By Jason Martin and Robyn Bailey

In many parts of North America, handsome male Northern Cardinals are already singing to attract mates. A bird so visible in the winter landscape begs the question, “How does a flame-red bird that nests close to the ground manage to be so common?”

Many people puzzle over how this conspicuous species can be so successful, despite its low rate of nesting success. Typically, fewer than 40 percent of nests fledge at least one young. And if predation is a problem for cardinals, why don’t the males try to blend in a little more? Our NestWatch team has some answers, fed by details of cardinal nesting behavior gleaned from the 268 nesting attempts reported to the program so far. Here’s project leader Jason Martin:

The answer may lie in their long breeding season. Cardinals do not migrate and can begin building nests as early as late February. They can continue nesting into late August or September, giving them plenty of opportunity to raise one or two broods of young per year.

Another factor could be that cardinals are habitat generalists. They can nest in open woodlands, dry shrubby areas, disturbed tangles, suburbs, backyards, and even deserts. And they seem to put their nests pretty much anywhere: a recent study in Texas found that cardinal nest sites weren’t particularly different from sites the researchers chose at random. This suggests that cardinals may not be limited by suitable nesting locations.

Cardinals build their nests in live trees, shrubs, or vine tangles, anywhere up to about 15 feet high. Higher nests, and nests placed in denser tangles, seem to offer some relief from predators. The bright male carries nesting material to the female, who does most of the building. She uses her big beak to crush twigs until they’re pliable, then bends them around her body to make a nest cup that fits her, wedged into a small fork of branches for support. The nest is a sophisticated structure that takes 3–9 days to build. By the end, it’s about four inches across and three tall, lined with a snug layer of grapevine bark and fine grasses and pine needles.

But how does the male get away with being so colorful? The flamboyant males sing from high perches and do not trade their breeding plumes for a drab winter coat—they seem like obvious targets for hawks. It turns out that male cardinals are probably bright and loud for the same reason: to advertise what good mates they’d make.

According to the Birds of North America Online, brighter males have higher reproductive success, hold better territories, and offer more parental care. The intensity of a cardinal’s redness is related to what he’s been eating. So when females see a bright male, it’s a signal that he’s healthy and holds a good territory. (Interestingly, recent research by Amanda Rodewald, the Cornell Lab’s new director of Conservation Science, shows that this relationship may be getting less reliable for cardinals in urban areas, because of the novel food sources available in town.)

By responding to redness as a sign of a promising mate, females have encouraged the evolution of bright coloring in males. This process is called sexual selection, and it’s an everyday example of a process that can lead to extraordinary creatures like the birds-of-paradise. At the same time, the female’s muted colors provide her (and her nest) with a protective camouflage that the male lacks. Furthermore, cardinals tend to have high survival rates, possibly because they don’t endure the stress of migration. The oldest recorded cardinals lived to be at least 15 and a half years old (one recorded in Pennsylvania and another in Virginia).

If you are lucky enough to find a cardinal nest this year, won’t you help us learn more about this fascinating species? Last year, NestWatch participants monitored a record 81 Northern Cardinal nests. Can we get more in 2013? Head over to NestWatch for tips, stats, and focal species information, plus details about how to monitor nests safely as part of this great, free project.

(Image by Daniel Behm via Birdshare. This post was written by NestWatch project leader Jason Martin and program assistant Robyn Bailey.)

This post was written by Andrea Alfano, a Cornell University junior.

Would you pull over your car just to watch some starlings? A gathering of only a few of these speckled, iridescent-black birds isn’t a very alluring sight—particularly in North America, where these birds are invaders. The European Starling was originally introduced here by a group of well-meaning Shakespeare enthusiasts in 1880, but many Americans now consider them to be pests that serve little purpose other than to dirty car windshields and destroy crops.

But Grainger Hunt, a senior scientist at the Peregrine Fund, tells a different story in Living Bird magazine. He marvels at the way thousands of the birds gather in flocks called murmurations. They are “a dazzling cloud, swirling, pulsating, drawing together to the thinnest of waists, then wildly twisting in pulses of enlargement and diminution,” he writes. It’s certainly worth stopping your car for, or stopping to watch a video like this one, a YouTube hit recorded over the River Shannon, Ireland:

Almost always, Hunt writes, these aerial spectacles are caused by a falcon near the edge of the flock. It turns out that the beauty of a murmuration’s movements often arises purely out of defense, as the starlings strive to put distance between themselves and the predator.

So how do these masses of birds move so synchronously, swiftly, and gracefully? This isn’t an idle question—it has attracted the attention of physicists interested in how group behavior can spontaneously arise from many individuals at once. In 2010, Andrea Cavagna and colleagues at the National Council of Research and the University of Rome used advanced computational modeling and video analysis to study this question. They found that starling flocks model a complex physical phenomenon, seldom observed in physical and biological systems, known as scale-free correlation.

