Merlin reminds us that technology, when used well, can deepen our relationship with the living world.
Peterborough Examiner – November 7, 2025 – by Drew Monkman
Bird activity was pretty slow on a recent October morning at Silent Lake Provincial Park. All I could hear were the occasional chip notes of yellow-rumped warblers. Suspecting that my less-than-perfect hearing was missing some birds, I opened the Merlin Bird ID app, tapped Sound ID, and held up my phone. Almost instantly, other species began to appear: White-throated sparrow, golden-crowned kinglet, brown creeper. Then, to my surprise—scarlet tanager! I cupped my ears and listened hard. Sure enough, there it was—the sharp chik-brr notes I might never have noticed without Merlin’s help. Just to be sure, I confirmed the sighting with my binoculars.
Moments like this feel like magic. But they’re also the result of some of the most sophisticated wildlife technology ever made available to ordinary nature enthusiasts. In less than a decade, the free Merlin Bird ID app, developed by the Cornell Lab of Ornithology, has transformed how people identify birds — and, more importantly, how they connect with nature. It’s hard to overstate the influence of Cornell’s Merlin app to the growth of birding.
“It’s been so inspiring to see how many young people are getting into birds through learning about Merlin on social media and how celebrities like Sarah Jessica Parker are even posting about it,” said Ali Smith of the Cornell Lab and a recent guest on the American Birding Podcast from the American Birding Association.
A new kind of bird guide
When Cornell launched Merlin in 2014, its goal was simple: make bird identification easier for everyone. Field guides remain beloved and essential, but they’re static—they can’t tell you what’s singing in your yard today. Merlin, by contrast, is dynamic and personalized, now covering over 10,000 species worldwide. It’s powered by a vast global database of photos, recordings, and sightings contributed through eBird – Cornell’s bird checklist and citizen science platform- meaning every verified observation helps make Merlin a little smarter.
Step by step ID
Merlin’s Step-by-Step ID feature guides you through identifying a bird using a few simple observations—no photo or recording needed. You start by entering where and when you saw the bird, which helps narrow the list to species likely in that area and season. Then you describe its size, main colors, and what it was doing (perched, soaring, swimming, etc.). Based on millions of eBird sightings and expert data, Merlin instantly suggests the most probable matches, each with photos and sounds for comparison
Download the app and try the step by step feature with a bird you already know well like a black-capped chickadee. Does Merlin get it right?
Photo ID: Machine learning
One of Merlin’s most impressive features is Photo ID. What feels like wizardry is actually machine learning — the same kind of artificial intelligence that allows facial recognition software to identify people.
Snap a picture of a bird – preferably with a camera with a zoom lens but maybe even with your phone if the bird is close – upload it to the app, and within seconds Merlin offers a ranked list of likely species. I sometimes use my phone to take a picture of the image displayed on my zoom camera’s screen, and then import that photo from my phone into the Merlin app. Even with blurry or backlit images, Merlin often nails the ID.
Try it at home by taking a picture of a bird with your phone – maybe from a bird book or website – and then use the picture in Photo ID. Is Merlin right?
Sound ID: Hearing the invisible
If Photo ID is clever, Sound ID is jaw-dropping. We hear far more birds than we ever see, and Merlin helps bridge that gap. People suddenly become aware of all the incredible birds singing right in their neighborhoods – species they might never have noticed before. When Sound ID was introduced, the number of people downloading Merlin exploded. It now stands at over 23 million.
Released in 2021, the sound feature converts sound into a spectrogram — a visual map of frequency and time — and compares it to thousands of known bird songs. When you see Merlin detect a half-dozen species at once — many of which you hadn’t consciously heard — you realize just how much is happening in the soundscape around you.
To see how Sound ID works at home, go to YouTube and search
“1 Hour of North American Bird Songs and Calls”. Turn on Sound ID, play the video and watch the wizardry happening on your phone’s screen. You’ll now be ready to enjoy the app in your own backyard.
A living, local birding tool
Beyond identification, Merlin functions as a portable, custom-built field guide. The “Explore Birds” section lets you browse species known from your area, complete with multiple photos, range maps, vocalizations, and concise ID tips. Because it’s powered by eBird, the app tailors results to what’s actually present near you, at this time of year.
You can even download regional bird packs for offline use — perfect for travel or remote areas with poor cell service. I used the Colombia pack a year ago and was amazed that even in remote cloud forests, Merlin could recognize many of the more common species by sound alone. In places like Latin America, however, there are still many bird vocalizations the app has yet to learn.
Outshining field guides
Traditional field guides are still invaluable for quick visual reference without having to navigate through the app, but Merlin has three big advantages. First, it’s personalized—showing only the birds likely in your area at that time. Second, it removes barriers for beginners, guiding users without requiring prior knowledge of field marks or bird families. By reducing frustration, it’s introducing birding to countless new people — especially younger generations raised on smartphones. And third, it’s alive – constantly updated with new data and species, making it the first field guide that truly learns.
The technology under the hood
What powers all this? In simple terms: machine learning and big data. Merlin’s models are trained on millions of real-world observations. Neural networks learn to distinguish subtle features in photos or sound patterns just as humans do, but with far greater speed and scale. To teach Merlin to identify just one bird by sound, a minimum of 150 different sound recordings of that species are required.
When you open the app, it uses your GPS location, date, and recent eBird data to narrow down the field. It’s weighing probabilities based on season, region, and habitat.
Each new eBird checklist, each uploaded photo or uploaded recording, improves Merlin’s accuracy. In a very real sense, birders everywhere are teaching the app to see and hear more clearly.
Transformative, but there’s caveats
Merlin amplifies curiosity. It gets you listening harder, watching more closely, and noticing details you once overlooked. Beginners who start with Merlin often move on to binoculars, purchasing field guides, and using the eBird app to submit checklists, photos and maybe even sound recordings. The Merlin app is a doorway to much more.
Merlin is amazing, but it’s not perfect—mistakes happen, albeit rarely. Its identifications can sometimes be off, especially in noisy environments, when birds overlap in song. For example, I’ve noticed that Merlin will sometimes confuse northern cardinal for a tufted titmouse. Usually, however, the misidentified bird will only come up once in the list on the screen. Birds that are properly identified come up (flash yellow) numerous times.
For serious birders, Merlin should be seen as a powerful supplement—not a replacement—for binoculars, field guides, and your own experience in the field. If Merlin says it’s a certain species, great—but take a moment to double-check the call, the habitat, the time of year and what your own eyes and ears are telling you.
Merlin reminds us that technology, when used well, can deepen our relationship with the living world. It brings us closer to the birds themselves — and to the joy of simply knowing them better.
