It’s nearly winter, and those of you lucky enough to live near some beaches or mudflats probably enjoy gazing out over motley assortments of shorebirds like this one. Until you can get outside, though, cast your eyes over this photo and help us answer the question: How many species are in this photo? (Of course, we’d also like to hear which species you think are in the photo—and how you can tell.)

One thing I love about this kind of birding is there are always a few birds on view that draw your eye as either pleasantly familiar or at least easy to figure out. I can gauge the intensity of my bird watching partners by how long they’re willing to scrutinize the other birds, like those little inkblots at the top of the frame. I also love the stark contrasts in size. I always find myself surprised by how my mental picture of a bird’s size in isolation doesn’t stack up against reality when two birds are side by side.

So have at it! Let’s try to compile a complete list of species for this photo. And if we need to I’ll try and get one or two of the Lab’s eBirders to weigh in on those mirage birds at the top.

(Click the picture to sink your eyeballs into a larger version. Image by Birdshare contributor Robinsegg, taken October 4 in Utah. It’s a crop of a much larger image, with even more species in it. Spoiler alert: following the link will reveal some of the bird IDs in this picture.)

Birders visiting the New World tropics rarely have to wait too long before hearing male manakins at their leks. With a bit of careful creeping through the undergrowth, you’ll often find a bizarre gathering of the little fist-sized birds hopping, strutting, or sidling along their perches in the hopes of attracting a mate.

The soundtrack is no less weird: each species has a characteristic pop, snap, ruffle, or whir typically produced mechanically with their wings. No vocal cords required. (You can listen to a selection by searching the Macaulay Library for “manakin.”)

One species, the Club-winged Manakin of Ecuador and Colombia, makes a thin violin-like whistle by knocking its wings together behind its back. This bird is near to the heart of Kim Bostwick, curator of the Cornell University Museum of Vertebrates. In 2005 she used high-speed video to reveal how the bird does it: by rubbing a stiffened wing-feather tip across seven remarkably precise ridges set into the thickened shaft of the adjacent feather. (It’s this feather that gives the bird its common name.)

The flurry of vibration as the male bird flaps its wings produces a tone at 1500 Hz (pretty close to an F-sharp played 3/4 of the way up a piano keyboard). Listen for it in this video clip:

Now, in a paper just out this week, Bostwick and colleagues have found two unusual ways the manakin’s wings modify that feather-scraping-on-ridges sound. First, that thickened feather shaft picks up the vibrations and begins to resonate, making the sound louder much the way a violin’s body amplifies the sound of a bow against strings. Next, the researchers looked at other feathers up and down the bird’s wing. Using lasers to watch the feathers vibrate, they saw that even these “normal” feathers picked up the sound. They began to vibrate in phase, adding some harmonic effects to the sound and possibly making it louder still. That short, reedy sound you heard in the video is the complicated result of an entire wing (or two) working together.

Fascinatingly, they conducted the same test with close relatives—other manakins that don’t make wing sounds. Those feathers also tended to vibrate at 1500 Hertz, though much more weakly and not in phase with each other. That result hints at how evolution could have yielded the Club-winged Manakin’s sound, using as raw material an inherent quality of manakin feathers and slowly modifying it.

But what makes evolution head off in such oddball directions? It’s thought that manakins court acrobatically rather than vocally because of sexual selection, a branch of natural selection. Although playing the world’s smallest violin behind its back doesn’t help a male Club-winged Manakin find food or fend off predators, it does attract mates—so birds that are better at it pass on that ability to future generations. What’s neat about this process is that it puts females in a powerful position. So-called choosy females, by selecting certain abilities in males and ignoring others, actually drive the evolution of their species as much as external events do—even to the point of producing outlandish thickened feathers that work like a musical instrument.

Bostwick and her colleagues note that this kind of sound production is basically unknown among vertebrates. Plenty of insects do something similar called stridulation. The peaceful chirping of crickets on a summer night, for example, comes from hundreds of cricket legs rubbing against hundreds of hard cricket exoskeletons, amplified by resonating throughout their little cricket bodies. But among the vertebrates their only peer known so far is the Club-winged Manakin. As Bostwick and colleagues put it:

“The mechanism employed by male Club-wing Manakins crosses taxonomic boundaries and places these birds squarely among more arthropod-typical mechanisms of sound production…. The presence of these extremely rare traits in a bird highlights an arthropod-vertebrate convergence enacted by choosy females, with the structural features of the modified secondary feathers appearing to have been exaggerated from resonant characteristics that probably existed in the ancestral feathers.”