Surprising as it may be, flocks of birds are never led by a single individual. Even in the case of flocks of geese, which appear to have a leader, the movement of the flock is actually governed collectively by all of the flock members. But the remarkable thing about starling flocks is their fluidity of motion. As the researchers put it, “the group respond[s] as one” and “cannot be divided into independent subparts.”

When one starling changes direction or speed, each of the other birds in the flock responds to the change, and they do so nearly simultaneously regardless of the size of the flock. In essence, information moves across the flock very quickly and with nearly no degradation. The researchers describe it as a high signal-to-noise ratio.

This scale-free correlation allows starlings to greatly enhance what the researchers call “effective perceptive range,” which is another way of saying that a starling on one side of the flock can respond to what others are sensing all the way across the flock—a huge benefit for a starling trying to avoid a falcon.

Last week, a new study on starling flocks appeared in the journal PLOS Computational Biology. The researchers, led by George Young at Princeton, did their own analysis of murmuration images to see how the birds adjust to their flockmates. They determined that starlings in large flocks consistently coordinate their movements with their seven nearest neighbors. They also found that the shape of the flock, rather than the size, has the largest effect on this number; seven seems optimal for the tightly connected flocks that starlings are known for.

Imagine a game of telephone: one person passes a message along to the next person, who repeats it to another, and so on. For humans, the telephone message loses information very quickly—that’s what makes the game fun. The first finding, by Cavagna’s team, suggests that very little information is lost in a starling flock. The second finding, by Young’s team, suggests that starlings “play telephone” with their seven nearest neighbors. Somehow they are able to process messages from those seven neighbors all at once, and this is a part of their method for achieving scale-free correlation.

Still, neither finding explains how starlings are capable of such extraordinary collective responses. As the researchers admit, “How starlings achieve such a strong correlation remains a mystery to us.”

Murmurations remind us that nature’s beauty can take limitless forms, and can shock and inspire us. A number of commenters on the River Shannon video mention a feeling of connection that they experienced while watching the video. It’s as if seeing that synchrony, that seemingly perfect connection between each starling, also reminds us to value our connection to the world around us, for connection can be truly beautiful.

(This post was written by Andrea Alfano, a junior at Cornell University. Image is a collage of European Starling by simonglinn via Birdshare, and murmuration photo by ad551 via Creative Commons.)

Imagine you walk into the neighborhood coffee house for your morning cup of joe, and on the counter is a tip jar with a sign reading, “$ for wintering warblers” with a photo of a Chestnut-sided Warbler in a tropical forest.
You’d drop your change in, right? Any proud bird watcher would do their part for the wellbeing of the sprightly warblers that delight us so much come spring.

It’s not such a stretch of the imagination, York University researcher Bridget Stutchbury told a packed audience at the Cornell Lab’s Monday night seminar series last week. Many of the colorful songbirds that are just now leaving us for the winter, including warblers, tanagers, orioles, and grosbeaks, will spend the next five months in and around shade coffee plantations in Mexico and Central and South America.

But only if the birds can find them. Shade-coffee plantations—particularly ones that grow coffee under a natural forest canopy—are increasingly being deforested, leaving North American migrants with fewer places to spend the winter. The good news, Stutchbury said, is that you can have your dark roast and your songbirds too if you buy sustainable coffee, particularly Bird Friendly coffee.

Stutchbury recapped recent research on Wood Thrushes, sweet-singing birds of Eastern forests whose numbers have dropped by half since the 1960s. Yet, with regenerating forests in the Northeast, Wood Thrushes now have more breeding habitat than they did decades ago. “What does that tell you?” Stutchbury asked her audience. “Must be a problem on their wintering grounds.” (Although some researchers point out that the quality rather than quantity of forest in North America might still be limiting this species.)

And indeed, when Stutchbury tracked individual Wood Thrushes from the U.S. to Nicaragua and back, she found that regional Wood Thrush population declines matched deforestation trends in Nicaragua, where forest cover has dropped 30 percent in just the past two decades.

This deforestation likely affects other wintering songbirds, too, such as Baltimore Orioles and Chestnut-sided and Kentucky warblers, which have also declined in the last half-century, according to the North American Breeding Bird Survey.

Can shade-grown coffee help these birds? Most coffee drinkers figure the answer is yes. But as it turns out, the words “shade-grown” on a package of coffee can refer to a range of habitat conditions that offer varying degrees of refuge for migratory songbirds.

Making Sense of Sustainable Coffee Labels
They’re those little rectangular icons lined up on your favorite gourmet coffee bags—a tree, a flower, a frog, a harvester, each trying to tell you something about how the coffee was grown. But what does each one mean, and how do they differ? Here’s a list of common labels and their benefits for birds. For more specifics, see the list of links below.

