Teaching a computer to identify bird sounds is a lot like teaching a human a new language: it takes a lot of listening. Cornell Lab of Ornithology’s Merlin Bird ID app is a free mobile app that helps birders identify birds by their songs and other sounds.
How does that work?
To correctly identify a species, staff at Cornell load at least 150 recordings of that species into Merlin’s database so it can use artificial intelligence to recognize vocal variations between individuals and populations. The team assesses performance for each species to determine how often Merlin detects the bird and how often it gets the identification correct, then adds or adjusts their training data as needed before releasing it in the app.
“When we were training Merlin to identify Carolina Wrens, we made sure to include songs and calls from across their range because wrens in Florida sound pretty different from wrens in New York,” explains Alli Smith, a Cornell project coordinator.
How does Audubon’s Corkscrew Swamp Sanctuary fit in?
Cornell staff aren’t the only people adding to this library of sounds. Smith says they have just over 3 million sound recordings of birds from about 50,000 birders around the world. A total of 5,266 of their recordings are from Collier County, Florida. Of those, 407 are from Corkscrew Swamp Sanctuary.
In late February, Smith visited the Sanctuary with recording equipment to add more sounds to the Merlin library. She recorded 67 species — 40 from the boardwalk. The lack of background noise makes the Sanctuary a great place for sound recording, says Smith. It’s also a fabulous place to make recordings of wetland birds like Anhingas and White Ibis, which normally fly away before an audio recorder can come within range.
“So far, 23 recordings from Corkscrew Swamp Sanctuary have already been used to train Merlin, not including the recordings I made during my visit. Birders are the ones truly powering Merlin,” Smith adds.
Why is this important?
Birds are our superpower. Their beauty, songs, and personalities capture the imagination of people around the world. Bringing people together to appreciate and understand birds is the first step toward inspiring actions that protect them. By adding data to Cornell’s apps, community scientists are driving that effort forward.
As of 2026, Merlin can identify most birds of the United States by sound, but Smith says there are still a few species that need more information for Merlin to identify. Corkscrew Swamp Sanctuary did not disappoint.
“I was most excited to record White Ibis because that’s a bird we don’t have enough recordings for yet to train Merlin,” says Smith. She anticipates that her recordings from the Sanctuary, combined with uploads from birders going out to record them, will be enough to add White Ibis to Merlin’s Sound ID this spring.
Once Merlin’s new update is released, birders everywhere who use Merlin will be able to identify White Ibis, partly thanks to the birds at Corkscrew Swamp Sanctuary.
For more than a century, Audubon has been working to secure and preserve the habitats birds rely on for their breeding, migration, and other essential needs. These protected habitats even serve as training grounds for better birding tools.