Of course, none of this answers the question of why the males don’t simply open their beaks, whistle an F-sharp, and have done with it. While they were at it, they could probably throw in some slides, a trill, or a crescendo, like a “normal” songbird. Except that apparently female Club-winged Manakins just don’t find that version of the sound attractive. And as any rock star, stand-up comedian, tap-dancer, skateboarder, footballer, or husband can tell you, that’s the whole point.

(Read more about Bostwick’s research in this 2005 BirdScope article and in this post by Carl Zimmer at Discover magazine’s blog. If you’ve never seen a manakin moonwalking, this clip from Nature is a must-see. Image by Kim Bostwick)

Back in April when we launched the new version of our All About Birds website, we picked 51 common species and gave them the full treatment: expanded ID and life history information, sound and video clips, related links, and lots of photos of each bird in all (or nearly all) its plumages.

But commenters fairly soon started asking us for more photos of the other 532 species in our online species guide—birds that aren’t quite as common but still come in a variety of plumages: juvenile, immature, male, female, breeding, nonbreeding, dark-morph, light-morph, rufous-morph, and so on. We had a stockpile of some of these photos that used to be on our website, but owing to our new database structure we couldn’t incorporate them at launch.

So today we’re glad to announce that we’ve restored all 1,000 or so of those photos (including about 60 new photos of nests and eggs) to All About Birds. They flow seamlessly into the new site’s photo viewer, which means you can enlarge each photo and scroll through the collection until you find the plumage you’re looking for.

This doesn’t mean we’ll stop adding photos to All About Birds. The incredible photographers in our Flickr group, Birdshare, have now sent us more than 27,000 photos to work with, and we’re still intent on incorporating them into the species guide for the benefit of bird watchers everywhere. In the next few days, look for updates to Gambel’s Quail, Evening Grosbeak, Pine Grosbeak, Pileated Woodpecker, Yellow-bellied Sapsucker, and other birds. Thanks and good birding!

(Image: Eastern Screech-Owl, gray form, Michael J. Hopiak/CLO. Thanks to France Dewaghe and Greg Delisle for handling the technical side of this upgrade.)

Thanks everyone for weighing in on our photo quiz! Meanwhile, halfway around the world on Mauritius, recordist Jon Erickson has been unpacking his bags and aiming his microphone at the tamarind tree in his yard. Here’s his first impressions of life in the middle of the Indian Ocean:

On the third morning after arriving on Mauritius, I woke up invigorated and refreshed.  Unfortunately, it was 2:30 in the morning.  Instead of fighting it, I decided to befriend the jetlag and put on a pot of coffee.

My wife and I are living in Flic en Flac on the western side of the island. The beach here sprawls along the coast, protected from the pounding of the Indian Ocean by a coral reef that lies several hundred yards offshore.  The beach is covered with European holidaymakers, but plenty of locals are present, too, underneath the myriad snorkels breaking the surface of the water.  Mauritius is well known for its mixture of cultures and religions, and it is not uncommon to see a group of Hindu worshipers offering flowers, clay idols, and coconuts into the ocean, or a Muslim woman snorkeling in full burka.

For a sound recordist like me, one unfortunate byproduct of this tourist town is the ever-present noise from vendors, taxi men, diesel trucks, scooters, barking dogs, etc.  But, at 2:30 in the morning, the noise is at bay.  I decide that this is a good time to check my equipment and see if everything survived the 25-hour flight from the States.

Bringing the various microphones and field recorders onto the patio, I focus on the massive tamarind tree hanging over our apartment building. During the day, birds create such a cacophony that even the diesel lorry with a punctured exhaust is in danger of being drowned out.  The primary ruckus-maker is good old Passer domesticus. But many of the island’s other species gravitate to the tree; the Madagascar Fody (pictured), Red-whiskered Bulbul, Common Myna, Spotted Weaver, and, to my surprise, a pair of macaque (monkeys). But right now, even the tree is silent.

Switching on the recorder and putting on the headphones, I am happy to see and hear that everything is working. Turning up the gain, I can hear some distant details that I wouldn’t be able to pick up with a naked ear:  some dogs barking near the beach, an impatient rooster, the waves hitting the nearby jetty.  The barking escalates and I begin to wonder what’s going on.  I decide to let my imagination run freely and dub this test recording “dogs chasing monkey.” Shortly afterward, I record my second masterpiece “monkey chasing cat.” Two recordings destined for my personal collection only.

With the equipment checked out and working, I start imagining the recording field trips to come. With erratic buses, expensive taxis, and the prospect of theft looming over any bike or scooter I might buy, there’s some planning to be done. I’m hoping the local conservationists in the Mauritian Wildlife Foundation can help out. Since the 1980s this foundation has been instrumental in bringing back many of the island’s endangered bird species from the brink of extinction, including the Mauritius Kestrel and the famed Pink Pigeon, which at one point numbered only 10 individuals. I am eager to meet with them to see, first hand, the work that they are accomplishing, and to ask some advice about my own project.

