey vultures that have recently returned from downstate and are soaring above our backyard are in this category. They are silent, apart from the occasional hiss and whine. Turkey vultures get along just fine without indulging in any cheeps, chirps, chatters, or croaks. The story of the syrinx reminds us that there’s no single way to run a life, at least in the bird world.
The Great Seal
It has been an excellent winter for sightings of bald eagles. Several individuals have been hanging around at the southern end of Cayuga Lake for weeks. The birds that we have seen are immature, mostly brown with some dashes of white on the body. It takes four to five years for a bald eagle to acquire the adult plumage of a uniformly brown body with a brilliant white head and tail, plus a yellow beak and legs. Our overwintering birds could be born-and-bred locals or migrants from farther north.
It feels very special to be living alongside eagles. Somehow, the word eagle conjures up images of magnificence and power. The eagle symbolized Zeus, the chief god of ancient Greece, and it was the standard for every army legion of ancient Rome. Then it was adopted to represent St. John, one of the four Christian evangelists, and in the last five-to-six hundred years, the eagle has been used widely in heraldry, especially by monarchs in continental Europe. These symbolic eagles are all derived from the golden eagle, Aquila chrysaetos.
When the United States decided it needed a national symbol, it is hardly surprising that an eagle was chosen. What’s more, one would expect the choice to be the golden eagle, which is distributed across both North America and Europe.
Despite this expectation, we all know that the eagle selected to represent the nation was not the golden eagle but the bald eagle. The story of how and why is rather convoluted.
We have to go back to July 4, 1776, and an assembly room in the Pennsylvania State House in Philadelphia where the Declaration of Independence was duly signed. What next? What is the first thing you would do after declaring unilateral independence from a superpower headed by a tyrant given to episodes of madness? I would call up any able-bodied person and get them armed in anticipation of an uninvited visitation by the trained army of the aforesaid tyrant. That was certainly on the to-do list, but our heroes thought bigger. Within hours of signing the Declaration of Independence, they set up a committee. Three key people were to spend their time designing a coat of arms, which would be the logo for the new country and the imprint for the wax seal appended to every important document. It would be the Great Seal.
The three talented men sent off to design the seal were none other than Benjamin Franklin, Thomas Jefferson, and John Adams. Unfortunately, none of them had attended the mandatory training course on teamwork run by the local personnel department. They came up with three different ideas. Franklin went with the Egyptian king drowning with his chariot and horses in the Red Sea while Moses and the Israelites looked on from a high cliff; Jefferson and Adams preferred Hercules, although they differed on the details.
Unsurprisingly, Congress was unimpressed by the committee’s offerings and set up a second committee. When that was not good enough, they set up a third committee . . . then a fourth. Exhausted by all of this, the fourth design, created by Charles Thomson and William Barton, was accepted, and the seal was in place in 1782. It took six years to design a logo. The central feature of the seal was a mostly brown bird that was suspended, as if on an invisible piece of string, with belly forward and wings outstretched. Its two legs were splayed out like arms, one clutching what looks like a bunch of flowers (but was actually an olive branch) with thirteen leaves and thirteen fruits, and the other holding a bunch of thirteen arrows. The bird’s large beak grasped a yellow ribbon bearing the words E Pluribus Unum (“Out of Many, One”). Above this is a decorated circle with thirteen yellow stars. The nascent country was big on thirteen because, at that time, it was made up of thirteen states.
The bird on the Great Seal was an eagle—not a golden eagle but a bald eagle. The only clues to its identity were its white head and white tail. I suspect the designers had worked from a poorly prepared stuffed specimen.
Benjamin Franklin was incensed. He raged that the eagle looked like a turkey. In due course and after Franklin died in 1790, the US government responded to Franklin’s complaints. The design of the seal was modified in 1825, then again in 1841 and 1877, but none of these quite cut the mustard. In 1885, yet another committee hit the sweet spot with a rather grand and formal bald eagle. The 1885 Great Seal remains unchanged to this day, adorning every $1 bill.
But we’re getting ahead of ourselves. All that is still in the future. Let’s get back to Benjamin Franklin, who was never shy about voicing his opinions. The poor artistry of the 1782 Great Seal was not his only problem. Franklin was dismayed that his country was adopting the bald eagle as its symbol of freedom and democracy. His disquiet is best expressed in his own words, as written to his daughter (Franklin 1784): “For my own part I wish the Bald Eagle had not been chosen the Representative of our Country. He is a bird of bad moral character. He does not get his living honestly. You may have seen him perched on some dead tree near the river, where, too lazy to fish for himself, he watches the labour of the fishing hawk; and when that diligent bird has at length taken a fish, and is bearing it to his nest for the support of his mate and young ones, the bald eagle pursues him and takes it from him. With all this injustice, he is never in good case, but like those among men who live by sharping and robbing he is generally poor and often very lousy.”
Benjamin Franklin was an observant ornithologist. The bald eagle is principally a scavenger. Fish are the main item on its menu, and it favors dead fish over live fish. It is also very content to pirate food caught by other birds, including herons and osprey (that’s Franklin’s fishing hawk). Only when it is seriously hungry will a bald eagle deign to hunt for itself.
Unlike Benjamin Franklin, I don’t see the bald eagle as a creature of bad moral character. Instead, I see a bird that has recovered from a close shave with extinction. Originally widespread in every state of the union, the bald eagle’s habitat was reduced to a few remote locations around the Great Lakes and west of the Rocky Mountains by the 1970s. Its comeback over the last fifty years has been nothing short of astounding. In 2007, the bald eagle was removed from protection by the Endangered Species Act, and its population now exceeds 300,000 individuals.