Bird Friendly. Certified by scientists from the Smithsonian Migratory Bird Center, this coffee is organic and meets strict requirements for both the amount of shade and the type of forest in which the coffee is grown. Bird Friendly coffee farms are unique places where forest canopy and working farm merge into a single habitat. By paying a little extra and insisting on Bird Friendly coffee, you can help farmers hold out against economic pressures and continue preserving these valuable lands. The good news is that there’s more Bird Friendly coffee out there than many people realize—we just need to let retailers know we want it (see below).

Organic. As with other organic crops, certified organic coffee is grown without most synthetic pesticides and fertilizers and is fairly sustainable—although there are no criteria for shade cover. Because of coffee’s growth requirements, it’s likely that organic coffee has been grown under some kind of shade. However, many farmers shade their coffee using other crops or nonnative, heavily pruned trees that provide substantially less habitat for birds, and the organic label offers no information about this.

Rainforest Alliance. The most popular environmentally friendly certification for coffee as well as tea, cocoa, and fruits, Rainforest Alliance requires alternatives to chemical and pesticide use (though they stop short of organic certification), erosion control, restricted water use, and ecosystem management efforts. Because Rainforest Alliance develops standards for a wide range of farms, their shade-cover requirements are not as demanding as Bird Friendly coffee. Also, Rainforest Alliance allows coffee blends to be sold with the Rainforest Alliance label even if only a percentage of the beans (currently only 30 percent, with plans to scale up to 90 percent) carry the certification. Rainforest Alliance has a laudable goal to make a difference on a fairly large scale (they certified 540 million pounds of coffee in 2011), but there is no guarantee their certified coffee farms meet the wintering needs of migrant songbirds.

Fair Trade. Inspired by humanitarian concerns, Fair Trade labeling helps to ensure that the workers on coffee farms get paid fairly for the work they do. The higher prices that Fair Trade products earn help to provide an alternative to the price leverage that large coffee buyers can wield. However, a Fair Trade label does not automatically indicate that any environmentally friendly practices were followed.

Shade-grown. “Shade-grown” labels often appear on specialty coffees, but unfortunately this designation is not regulated and doesn’t tell you much about the growing conditions at the farm. When the idea for Bird Friendly coffee was hatched by the Smithsonian Migratory Bird Center in 1996, plans for the certification process faltered while coffee companies quickly adopted the term “shade-grown” as a marketing buzzword. Unfortunately, this type of coffee can be grown among sparse trees on farms that lack diverse forest structure. Some shade-grown coffee is even grown under only the flimsy cover of banana trees fed artificial fertilizers and pesticides.

Sun-grown. Most coffee grown at an industrial scale is grown under full sun. Acres upon acres of coffee bushes planted in hedge-like rows are sustained by fertilizers, pesticides, and irrigation. If a coffee brand bears no labels at all, it is likely produced with these methods and is unsustainable.

Bird Friendly Farmers Offer Half a Solution—We Can Be the Other Half
Bird Friendly certified coffee can be hard to find on store shelves and in coffee shops. One reason is that the standards for certification are so rigorous that only a small fraction of coffee farms can qualify. The total amount of Bird Friendly coffee certified in the past 12 years amounts to less than 2 percent of the Rainforest Alliance–certified coffee in 2011 alone.

But there’s another, paradoxical reason: coffee sellers don’t always advertise that their coffee is Bird Friendly. “Probably about only 10 percent of coffee from Bird Friendly certified farms carries the Bird Friendly stamp on the package,” said Robert Rice, a research scientist at the Smithsonian Migratory Bird Center.

For example, Starbucks and Whole Foods sell some coffee from Bird Friendly certified farms. But they don’t see the need to make room on their packaging for a separate label that appeals to a relatively small—and silent—minority: birders. And without the consumer demand and higher prices for Bird Friendly coffee, past history in Central America suggests that the market pushes coffee farmers toward partial-shade and sun-grown practices.

That’s understandable, said Stutchbury. “We can’t demand that they don’t cut down their forests, and give up money, unless we’re willing to give them something as compensation,” she said. That’s the central idea behind Bird Friendly certified coffee: paying a price premium to growers on rustic coffee plantations so that they can continue to provide prime bird habitat.

The good news is, birders can make a difference—by asking retailers to stock Bird Friendly coffee, and by buying it. Think of it as a tip jar next to your coffee maker. More than 46 million Americans say they watch birds, and half of all Americans drink coffee. “If every birder in the U.S. committed to drinking Bird Friendly coffee, the market would grow 1,000-fold,” said Bill Wilson, owner of Massachusetts-based Birds & Beans, an online coffee retailer that specializes in selling only Bird-Friendly coffee.

Stutchbury closed her talk on Monday by saying it’s time for birders to assert themselves in the coffee marketplace. “Buying Bird Friendly coffee is one of the best ways you can do your part to preserve wintering habitat for our migratory songbirds,” she said.

