What’s in a Song?

On a sunny September afternoon, the birds are just a little quiet. They flit overhead and sometimes chitter angrily at Sherwood Snyder, product manager at Wildlife Acoustics, as he hikes a loop out of the Randall Davey Audubon Center, binoculars at the ready. He's trying to get a visual on them, but mostly we're trying to get a microphone to them.

Wildlife Acoustics launched an app in February that records bird songs and identifies them. So we also hold phones at the ready with the app, Song Sleuth, poised to record.

Mostly, our results come back as rock pigeons and humans, which, yes, are in the app as well. Snyder whistles to demonstrate its ability to bust mimickers, and up pops an image of a binocular-sporting human and sample recordings of Snyder welcoming users to the app. It does not include listings for catbirds and mockingbirds, which can mirror the birds they copy so well as to fool the app itself. Nature wins again.

Birds sing to establish a territory and attract a mate, he says—the stuff of springtime. By this time of year, they're all fairly well focused on making their way to Mexico. Still, we weren't even out of the parking lot when he was identifying black-capped chickadees, and he's soon able to capture a robin song. The app comes back with three suggestions, robin the most likely of them, and two backups just in case.

"If I just record that robin and I didn't know anything, the goal is that it passes the baton off—it's one of these three—good luck,"Snyder says.

The app, which downloads for $9.99, includes illustrations from renowned birder David Allen Sibley, range maps, likelihood of spotting, descriptions and recordings from across the country to help with identifications. He plays through audio samples, and then the robin recording has the ring of a match.

Snyder zooms in on a spectrogram of the recording, which shows a jag of red against green and yellow chartings of the background noise, and uses that to isolate the sound for another listen and to compare it to the spectrogram of the audio sample.

"It makes it visual—you're basically memorizing patterns and calligraphy," he says. "It gives your brain another chance."

To train the app to recognize bird songs, Snyder reviewed more than a quarter of a million song samples from the Cornell Laboratory of Ornithology and a lab from Ohio State University. He tossed out the mislabeled samples or those interrupted by other sounds. At some point, he began doing this by sight, using the spectrograms. Visually filtering them was faster.

"Then I started seeing spectrograms everywhere—in hardwood floors," he says. It was a part insanity and part transcendence. He could see, for example, that some bird sons come in patterns like Bach, with sections to a songs that repeated in various orders.

Like humans, most birds learn dialects from their parents, making for regional variation in their songs. So the app is still growing and changing as people test it and send in their corrections. They've added more than 20,000 new recordings that way.

September may not be bursting with bird songs, but one of New Mexico's most iconic bird-watching seasons is approaching in November, when the Bosque del Apache fills with thousands of sandhill cranes, Ross' geese and snow geese wintering-over. Sandhill cranes aren't in the app—if you're looking at a big white crane with a red stripe down its face, Snyder says, you probably don't need help recognizing it.

But it's the other portion of Wildlife Acoustics' work that has brought Snyder to town—there's a conference on bats in Albuquerque. The company has also developed an app for identifying species of bats, Echo Meter Touch, based on their echolocation calls. The bat apps and equipment, which can be set up like trail cameras triggered by sound, often go to biologists surveying potential wind farm sites. Those blades can wipe out a lot of bats, and if endangered species are found living in the area, it can mean relocating.

So we take the phones back out in the evening, hiking toward a water source likely to attract bugs and therefore bats. The ultrasonic modules pick up noise we can't hear, the rattle of our clothing, the steady static of air moving. The apps crackle.

The wind picks up and the temperature drops, and the bats, wisely, stay tucked away somewhere warm while we shiver. The breeze rattles the cattails, and it's from amid some of them that real magic appears—a redwing blackbird sings strong and clearly enough the Song Sleuth app can capture it. Press a button, and the phone sings back.

The Enthusiast is a twice-monthly column dedicated to the people in and stories from our outdoor sports community.