"Officers, life doesn't have to be ugly. See, look at the birds out there. Listen to their call: 'Oo-wee! Oo-wee! Oo-wee! Oo-wee!" — Beverly Sutphin, Serial Mom
Alas, as fans of John Waters' masterpiece know, Beverly's love of her feathered friends didn't extend to homo sapiens. She even killed her dentist and his wife after spying on them eating dinner and pulling roasted bird apart with their fingers. Those monsters! Clearly they had to go. But she's absolutely right that bird calls are something special, which is why bioacousticians and other scientists spend a lot of time in the field recording ornithological utterings and than analyzing those recordings back in the lab.
I was reminded of this by Ed Yong's recent post on the intricate song stylings of the lowly plain-tailed wren — namely, that the males and females of the species engage in lilting duets with one another. That's the finding of Johns Hopkins researcher Eric Fortune, who has studied the birds in the wild to learn more about how each bird's brain circuitry encodes the entire song, although when they sing alone, they still include the same gaps in the melody that a partner would normally fill in. Read Ed's post for the gory details.
Birdsong — or more technically "vocalizations" — is also one way that diehard birdwatchers identify different kinds of birds in the field, along with the more traditional visual markers, especially since some of the rarer varieties prefer to be heard rather than seen. 
It has always been thus for birdwatchers, many of whom prefer the term "birding" because of the aural element involved in the practice.
Jen-Puc Piquant recalls a line from the Merry Wives of Windsor: "She laments sir… her husband goes this morning a bird-ing." I suspect that context indicates hunting, however, since Wikipedia informs me that the first written record of watching birds because they're, like, pretty and stuff (as opposed to shooting them for food) dates to the late 18th century, in the writings of Gilbert White and John Clare, among others.
Even then, it was as much about collecting specimens from around the world for the enthusiasts' private collections as anything else. The term "birdwatching" doesn't appear in print until 1901, when Edmund Selous published a book by that title, although the first field guide dates back to 1889: Florence Bailey's Birds Through an Opera Glass.
Today, birdwatching is more than just a hobby, it is a vital industry. Per the U.S. Fish & Wildlife Service, some 46 million enthusiasts spent $32 billion on their hobby in 2001 alone — and that's just in the United States. Birdwatchers invest in a lot of technical toys, although it does make for carrying a lot of unwieldy equipment into the field: binoculars, a recorder, a field book, CDs, and MP3 player, cameras, tripods, not to mention food and water for the human observers.
The science has also exploded in this area. Between 2005 and 2006, bioacousticians published more than 1700 papers on a wide range of animal sounds, including birdsong. Thanks to that avalanche of research, these days there's lots of audio resources available to birdwatchers, including catalogs of hundreds of different bird songs, so that no one person needs to memorize all of them, like those poor Victorians.
But how do you take written notes on the sounds that birds make? Sure, you could use conventional musical notation, but many birdwatchers aren't musicians. Acousticians use sonograms, a kind of graphical representation that's great for research purposes, but doesn't really capture the essence of what the birdsong really sounds like. We're left with attempting to represent the songs phonetically, as in the quote from Serial Mom at the top of this post ("Oo-wee! Oo-wee!"). Field guides often resort to vague phrases like "far-carrying melancholic song," or the mysterious "tee-do-do-eet."
Enter two enterprising Ecuadoran researchers who think they may have a solution to both problems: there might just be an app for that. Hugo Andrade and David Puente have developed a software system that "transforms sound into a sequence of numbers that can be readily converted and printed in a Quick Response (QR) barcode."
They debuted a prototype version of the software at last week's meeting of the Acoustical Society of America, where attendees were able to see firsthand how the system imports recorded sounds and transposes into a QR barcode, and then "decodes" it using a conventional barcode scanner.
The next step for Andrade and Puente is to adapt their software into an app for smart phones, a kind of mobile catalog in searchable "e-book" format. That would be the ultimate pocket field guide for birdwatchers, wouldn't it? Instead of lugging around lots of pricey and heavy equipment, enthusiasts could happily go about their birdwatching business armed with just a field guide and a mobile phone with a built in camera. If they hear a bit of birdsong, they can look it up on the smart phone app, which will contain a picture of the bird (for visual identification) and a barcode that can be played so watchers can verify the birdsong matches what they've just heard. "No more confusing tweeting sound descriptions!" Andrade declared in his lay language summary of the work.
Ideally the software could also be adapted for recording purposes in the field as well, to capture the sounds of various animal species — birds, sure, but also frogs, insects, bats, and so on. So perhaps the next time Eric Fortune goes into the field to capture the dulcet tones of his beloved plain-tailed wrens, he'll have far less baggage to lug around.
