Cornell's Merlin Bird ID app is a very good listener.

It’s not magic, it’s Merlin

The app’s Sound ID feature is changing how we go birding—and likely growing the hobby

(published 8-11-22)

If the party involves technology, I usually arrive late. But I’m there now and having a wonderful time.

With my new friend, Merlin.

You know those smartphone apps that tell you what song is playing? Merlin is like that, only for birds. I finally added it to my phone in May.

The Cornell Lab of Ornithology introduced the Merlin Bird ID app in 2014. It’s one of several apps that can identify birds based on color, size, location, and time of year. Upload a photo or just describe the bird and Merlin will put a name on it.

The game-changer, though, came in June 2021 when Cornell added real-time sound identification capability. Overnight, Merlin became a must-have for birders.

Merlin Project Manager Drew Weber told me the app has received about two million downloads since the launch of Sound ID. Merlin has around 8.5 million downloads in total.

We should all send a thank you note to Cornell—and to birders from all over the world who share what they see and hear in the field. The “magic” behind Merlin is the application of machine learning technology to the lab’s immense dataset of bird sightings and photos submitted by birders via eBird (another Cornell invention) and audio recordings supplied to the lab’s Macaulay Library. Cornell collaborated with experts in computer vision and artificial intelligence to bring Merlin to our phones.

American Redstart by Jackie Bowman

Try the app (it’s free) and you will understand its appeal. The Sound ID feature is addictive, and rapidly changing how we bird.

I was leading a walk at Cantigny recently during which three or four birders were using Merlin. With the app in listening mode, their phones displayed a constantly updating list of birds. We used the information like clues to guide our search.

For birders with hearing loss, Merlin is a godsend. But even those blessed with perfect hearing may lack confidence in identifying birds by sound alone—a trained skill we call “ear birding.”

Some bird songs are loud and easy to learn, like those of the blue jay, cardinal, and house wren. Most birders would not need Merlin to identify them. But when a half dozen or more species are all chirping, chipping, and whistling at the same time, at various distances, at different frequencies and volumes, Merlin can sort it all out.

Sometimes a single bird might have you stumped. Never fear, Merlin to the rescue.

In June, I was hiking at Devil’s Lake State Park in Wisconsin and kept hearing some faint call notes. A bird seemed to be following me, but I couldn’t find it in the trees. Then I remembered Merlin. I pulled out my phone and activated Sound ID. Within 10 seconds the app picked up American redstart, and minutes later a dazzling black and orange male finally revealed itself.

It’s amazing how much easier it is to find a bird when you know what to look for!

Baltimore Oriole by Linda Petersen

Merlin isn’t perfect, though. The app offers “best matches” based on the input it receives. On that Cantigny walk we all heard a loud oriole-like song that sounded a bit different. Merlin told us a tufted titmouse was present—a strong candidate for Bird of the Day! After a brief chase, however, we tracked down the true singer, a Baltimore oriole.

Species with highly variable songs can fool Merlin, just like they fool humans. (No question, the birds love doing this.) But the app never stays down at our level for long. It usually nails the ID.

Birding is easier with Merlin, which makes the hobby more accessible. Cornell’s Weber said the app’s goal is to demystify identification, so that anyone can ID the birds around them. Tech-savvy young people might be drawn to it especially. Merlin adds a coolness factor to birding.

With Sound ID, birders of all ages and skill levels have a superpower at their fingertips. Those rare birders who can identify any bird by sound without a device will become rarer still—ear birding may become a lost art.

I do have mixed emotions about smart phones in the field. Birding is a chance to be off-line from technology and most of us need that. It’s also quite satisfying to find and identify an uncommon bird on your own, completely unaided.

My advice is to download Merlin and use Sound ID as much or as little as you wish. Over time you will figure out what degree of use feels right. Many birders apply it to confirm and document their IDs. Merlin records as it listens, providing an audio record for later review.

I am trying hard to use Merlin only as a back-up for ID purposes, listening with my “real ears” as much as possible. With the app constantly on, I’ll spend too much time looking down.

It’s called birdwatching for a reason. Seeing birds is still the main point.

Copyright 2022 by Jeff Reiter. All rights reserved.