Outside of the more elusive endemics, the island is rich in interesting birds. My initial impression is that nearly any abandoned lot will reveal a decent number of species. Fortunately, I live near Black River Gorges National Park, home not only to the kestrel and Pink Pigeon, but also the Mauritius (or Echo) Parakeet, the Mauritius Cuckoo-Shrike, and the Mauritius Bulbul. It’s only a short bus ride followed by a 3-mile hike to the visitor center.

I’m hoping that, by the end of the week, I will begin producing some recordings that will rival “dogs chasing monkey” and “monkey chasing cat.”

We got such an enthusiastic response to our first photo quiz that we’ve decided to launch another one. This one’s certainly not a tricky-ID problem—few people would look at these two photos and see two closely related species requiring keen attention to detail to separate.

And yet, they aren’t your everyday species and, despite their bold markings, they can be somewhat hard to locate when flipping through a field guide. I only noticed their overall similarities as I was assembling our November featured photographer portfolio, for Matt Shellenberg (spoiler alert: other photos of these two species are identified there).

Wait a minute, I said to myself, these are two strongly marked brown, yellow, gray, and black birds with big beaks. Identifying them is pretty straightforward—but why? What is your brain doing to separate these two birds from each other and from everything else? What advice would you give to a beginner to nudge them toward the right part of the field guide? As I said last week, we’re thinking a lot about the process of bird ID right now, and we’d love to know how you get to your answers.

Not only that, but they’re two cool birds, aren’t they? Here’s a closer look.

Exhibit A:

Exhibit B:

Thanks in advance for your answers. We’ll post a roundup in a few days.

(This photo quiz is powered by Birdshare contributors Stephen Parsons, Greg Page, and Kaustubh Deshpande. [spoiler alert! the birds are identified on those pages too])

We’ve just launched a new online course about birds and behavior. Titled “Courtship and Rivalry in Birds,” it’s appropriate for all levels of interest and birdwatching expertise—anyone who’s ever seen a bird have an odd hop, wing-stretch, or squabble and wondered what it meant. The five-week course is taught on a rotating basis, and enrollment is open now for classes that begin November 11, 2009, and January 6, 2010.

The course covers territoriality, aggressive and courtship displays, and the fascinating field of sexual selection, all vividly illustrated with examples ranging from the familiar Red-winged Blackbird to New Guinea’s exotic birds-of-paradise.

The course takes students beyond book-based learning. It dissects the mercurial aspects of bird behavior with sound, video, interactive slideshows, simple online games, and conversations with scientists.

“You get the whole gamut—from birds you might see in your backyard to the most spectacular birds on the planet,” said course coauthor Kevin McGowan. “If you pay attention, there are a lot of things happening—you can look at small movements, see how movements are put together, and figure out what it all means”—all rendered beautifully onscreen with video from the Cornell Lab’s Macaulay Library.

Tuition is $295 for the five-week course. Cornell Lab members can enroll for $255 by calling 866-326-7635. Class sizes are small (15-35 students), so get your place early!

Jon Erickson is living on the island of Mauritius for the next nine months. While his wife pursues a Fulbright scholarship to study local children’s literature, Jon plans to explore the island, recorder and parabolic microphone in hand, gathering natural sounds for our ever-expanding archives in the Macaulay Library. Mauritius, a former French colony, is a tropical island in the Indian Ocean, east of Madagascar. It’s home to 81 bird species.

A teacher and writer with a degree in philosophy, Jon will appear on this blog every few weeks to report on what he’s been finding. Here’s a brief background from Jon himself:

At the age of eight, I managed to catch a cottonmouth in the pond behind my house with a piece of cheese and a rope.  I remember watching the writhing creature with fascination until my horrified mother pulled me away from an untimely death. Apparently her protection fostered love rather than fear for wildlife, and my interest continues to this day.

So when my wife won a Fulbright to study in Mauritius for a year, I thought about all the remarkable wildlife I might find on this small island. Apart from Mauritius being the famous home of the Dodo, I realized I didn’t know much about the country’s wildlife, and I wondered about how to share what I would be learning.

After some inquiries, I was contacted by Greg Budney, audio curator of the Macaulay Library, who asked if I’d be interested in recording wildlife sounds for the library while on the island.  This meshed well with another of my life’s interests; I am also a musician and have an extensive background in sound recording. After a trip to Ithaca to meet Greg and the wonderful staff at the library, the project was born.