Where to buy Bird Friendly Coffee
Grab a supply of Bird Friendly coffee with the help of these Smithsonian Migratory Bird Center pages:

• Find a store near you
• See a map of stores that carry Bird Friendly coffee
• Order Bird Friendly coffee online

More resources on coffee and bird habitat

• For much more detail about coffee labels and their meaning visit the Coffee and Conservation blog, operated by University of Michigan biologist Julie Craves.
• Not all coffee retailers advertise that their coffee is Bird Friendly. If you’re unsure whether your favorite coffee source is Bird Friendly, you can check this list of certified Bird Friendly farms organized by country.
• The Committee for Environmental Cooperation is a joint effort by the governments of Canada, Mexico, and the United States. They provide background on sustainable coffee and a wealth of information and research.

(This article was written by Cornell Lab science editor Gustave Axelson. Image: Hugh Powell.)

On the eleventh anniversary of 9/11, twin spotlights once again shot into the night sky above Manhattan to offer a tribute to the men and women we lost during the 2001 attacks.

It was a clear and cool night, almost calm and with a hint of a southerly breeze. In another long-repeated annual event, thousands of birds passed over New York City on their way to winter homes in the southern U.S. and Central and South America. Cornell Lab scientist Andrew Farnsworth was on hand to count them.

Farnsworth spent the early evening until about 10:00 p.m. atop the Empire State Building and then watched from the Tribute in Light itself until 12:30 a.m. (accompanied by other birders and a Wall Street Journal reporter). In all he saw at least 2,000 birds and heard the faint chip notes of many more. He identified 28 species passing overhead and at times flying through the beams of light, where the rush of bodies looked like flurries of snow, he said.

Watching carefully with binoculars, he was able to identify a bewildering diversity of the tiny, 5-inch songbirds as they passed through the beams, recording Magnolia, Chestnut-sided, Black-and-white, and Blackpoll warblers, as well as Common Yellowthroats, Ovenbirds, Northern Waterthrushes, and 43 American Redstarts. Five male Black-throated Blue Warblers were still in such bright plumage that they “stand out like a sore thumb in the lights,” he wrote in his eBird checklist for the night. He also recorded Wood Thrushes, Swainson’s Thrushes, Veeries, Rose-breasted Grosbeaks, Gray Catbirds, and Baltimore Orioles.

The lights illuminated a few larger birds as well, including a young Laughing Gull that was trying to catch insects, three Green Herons, an unidentified rail (likely a Sora)—as well as a Peregrine Falcon that made repeated hunting dives at the smaller birds. Farnsworth said he saw at least five successful attacks on warblers.

The Tribute in Light happens during a time of peak migration in the Northeast. The birds often become briefly disoriented in the lights, and most years the lights are briefly shut off throughout the night to allow circling birds to reorient themselves. This year, on a night with only moderate migrant traffic, Farnsworth saw no evidence of casualties (aside from the peregrine’s catches).

The Tribute serves as a double reminder: that city lights, when left on en masse, nationwide, for an entire migration season, take a major toll on migrating birds (see the Fatal Light Awareness Program for more); but also, of the great spectacle of bird migration that accompanies us through fall. An invisible river of animals, rivaling any scene from the Serengeti but consisting of half-ounce birds that pass quietly overhead, in the dark.

Farnsworth is a lead scientist in our BirdCast project. Its ambitious goal is to produce accurate, real-time forecasts of local migration by combining data from radar, weather conditions, and acoustic recordings of the birds’ own brief call notes, which can be identified to species. While it will be a boon to anxious birders wondering what might turn up near them (you can check predictions at the BirdCast website), BirdCast also aims to provide advance knowledge of hazardous conditions at wind turbines so they can reduce their impact on birds.

The project is still in its first year, although researchers have been applying technology to the study of migration for decades. Weather radar is good at detecting flying birds, even allowing Farnsworth to estimate the numbers of birds aloft on Tuesday night, for instance. Judging by the radar readings, he said, one cubic kilometer of New York City sky probably contained 100–200 birds at any one time on September 11. That’s not bad, according to Farnsworth, but the two previous nights had been even better, when some 600–1,000 birds filled the same volume of sky. They were audible even over city noises—cars in the Brooklyn Battery Tunnel, sirens, construction work—the birds’ short, sibilant call notes raining down at the rate of 3 to 5 per second at times.

Which brings up a third reminder from the Tribute in Light: if dozens of species, and thousands of birds, routinely pass over a metropolis in pitch darkness, night after night, then doesn’t that make autumn one of the most exciting times to be a bird watcher?

BirdCast is funded by the National Science Foundation and the Leon Levy Foundation, and involves partners at the Cornell Lab, Microsoft, the National Oceanic and Atmospheric Administration, and the University of Massachusetts at Amherst.

(Image by Greg Chow via Creative Commons.)

