“You’re Bob Duchesne!”
I was not expecting to be recognized as I boarded a boat in southern Florida last week, but our tour guide was Jennifer, a young lady from Plymouth, Maine.
She had spent many summers guiding kayakers out of Bar Harbor, and now helps visitors appreciate the abundant flora and fauna of Everglades National Park.
It was a fascinating boat tour. I’ve been to the Everglades many times and I’ve seen a lot of alligators, but not that many crocodiles. Until now.
I met plenty of other Mainers on this trip, most of them birds. The majority of Maine’s nesting songbirds winter in the tropics. For some, Florida is far enough.
When all our gray catbirds fly south, they crowd in with all the Florida catbirds. In March, catbirds are ridiculously abundant in the Everglades.
It’s hard to understand how Maine’s bog-loving palm warbler got its name, until you observe hundreds of them wintering under the palms.
Many songbirds start singing on their wintering grounds before heading north. The northern parula is a tiny warbler that winters on Caribbean islands. Some migrate no farther than the southern tip of Florida. We heard so many singing at Corkscrew Sanctuary near Naples that a ranger felt obliged to point them out.
This explains another new phenomenon.
I saw more people than ever using Merlin to identify bird songs. Merlin is a free downloadable app from the Cornell Lab of Ornithology. I chuckled quietly every time I saw someone listening to bird songs while staring at their smartphones.
I highly recommend Merlin. It takes a long time to learn the bird songs in your own neighborhood. It’s even more difficult to recognize songs while traveling far from your home.
Although Merlin puts the entire world of bird songs at your fingertips, it is a shortcut with shortcomings. It is uncannily accurate much of the time, but it makes mistakes.
Often Merlin’s errors are because of the birds themselves. Once you get good at recognizing birds by ear, you can also recognize how badly some birds sing. Imagine your worst night in a karaoke bar.
Merlin’s strength and weakness is that it relies on an enormous, crowd-sourced database of bird vocalizations. It searches for a sound that best matches what your smartphone microphone picks up.
By necessity, the database contains lots of good songs but also some bad. As more songs get added to the database, the app continues to get more accurate. Merlin suggests its best guess. It’s usually correct, but not always.
This creates a challenge for another free Cornell Lab product, eBird. It’s also a database app that stores bird lists online for users, and aggregates the data for scientists and researchers.
Anytime an unusual sighting is reported to eBird, experts review it for accuracy. Unfortunately, when Merlin alone is used to confirm the identity of a singing bird, eBird reviewers have no way to know whether the original identification was accurate.
I recommend using Merlin and eBird. I also recommend getting a visual verification of any unusual bird identified by Merlin before listing it on eBird. The reviewers thank you.
I rarely use Merlin when listening for Maine birds. I know just about every noise a Maine bird can make. But I used it in the Everglades several times. Many birds have regional accents, and some of the birds I heard were singing slightly different tunes than what I hear at home.
One bird near my campsite was particularly annoying. It sounded like a cross between a yellow warbler and a Wilson’s warbler. Merlin said it was a yellow warbler.
But most yellow warblers leave the mainland in winter, migrating over the Caribbean to Central and South America. Some stop on islands along the way. Only a few winter in Florida, some in the Everglades.
Most Wilson’s warblers winter in Central America, although a handful are spotted in southern Florida each winter. Yellow warblers tend to sing out in the open where they are easily seen. Wilson’s warblers tend to sing from the shadows. Not once in four days did this mystery bird ever show itself.
I never found out what it was. I certainly didn’t list it on eBird, despite what Merlin was telling me. If you’re curious and willing to buy the plane ticket, I’ll volunteer to go back down and check.
