Even the magical bird-identification app Merlin makes mistakes | Arts & Culture

Before the summer sun drops a ray of light over the horizon, the dawn chorus begins. It’s still dark and the thrushes and woodpeckers, the cardinals and robins are singing, their melodies punctuated by the constant clanking of green tree frogs. Some mornings, as I prepare to take my morning walk, I leave my iPhone on the windowsill open and fire up the Merlin’s Sound ID phone app.

Immediately, Merlin waves his magic staff and the app starts displaying the singing species one after another. Most of the species I have already detected through the open window. Others I need outside and closer to the singing bird. The AI ​​program is set to identify a bird’s song within 3 seconds, faster than human hearing, or at least mine, especially if five or six or more birds are competing for center stage.


Merlin, developed by the Cornell Lab of Ornithology in 2017, works in tandem with its other app, eBird, which collects and stores bird sightings from popular birdwatchers around the world. Like its namesake, the legendary wizard, the Merlin app appears to have supernatural powers, but it, like many other new AI programs, has sprites and glitches that disrupt its omniscience.

This isn’t particularly a problem for the birder who keeps a daily log of his or her sightings in the field, but people can and do report their trip lists directly to eBird, which uses this data to track bird populations during migration and throughout the year. Ultimately, the information can be used to create conservation regulations and other protections for birds.

There are 118 species of kingfishers in the world. Only one lives in the Berkshires.

(For those who want instant, absolute identification, there are now binoculars available for about $7,000 that will do just that: the Swarovski Optic dG. Seriously! What’s the point? There goes all the wonder and fun of walking in the woods, seeing the daily, monthly, and seasonal changes of the natural world. Just leave your brain on the windowsill and let the AI ​​do all the work.)

When I first started using Merlin, I was amazed at how well the app works. If Merlin tells me that among the noisy morning chorus it detects a little blue-grey pearl that I don’t hear at first, over time I can locate and observe it.

When I hear a bird call I don’t recognize and Merlin gives me a common bird for identification, I can listen to it on the Sibley app. I go through the many examples of this bird. Please note: When you do this (open the Sibley app and listen to the call), Merlin goes deaf. You will have to go back and save the identification information for the most recent sound or you will disappear into cyberspace, never to be seen or heard from again.

But you will learn. Toquíes, for example, have many different songs that I have now learned to recognize. Carolina wrens, too. The app also gives me the ability to refresh my memory of bird songs, especially the warblers that I hear only when they pass through during spring migration: Chestnut-breasted Warblers, Nashville Warblers, Mourning Warblers, and Wilson’s Warblers.

To see Wilson's warbler in the Berkshires, you need to be in the right place at the right time.

One day, as I was passing the large pond down the street, Merlin reported the presence of a Eurasian Pygmy Owl, the smallest owl (15–18 cm) in Europe and all of Asia as far as China and northern Japan. Hmmm, a Pygmy Owl, how odd. My first thought when Merlin heard a bird from another continent was that it was an escaped bird… from a zoo or an owl collector. But often these foreign birds are only recorded once and there is no bird call for me to track. This is definitely a software glitch. Go to eBird World on the web to listen to any of the reported foreign birds.


Last week, Merlin recorded four different foreign birds: the Slate-colored Solitaire, a resident of Mexico and Central America; the Green-winged Manakin, from the Argentina/Bolivia area in South America; the Chivi Vireo, from all of South America; and the Yellow-green Vireo, also from Mexico and Central America. Merlin had detected the Yellow-green Vireo on my trail in two previous years. Again, none of these birds sing more than once.

And just a couple of days ago, the app detected a cup-winged pygmy woodpecker, native to Southeast Asia. Interestingly, this species also showed up for me when Merlin heard it in Portal, Arizona, in April. The cup-winged woodpecker is not a genus I’m familiar with at all. It’s a small, brown, scaly-breasted, egg-shaped bird (with virtually no tail) found on the forest floor of the Himalayas and other parts of Southeast Asia.

The wings are not cup-shaped, but this bird could fit in a teacup.

I listened to the songs of these birds and tried to determine what Merlin was confusing them with. The only one I see any similarity with is the Pygmy Woodpecker. The Pygmy Woodpecker’s song sounds similar (somewhat) to some of the song of our Woodpecker. This year, many, many Woodpeckers are calling constantly from dawn to dusk from the nearby woods.

I never report these sightings to eBird. Others do and the staff asks for more information about the sighting and I would definitely prefer a photo. I haven’t used the photo portion of Merlin, but I know that when using the Seek app for bird identification, you have to be pretty close for it to make any sort of valid identification. Such a rarity, a Pygmy Fluttershrike, would bring a lot of birders laden with binoculars, spotting scopes and cameras with giant lenses my way.


Merlin is very consistent. The app has reported the presence of a Wood Warbler at the edge of my property many times this spring… possible, but not likely. Because the bird sings over and over, I can find it among the roadside honeysuckle. Every time I do this, I end up seeing a Song Sparrow open its beak and sing. Then I look at the screen and the app records a Wood Warbler again. The songs are similar, but they have quite different pitches to their trills. I wish I could add the Wood Warbler to my lists of houses and roads!

Bird nests can be found virtually anywhere in June.

Often Merlin records a brown mockingbird on the trail, a bird I am quite familiar with. It is not an uncommon bird that I see and hear from time to time when I am out birding. But when a mockingbird finds a nice perch and begins to sing, it usually continues exuberantly for more than a few minutes repeating each phrase twice. So when Merlin reports a mockingbird, I look around, because they are beautiful birds. Nothing. Then I see that, within the next entries presented by Merlin, is a grey cat. The cat, also a mimic, does not know enough to repeat each individual phrase twice. Another constant mistake by the wizard.


Reporting native birds like these two to eBird will skew population and range data for the species. The Thrasher is not a problem, but if eBird is told that many of the Chipping Sparrows here in the Northeast are Worm-Eating Warblers, it would seem like there is a population explosion of this warbler that never wants to get up close and personal.

The Philadelphia vireo, which sounds very similar to the red-eyed vireo, is often misreported to eBird via Merlin, so new maps created from this information can provide false data about population growth and range expansion. For this reason, eBird will field requests for more details and photos of birds like the Philadelphia vireo and the Worm-eating warbler before publishing valid sightings.

Merlin includes indicators, small red dots or half-dots next to the bird’s name for uncommon birds heard in an area where it might be out of territory or out of season, but I find these not particularly accurate. The Brown Nuthatch invariably shows up on my screen with a half red dot even though they are here all year round and have nested here year after year. There are probably two or three breeding pairs along the way.

Another strange flaw… sometimes when I see a bird singing less than five feet away, Merlin doesn’t record it at all. I’ll move a little bit back and forth or hold the phone up and point it at the bird and… nothing. It’s like Merlin is taking a nap or totally distracted by other sounds.

Even though Merlin may be wrong at times, the app is magical and a wonderful learning tool!