Just last week was the North American Ornithological Conference, a major gathering of ornithologists in Vancouver, British Columbia. Quite a few of our staff and scientists attended, and among them was Wes Hochachka, assistant director of our Bird Population Studies program. When last we heard from Wes, he was extolling the virtues of European warblers—but this time he happened upon a presentation about hormones, migration, and a couple of American warblers, and it got him thinking. Scientific conferences are packed with talks, lectures and poster sessions, each one offering a new insight or discovery—here’s Wes with one example:

I’m here at the fifth North American Ornithological Conference, and I have a problem… mind you a rather nice problem. With the conference’s size (an estimated 1,500 attendees) comes the problem of too much choice. When I’m not meeting and talking with friends and colleagues old and new, I have to choose which of 10 parallel presentations I want to see. On a number of occasions I’ve had to make a decision to see one presentation while wishing that actually I could also see a second in another conference room somewhere else on the campus of the University of British Columbia.

At other times, like this morning, I’ve found myself at loose ends and wandered into a lecture room on the spur of the moment because a talk’s title struck me as interesting. In this case, the speaker was a graduate student, Kristen Covino, of the University of Southern Mississippi, and she was talking about her research at the junction between ecology and physiology.

Covino was looking at the way testosterone concentrations change in birds over the course of spring migration. Now, when I think about testosterone’s role as a hormone, I think of how it affects aggression, increases muscle mass, and other stereotypically “masculine” traits. However, both males and females produce testosterone, and it plays many essential roles in a bird’s body.

Many of these are related to migration: birds preparing for a season of long, nonstop flights have to add muscle mass, control their deposition of fat (their key fuel source), and “decide” when it’s time to start migrating. Testosterone also spurs male birds to sing, which is the reason why you may hear migrating birds singing well before they have arrived on their nesting grounds—an obvious indication the hormone is starting to circulate in higher concentrations.

However, to date, no one has asked whether a burst of testosterone triggers migration and all of its accompanying changes, or whether there is a gradual buildup of testosterone as birds, particularly males, travel northward in spring. Kristen and colleagues took a geographic approach to this question: they caught migrating Magnolia Warblers, Northern Waterthrushes, and Swainson’s Thrushes in southern Lousiana—still many hundreds of miles from their breeding grounds—and took a tiny blood sample to determine their testosterone levels. Then the scientists headed north to coastal Maine to do the same set of tests on birds that had nearly completed their migratory journeys.

What Covino found was that there was no simple and single pattern. Magnolia Warbler males and females had identical levels of testosterone in the bloodstreams, and these levels increased as the birds traveled northward. For Northern Waterthrushes (another warbler species) males had higher levels of testosterone by the time they reached Maine, but females didn’t. Testosterone levels were low and unchanged for Swainson’s Thrushes.

So what about this inconclusive result caught my attention? Findings like this are exciting to me because they tell us that these birds are not simple mechanical objects that all do the same thing. Instead, they’ve evolved to display clearly different responses to the same (hormonal) stimuli. And more generally, to me findings indicate that birds possess enough flexibility in their physiological makeup to adapt to changing conditions. By heightening or dampening the way their bodies respond to changing hormone levels, these birds may be able to adapt to some of the novel changes in the world around them over the years to come.

For more stories from scientific meetings, see our archive.

(Image: Magnolia Warbler by dwaynejava via Birdshare.)

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  A Great Horned Owl spotted during daylight was a highlight.

  

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  The group saw many breeding warblers, including this Chestnut-sided Warbler.

  

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  The weekend included tours and hands-on practice inside the Cornell Lab.

  

Our fourth annual Young Birders Event brought together 10 expert young birders for a long weekend at the Cornell Lab in July. In addition to touring our favorite local birding spots, the high-school-age students met many of our scientists and graduate students to learn about how to turn an interest in birds into a career in science and conservation.

Each year we’re amazed not just at the enthusiasm but also the skills and experience these young birders already have. Several of them run their own blogs (here’s a post about the event from young birder Marcel Such, from Colorado). We asked Sayed Malawi, a rising junior from northern Virginia, to give us a description of the Young Birders Event from his own point of view. Here’s Sayed:

Standing at the edge of a scrubby patch of trees, Chris Wood was coaxing a rarity into view. The small bird, hidden by leaves and branches, chipped enthusiastically as it moved. Here and there I saw a leaf twitch or a twig shake as it made its way closer. Two adults and 10 teenagers waited, many of us hoping to get a glimpse of a life bird—a bird we’d never seen before.

Suddenly the Mourning Warbler appeared on an exposed log, offering a drop-dead look to myself and the other 11 people watching from just a few feet away. For a moment, it hesitated, as if it was so startled by the 12 humans that a few gray feathers had grown on its already silvery head. Then it was gone, chipping its way deeper into the brush.