So now, here I am in Mauritius with a bag of loaned recording equipment, some field guides, a map, and a book entitled Speak Mauritian Kreol in Seven Easy Lessons.  I hope that in the nine months my wife and I are here I’ll be able to make an extensive set of recordings for the library. I’m aiming for around half of the island’s 81 species, especially 10 endemics (most are highly endangered): Pink Pigeon, Mauritius Kestrel, Mauritius Cuckoo-shrike,  Mascarene White-eye, Mauritius White-eye, Mauritius Parakeet, Mauritius Fody, Herald Petrel, Rodrigues Fody, and Rodrigues Brush-Warbler.

But for now I have to get settled. So goodbye—or as they say in Mauritius, orevwar!

Last weekend our ace programmer, France Dewaghe, skipped out of Ithaca for Cape May to catch the tail-end of fall migration. Here at work, we had been thinking a lot about bird identification and the power of groups to hone in on IDs, even tricky ones. So when France came back with a memory card full of bird photos—in his spare time he’s also the reigning champ in the digital SLR category of the World Series of Birding—we thought we’d give you all a look at one of the most enduring of all ID problems.

Take a look at these two birds and leave us a comment about what you think they are. Are they the same species or different species? Different age or sex? What do you think they are, and what leads you to that conclusion? We’re interested in hearing from anyone out there, whether you’re an expert or just learning; whether you know the answer or just have a hunch.

Here are the images one by one, a little bigger. Both were taken October 25, 2009, at the hawk-watching platform in Cape May, New Jersey.

Exhibit A:

and Exhibit B:

Let us know if you like these bird quizzes and we’ll offer more from time to time (you can also check out the semi-regular Mystery Bird feature at GrrlScientist). And if you find all this bird ID confusing, check out our Inside Birding video series for easy-to-use tips on your technique.

(Images by France Dewaghe)

A new line of greeting cards lets you send an elegant piece of bird art and bring it to life with accurate sounds of the species on the front. The cards are a collaboration between an English company, Really Wild Cards, and the Cornell Lab of Ornithology.

Each card features a lovely bird painting taken from the Cornell Lab’s own art collection. When you open the card you’ll hear about 15 seconds of calls and song for that species, drawn from our comprehensive archives in the Macaulay Library. At present there are 14 species available (ranging from Common Loon to Yellow-headed Blackbird), with more cards slated for release about every six months.

You can order the cards through the Wild Birds Unlimited store in Sapsucker Woods (or call 877-266-4928). Visit the website to see all the artwork and hear the sounds for each card. A portion of proceeds comes back to the Cornell Lab to help fund our mission of research, conservation, education, and citizen science.

Birdsong fascinates scientists because it’s varied, beautiful, complicated—and because many birds learn songs in a way similar to how humans learn language. Studying the way young birds acquire their songs might allow us to solve problems with the way children develop language.

Much song research is done by watching young birds in captivity, but research just published today tackled the formidable task of following birds through field and forest. The approach gave the researchers a more realistic picture of how young birds behave. The scientists, led by grad student Chris Templeton of University of Washington, discovered that juvenile Song Sparrows are more interested in listening to two adult male Song Sparrows sing at each other than in listening to just one. That’s an exciting finding, because it suggests that the young birds don’t just mimic the sounds of a single adult. They listen to the way the two birds trade song phrases and types back and forth, perhaps learning the appropriate context for each phrase, or at least learning which song types are the most common in their neighborhood.

The researchers get extra points for effort. They set up experiments in a large, wild park in Seattle. Since they weren’t working with caged birds, they attached tiny radio-transmitters to 11 juvenile Song Sparrows so they could keep tabs on their whereabouts. In a series of experiments, speakers set up near each bird played the sound of either one adult Song Sparrow, two adult Song Sparrows singing at each other, or, as controls, the sounds of one or two Black-capped Chickadees. As the sounds played, the researchers kept close track of the young Song Sparrow’s actions. They found that the birds moved much closer to the speaker when it played two Song Sparrows than with any other recording. Their response to a single Song Sparrow wasn’t much different from their response to chickadee recordings—essentially mild curiosity rather than the keen interest they had in two birds conversing.

The research is only a few hours old, but it’s already appeared in a number of news outlets. Several of the stories tout the finding that young sparrows learn their songs, but what’s really exciting here is their interest in eavesdropping on an adult “conversation.” When people first started studying birdsong we thought of birds as tiny tape recorders that heard a song, then reproduced it as best it could. In the decades since then we’ve gradually seen how much learning and even improvising (in the case of mockingbirds, for example) goes on. Now it seems that even in their first few months of life, Song Sparrows are attuned not only to sound, but to social interactions that, as adults, they will have to navigate using their voices.

(Image: Song Sparrow by birdmandea via Birdshare; hear more Song Sparrows and see videos on All About Birds)

(Full disclosure: I knew Chris Templeton in grad school about 10 years ago, when he was a Master’s student working with chickadees. Way to go Chris!)