Benjamin Franklin couldn’t have known, but the bald eagle on the Great Seal has come to signify the astonishing capacity of nature to recover, if we only give it a chance.
Lilies in February
Now that the end of February is approaching, we are starting to tell ourselves that we are over the worst of the winter. The days are getting longer; the average temperatures are increasing, although still almost entirely below freezing; and . . . the self-talk fades away as we stare numbly at the winter scenery, the white of snow, and the black and gray of gaunt leafless trees silhouetted against the persistently dark gray skies in this flowerless land. That’s the problem: it’s flowerless! Lilies in February are as likely as a flying saucer landing in our backyard.
Experiments conducted by psychologists have demonstrated how flowerless is bad for us. Flowers make us happy; we smile and are more content in the presence of flowers. Flowers are even claimed to improve our memory and capacity to reason. What can we do in flowerless February? One solution is to use our imagination. We can think about flowers to keep up our spirits on the most miserable February day. In that spirit, here is a story about flowers.
Let’s start at the beginning. That’s about 170 million years ago at the height of the Age of Dinosaurs (also known as the Mesozoic Era), when something strange was happening in the green and pleasant land. The reason for all the buzz was a new kind of plant whose reproductive parts were decorated with modified leaves. It was the time of the first experiments with petals—and the first flowers. The fossil record tells us that flowers started off big, a bit like a water lily or a magnolia. The petals of the first flowers are usually portrayed as brilliant white, but I am unaware of any evidence that this is more than an educated guess.
The origin of flowers had an enormous effect on some of the insects that had previously made a living by eating the reproductive tissues, especially the abundant male spores, of flowerless plants. Many of these flowerless plants didn’t just tolerate these insects; they invited the tiny diners in and used them as a delivery service. Some of the many spores on which the insects were feeding would stick to the insects’ bodies and, when they visited another flower, the spores would fall off onto the female reproductive organ. In other words, the relationship between plants and insect pollinators is much more ancient than flowering plants.
Nevertheless, flowers changed the pollination game. Exploiting insects’ keen vision, the first flowering plants used the bright color of their petals to advertise the precise location of their protein-rich pollen granules, which contain the male gametes. Before long, many flowering plants added in delicious scents and, best of all, sugary nectar to attract the insects. Keep each nectar snack small, and the insects work all day to get tiny mouthfuls of sugar from one flower after another, inadvertently transporting pollen among the flowers. Various plants changed the paradigm to attract birds (bright red flowers that are readily visible to birds but beyond the visual range of most insects) or bats (large, pale flowers that bloom at night). As a result, our world is filled with an amazing diversity of flowers and an equally amazing diversity of insects and other animals that earn their daily bread by consorting with flowers.
Then humans happened. As I’ve already written, humans love flowers. Ethnobotanists and archaeologists have shown that the pleasure of flowers is a constant across many cultures and over the millennia, indicating that flower appreciation is hardwired into our brains. The influence of flowers on our emotional state explains some of the ways we interact with flowers. Humans invest inordinate resources into constructing and maintaining ornamental gardens. Some gardens are famous, such as the legendary Hanging Gardens of Babylon built by the Assyrian King Nebuchadnezzar II for his wife (2600 BCE), the formal gardens of Versailles constructed for King Louis XIV of France (1661), and Frederick Law Olmsted’s naturalistic landscapes of New York City’s Central Park (1858), but most flower gardens are small-scale, amateur, and constructed in backyards. Humans also value floristry, the art of creating beautiful arrangements of cut flowers. Posies, bouquets, and floral arrangements in vases have been popular from the days of ancient Egypt (2500 BCE) to today. In some cultures, cut flowers are strung together to create elegant designs, as in the Hawaiian lei of plumeria or orchid flowers and the garlands of roses, violets, and lilies that decorated the walls of houses in ancient Rome.
Humans do not only use flowers to promote their individual sense of well-being. They also use flowers to communicate with other people. Flowers convey joy at a wedding, romantic love on Valentine’s Day, sympathy at a funeral, apologies for something badly done, and so on. A gift of flowers can say, “My heart goes out to you in your troubles,” “I love you,” or “I am so sorry; please forgive me.” Say it with flowers.
The outsized influence of flowers on our lives comes, in large part, from our influence on flowers. By selective breeding, we have created flowers that are larger, more colorful, more complex, and more scented, and so pack a bigger punch on our emotions. For millennia, we have been busy transforming flowers that were designed to manipulate pollinators into flowers that are emotionally pleasing to humans. For example, today’s myriad varieties of ornamental roses are founded on a complex history of cultivation and crossbreeding among multiple wild rose species that stretches back more than 2,000 years in West Asia and Europe—and 5,000 years in China. In the New World, ornamental dahlias and marigolds, including double-flowered varieties (with multiple layers of petals), were developed by the Aztecs in Mexico more than two centuries before the Spanish conquest of 1521.
Flowers also feed our fascination with novelty. Something that is different is exciting and emotionally rewarding, and flowers from different parts of the world are perceived as particularly exotic. The trade in flowering plants in recent centuries has been so extensive that every gardening book and online resource is a cosmopolitan collage of modified plant life. We have become so familiar with garden plants that we need to remind ourselves that our backyards are a haven for the exotic. What’s more, some of these exotic plants ignore the boundaries of our gardens and spread uncontrolled across the land. The most pernicious invasive plants include species that are courtesy of the gardening trade. Kudzu, tree of heaven, and giant hogweed come to mind.
I do hope that words can create a floral fix for a February day before the first flowers of spring. If not, it isn’t so very long before the snowdrops, aconites, and crocuses brighten up our backyards; by April, we will be enjoying the real spring lilies in our forests, including the red and white trillium and the yellow trout lilies. If you can’t wait, there is always the option of a visit to the local florist.