The excitement of the moment took a little longer to dissipate. “That was my 350th,” said one teen from New Jersey. “As Mourning Warblers go, that was a really good look,” noted a more experienced birder from Connecticut. My own North America list isn’t quite at 350, but I was still happy with my lifer. After a little while we left the warbler in peace, and moved on.

It was an unusual occasion for an unusual bird. During the weekend of July 21, I traveled to the Cornell Lab of Ornithology with nine other aspiring young ornithologists hoping to learn how to take our interest in birds to the next level. I was taking part in the annual Young Birders Event, a weekend hosted by the Lab to expose a few lucky teens to a variety of careers involving birds. We were supervised each day by Chris Wood and Jessie Barry, Cornell Lab project leaders for eBird and the Merlin online identification project, respectively.

Birding with Chris and Jessie is something of a humbling experience. It’s not just that they can pick out a Canada Warbler chip note or a Pectoral Sandpiper several hundred yards away. The way that they are able to explain bird identification to those with much less experience is remarkable. I still don’t think I would be able to find that Pectoral, but I’m pretty sure I’d recognize it when someone else points one out. The highlight for me, though, wasn’t a warbler or a sandpiper; it was a Great Horned Owl seen in daylight. It appeared to have an injured eye, which turned its menacing blink into a charming wink.

Later the same day, we visited a special place to get even closer to a large variety of warblers: the Cornell University Museum of Vertebrates, housed at the Cornell Lab. Led by Dr. Irby Lovette, director of the Lab’s Fuller Evolutionary Biology program, we explored Cornell’s specimen collection. We touched briefly on amphibians and fish, then made our way to the birds for an exercise in warbler phylogeny. Our goal was to organize a variety of warblers by placing them in groups on a phylogenetic tree, or putting them with their closest relatives. My group made a mistake with the American Redstart and Painted Redstart; despite their similar appearance, they are in fact not very closely related.

Nevertheless, I still feel pretty good about deducing that the Olive Warbler should come before the Yellow-breasted Chat on the evolutionary tree. Ornithologists are constantly revising our understanding of birds’ evolutionary relationships, and some of that work is done right here, in the Lab’s own PCR (polymerase chain reaction) lab. Here, Lab scientists analyze DNA in mediums like blood samples. Some of the discoveries made through this method lead to changes to the official American Ornithologists’ Union check-list, and eventually in the field guides we all carry. (One recent example is the removal of the beloved warbler genus Dendroica, which happened when those species were reclassified into Setophaga).

For some people, having the rare opportunity to explore the drawers in the bird collection was the highlight of the Night at the Museum. While I did have a good time roaming the collection (especially when I found a specimen of a Wallcreeper, a little-known creeperlike species I’ve always wanted to see—it makes its home on sheer cliffs at high elevations in Europe), I found the applications of the Lab’s collection even more interesting. In addition to the PCR lab, the Lab houses an ancient DNA laboratory, which can be used to analyze the genetic information from a tiny piece of a specimen, even ones that are centuries old.

More than anything else, I came away from the weekend with a broader view of what ornithology means today. The study of birds has evolved far beyond shooting specimens and even simply looking at them through a lens. Somehow, over the two days I spent at the Lab, I realized that a career with birds could mean studying them in the field, recording their sounds or images, building a computer program, or educating others. It’s comforting to be reminded that I’ll be able to learn about birds no matter which of these paths I choose.

(Images by Sayed Malawi. For more information about the Young Birders Event, contact Jessie Barry at jb794@cornell.edu)

It couldn’t have arrived in better style: Liron Gertsman, a keen young birder from Vancouver, British Columbia, reported an American Robin along with 23 other species as part of his standard bird watching routine. That’s exactly how we want people to be using eBird—to keep records of everyday sightings. In addition to maintaining a complete history of your own personal birding journey, those records combine to provide a comprehensive picture of birds across the continent, and ultimately the world.

To celebrate the achievement, the eight members of the eBird team are assembling a prize package of specially chosen gifts to send to Liron. They’ve also selected one eBirder at random to receive a prize package, and that award goes to Wisconsin birder Chuck Heikkinen (whose winning checklist included Whooping Cranes, Buff-breasted Sandpipers, and more).

Congratulations Liron and Chuck! And thanks to everyone who submits observations to eBird. Because of your efforts, we are building one of the largest environmental databases in existence. Read more about both winners (and their prizes!) on the eBird site.

(Bird photos by Liron Gertsman; photo of Liron by Andre Chan.)

A highly accomplished group of young birders will gather here at the Cornell Lab this weekend for our fourth annual Young Birders Event, sponsored this year by Carl Zeiss Sports Optics.

Their agenda is packed with opportunities to go birding—but they’ll also spend time inside, learning about bird-centered careers from professional ornithologists and students here at the Cornell Lab. They’ll get to try their hand at recording birds in the field with professional sound and video equipment; and they’ll learn from our experts about Neotropical birds, taxonomy, the night-flight calls of migrants, and the art of field notes and sketches. (Read more about the 2010 and 2011 events.)

