This Guy Is Mapping How Warblers Migrate, Just by Listening to Them Sing

We know where Mourning Warblers spend their winters and summers. But where they go inbetween is a mystery鈥攐ne that can be solved through their songs.

Jay Pitocchelli has worn many different hats鈥攑rofessor, ornithologist, sound technician鈥攂ut he never thought he鈥檇 be an expert on Canadian accents. Twelve years ago, Pitocchelli recorded Mourning Warblers on their various breeding grounds across Southern Canada and the Northeast United States. Back in his lab at Saint Anselm College in New Hampshire, Pitocchelli noticed an unusual pattern in the sonograms he鈥檇 made: Mourning Warblers in different breeding 鈥渘eighborhoods鈥 had their own unique songs.

The species, he discovered, is a regiolect songbird, meaning each regional population has a distinct dialect. (The phenomenon is well known in some birds, such as White-crowned Sparrows and Blue Tits, but hasn鈥檛 been documented in many warblers.) One Mourning Warbler population, for instance, will sing the same song over hundreds of miles, but when there鈥檚 a barrier鈥攁 mountain range, say, or a big lake鈥攖he birds change their tune.

This finding gave Pitocchelli an idea. For years he鈥檇 been trying to chart the Mourning Warbler鈥檚 course through North America. The birds mainly winter in Costa Rica, Panama, and northwestern South America, before migrating through Mexico and into Texas. The 鈥擭ewfoundland, Nova Scotia, Prairie Provinces, and Eastern鈥攅nd up breeding in different areas of Canada. By listening to a Mourning Warbler鈥檚 song, he might be able to follow their entire migration.

In May 2015, Pitocchelli launched a . He asks birders to record Mourning Warbler songs on their phones every April through May. 鈥淲hen people send their recordings, I can immediately see in the sonogram where [in Canada] the bird鈥檚 from. It鈥檚 like I鈥檓 reading it in Spanish or French,鈥 Pitocchelli says. He then marks the bird鈥檚 location and connects the dots to trace a route.

Ultimately the project could document evidence of changes in birdsong in real time. 鈥淒oes it look like there鈥檚 the potential for a new species to evolve within this Mourning Warbler breeding range? Are they migrating together, or are they separating from other populations? That鈥檚 what we鈥檙e trying to find out,鈥 Pitocchelli says. He鈥檚 already detected that birds converging on the boundary of the Prairie and Eastern regiolects, just north of the Great Lakes, sing hybrid songs.

Having dozens of birders record sounds from the field might also prove useful for studying other elusive, scattered species. Or it could lead to the discovery of a new regiolect candidate. 鈥淚t鈥檚 a great approach that demonstrates how citizen scientists can make substantial contributions to our knowledge of bird biology,鈥 says Lauryn Benedict, an at the University of Northern Colorado. Every recording is an earpiece into an avian world, one that we鈥檙e just beginning to decipher.

Got a good ear for warbler songs? Send an email to jpitocch@anselm.edu to learn how you can help with the mapping project. You can even get in some practice with our song quiz below.

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Can You Translate These听Warbler Tunes?

See if you can guess which regiolect these birds are from, based on their sound clips (courtesy of Jay Pitocchelli). Remember, your options are: Eastern, Prairie, Newfoundland, and Nova Scotia. Answers are at the bottom.

颁濒颈肠办:听

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颁濒颈肠办:听

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1) Nova Scotia; 2) Prairie; 3) Eastern; 4) Newfoundland 听 听 听