Admission to the Young Birders program is competitive, and enrollment is limited to 10 students each year. In their applications, this year’s 10 expressed a common theme: their hunger for contact with others their own age who are as passionate about birds as they are. “Birds are what I think about during the day and what I dream about at night,”  wrote one eleventh-grader from Ohio.

Each of the teens has something else in common—they’ve put their passion into action. Many are already licensed bird-banders, lead bird tours, or have set up birding clubs for young people in their area. They are dedicated eBirders, submitting observations to the online checklist program, sometimes on a daily basis. They run birding blogs, write for birding newsletters, and take their own pictures of birds.

And they have big dreams. They want to be field researchers, become involved in wildlife conservation, or teach. They are fascinated by bird diversity, flight, and sound. They have favorites: gulls, owls, warblers. They are as diverse as the birds they love but united in their profound attachment to birds. In some cases, birds have been a bridge to normalcy in the face of injury or illness.

“Many times I was overwhelmed by the task before me and what I was bound to face,” says a Connecticut ninth-grader dealing with serious health issues. “Birds were my allies. I had so many experiences where I was reminded how special life is and how I must fight for mine every day, just like the birds do.”

“These young birders will be the next generation of leaders in ornithology and conservation,” says the Cornell Lab’s Jessie Barry, one of the hosts of the event. “Though we started this event in 2009 as a way to connect young birders with each other and inspire them, we come away just as inspired by their passion and enthusiasm.”

If you know of a promising young birder in grades 9 through 12, tell them about the Young Birder’s Event and have them contact Jessie Barry at jb794@cornell.edu to find out more about the 2013 session.

Science editor Gus Axelson is just back from a tour of eastern Hungary sponsored by Swarovski Optik. (Look for his story about bird conservation in Hungary to appear in a future issue of Living Bird.) As Gus returned to the world of American Redstarts and other brilliant warblers, he turned his attention to a more basic question: what’s with the drabness of the European warblers? Here’s Gus:

I suppose one could say that brownish European warblers are no different than our sparrows—differentiating a Savannah from a Song from a Lincoln’s sparrow can be tricky if you rely on field marks alone. But c’mon, these are WARBLERS. Some of the most cheery, dazzling, brilliant participants in spring’s migratory parade!

Europeans have a different opinion. Dale Forbes, an Austrian, argued on 10,000 Birds last year that “real” warblers are brown, and our warblers are little more than “silly canaries.”  (Although it took only one wood-warbler extravaganza at Magee Marsh this past May for Dale to reconsider his position).

Personal opinions aside, there’s an interesting evolutionary question here. Warblers on either side of the Atlantic aren’t making a fashion choice in their plumage (“Should I wear yellow or brown before Memorial Day?”). Is there some kind of competitive advantage for warblers being brown in Europe and colorful in North America?  I posed that question to Irby Lovette, director of the Fuller Evolutionary Biology program here at the Cornell Lab (and leader of a project that mapped the wood-warbler tree of life).

Irby quickly pointed out that though both groups are called “warblers,” they’re not particularly closely related—so you wouldn’t necessarily expect them to sport similar plumages. Europe’s warblers are all in a superfamily, Sylvoidea, while North America’s all belong to the family Parulidae. That’s why your field guide places the few Old World warblers that show up in North America (like the Arctic Warbler) near the kinglets, and far removed from “our” warblers.

Taxonomic worries aside, Irby was still willing to offer an explanation:

“So scientifically we have to just consider why some birds are drab and others are brightly colored. The reason our wood-warblers are more colorful has to do with various forms of sexual selection. Our male warblers use their bright plumage as symbols of status. Consider the American Redstart. First-year males are more drab, but adult males are brightly colored, and they get the best territories. Colorful male plumage is also beneficial in attracting females. And when you look at our female warblers, they tend to be more drab.

“So, why are European warblers drab? Well, they accomplish the same thing, males compete with other males and attract females, but they do it through their songs instead. They tend to be prolific songsters. So European warblers just chose a different type of communication.”

(And indeed, the Euro birders on the trip bragged their warblers were superior singers.)

Even though I prefer my warblers to be bright and cheery, I will concede that the subtleties of European warblers necessitates better technical ID skills. On my Hungary trip, the British contingent of birders were adept at using setting, posture, behavior, and song in identifying birds, and they relied on field marks only as supporting evidence. That’s also the gist of our Inside Birding video tutorials, in case you’re interested in brushing up on your own skills.

For me, one final anecdote from the trip sums up the debate. After birding in Hungary’s Bükk National Park one day (where I racked up Eurasian Treecreeper, Marsh Tit, Rock Bunting, and Hawfinch), I sat down for a cold Soprani beer with the European birders. A Swede named Per Göran Bentz told me he had a photo of his favorite warbler on his credit card. He opened up his wallet, took out the card, and showed me a striking image of a Blackburnian Warbler.

• Do you agree or disagree? Read the second post in this series: Counterpoint: 7 Ways European Warblers Outperform American Warblers

(Images via Birdshare: European warblers at left: Arctic Warbler by Bill Thompson; Common Chiffchaff by Etienne Littlefair; North American warblers at right: Blackburnian Warbler by Danny Bales; Prothonotary Warbler by A wing and a prayer.)

How much of the world we see around us is the result of competition between species? The answer is one of the enduring debates in the field of ecology. Evolution and natural selection are founded on the idea that individuals compete to get the resources they need to survive. It happens within species all the time, but whether competition happens between members of different species has been harder to ascertain.

The question is the subject of a new book, Interspecific Competition in Birds, published by Oxford University Press. The author, André Dhondt, is the Morgens Professor of Ornithology at the Cornell Lab. In a recent conversation, he described how the book developed from his early work on two common species of tits, small European songbirds that look like colorful chickadees.

Q. For a person watching birds squabbling at feeders, it seems like competition among species happens all the time. Can you explain why that might not be proof of competition?

A. There’s a fundamental difference between competition and aggression. For an interaction to be called competition, it must have adverse effects on survival and reproduction for the individuals involved. So in order to prove the existence of competition, detailed and extensive data on survival or reproduction are required.

Some people believe that competition is so important in nature that when it occurs it will be transient. Either one of the species will disappear or the two species will evolve rapidly such that they avoid competition. This was the paradigm actually for a very long time, saying that two species that compete cannot coexist. This led to “the paradox of competition”—the idea that competition is so important that it can only rarely be observed.

Q. So this idea held sway for many years, and then what happened? How did it lead you to write this book?

A. Well in 1977, by analyzing some data that we had in Belgium, I found evidence for competition between Great Tits and Blue Tits. When the density of one species was higher, the reproduction of the other species was less. The Blue Tits, being smaller, eat the younger instars of the caterpillars, so they eat the caterpillars before the Great Tits can start to eat them. The more Blue Tits there are, the less food there will remain for Great Tits.

At that time [this] was against the accepted idea, so much so that it got published in Nature. And actually this was the start of a large number of studies both in Europe and North America looking in more detail at the existence of competition, a lot of it experimental.

[In the 1990s] I was invited to give a plenary talk about my work on competition, and after the talk one of my friends and colleagues, John Krebs, who also studied Great Tits for a large part of his career, came to me and said, ‘Gee André, have you thought about writing a book about this?’ And the answer was no, I never thought about writing a book, period. But I said, you know if there were a book I would write, it would be about this subject.

Q. So for many years people thought competition was rare among species, and then your work started people thinking it wasn’t so rare. Does the book take sides?

A. The real question in this book is, does competition exist? If so does it exist frequently or is it rare? Just because you can prove it exists in one system does not mean that it is generally important. Finding it does exist, then I ask the question, okay what’s the effect as a selective force on traits of species? I try really to find the examples in the world today that document rapid evolutionary changes caused by interspecific competition.

Q. And I take it there were plenty of examples, one even including humans?

A. It’s actually surprising, in the last 10 years, how many really good field experiments have been done. It’s hard to study a system in which you manipulate the intensity of competition over time and for long enough to cause evolutionary change. To some extent it’s the coming of age of field ecology, where the requirements for an experiment in the field are as rigorous as requirements for experiments in the lab.

I have a whole chapter, maybe 80 pages in the book, in which I summarize and discuss all the good field experiments [meaning they include replicates and controls] where people have tested for the existence of interspecific competition. That’s a list of about 100 experiments that I discuss.

One example is how we have outcompeted Neanderthal man. The thinking is that this was caused by global warming at that time, between the ice ages, and that modern man was able to use resources more effectively and thus outcompeted Neanderthal man. It was a fun paper to find.

Q. One reviewer has said of your book that you “seem to revel in the complexity of avian interspecific interactions.” Do you agree? Is a complicated answer more satisfying to you than a simple answer?

A. [Laughs.] Well, I like to understand things in detail. I like simple answers, but sometimes the answer can’t be simple. There are so many things interacting at the same time that if you limit yourself to a subset you might actually draw incorrect inferences. At some point you really have to go all the way and try to see what it’s like.

Q. Where does the field go from here? What’s the next question to answer?

A. What we need to do is to repeat some experiments but collect more detailed information. There’s a bunch of excellent work done in British Columbia [led by Kathy Martin at the University of British Columbia], who looked at the effects of competition in the whole cavity nesting community, which includes insects, mammals, and birds. But what she didn’t do was to follow the fate of individuals. So to understand really how the system works you would need to have like five times more people, so that you can [band] all the birds, so you can follow the fate of the individuals and their offspring. That would be I think the next breakthrough in this kind of research.

(Image: Blue Tit by Carolyne Barber via Birdshare)