Scientists Can Now Track How High Songbirds Fly Over the Ocean—a Potential Lifesaver

Swarmed by mosquitoes and carrying 10-foot metallic poles, biologists Erik Johnson and Olivia Butler splash by way of a swampy nature protect in Lafayette, Louisiana, on a mission. A live performance of fowl calls rings out, however the Audubon Delta scientists hear for one particularly: a transparent, high-pitched candy, candy, candy, candy—the tune of the brilliant yellow Prothonotary Warbler, or “swamp canary” as they’re nicknamed in Louisiana.

Stopping close to a nest field, Johnson stretches a internet throughout the poles whereas Butler locations a yellow rubber duck—the right coloration and measurement to behave as a decoy—close by. She then performs a wide range of warbler calls on a speaker, making an attempt to lure a fowl. For quarter-hour, flashes of yellow swoop from department to department—till lastly, one flies into the web. “Sure!” Butler whispers. “Typically it takes simply mixing it up sufficient,” Johnson says. The pair catalogue all the things—the fowl’s wingspan, the size of its legs, and even take a pattern of poop—after which affix what seems like a tiny backpack between its wings. Delicately adjusting the “straps” utilizing a crochet needle and a popsicle stick, Butler wiggles the geolocator into place. 

The tag will assist the scientists observe the warbler on its migration throughout the Gulf of Mexico to Colombia and again once more subsequent 12 months. Though Lafayette is about 25 miles from the ocean, the group hopes the info—from this fowl and plenty of others—will assist information the way forward for offshore wind growth and hold migratory birds secure throughout long-haul flights. That’s as a result of these units can do one thing that different monitoring know-how can not: measure how excessive the small land birds fly throughout lengthy stretches of water.

In terms of stopping collisions with offshore wind generators, avian flight top is a giant deal, Johnson says. In the present day’s generators could be constructed to achieve greater than 900 toes above the ocean floor. If songbirds keep properly above these heights, then collisions wouldn’t be a menace, he says: “But when they arrive decrease into the environment…that would put them in danger.” Whereas no generators function within the Gulf of Mexico in the present day, the Biden administration held the primary federal offshore wind lease public sale there in 2023 and had deliberate others. Louisiana has additionally thought-about two tasks in state waters, nearer to shore.

Lowering avian dangers posed by wind vitality tasks is a precedence for conservation advocates, says Invoice DeLuca, Audubon’s director of migration science. Although they’re not a number one explanation for fowl deaths (and fossil gas infrastructure kills far extra birds general), turbine collisions can hurt species which might be already in decline, he says. However, renewable vitality deployment is urgently wanted to scale back fossil gas use and assist stave off the worst results of local weather change, which poses existential danger to each birds and folks. In america, offshore wind tasks are a key a part of that puzzle, a 2025 Audubon report discovered.

Offshore wind farms can negatively have an effect on birds in a number of methods: displacing them from habitat, lowering meals availability within the marine ecosystem, and, most acutely, inflicting collisions. The federal authorities’s intensive vetting of wind websites earlier than leasing helps alleviate these dangers (although Louisiana’s siting course of for state tasks has, up to now, been much less environmentally rigorous). Operators may act to reduce hurt after farms are constructed—by outfitting constructions with flashing lights to discourage birds or turning off generators throughout excessive collision-risk instances,  for instance. These methods, nevertheless, require knowledge about the place and when totally different birds fly over water.

That’s the place the monitoring units are available in. Sometimes geolocator tags which might be light-weight sufficient to make use of on small species like a Prothonotary Warbler—a fowl that weighs lower than 5 pennies do—sense modifications in ambient daylight to gauge its approximate path. However they’ll’t measure its top. The brand new tags measure barometric air stress. Mixed with different knowledge, the know-how permits scientists to pinpoint each the warbler’s flight path and altitude.  

Because the venture started in 2024, Johnson and analysis companions in Louisiana, Kansas, and different breeding areas have tagged Prothonotary Warblers, Swainson’s Warblers, and Purple Martins that every one migrate throughout the Gulf. A lot of the time, he suspects, these birds fly increased than in the present day’s tallest generators would attain—however could generally drop down in the event that they hit storms. With sufficient knowledge, he hopes to foretell when songbirds usually tend to fly at decrease altitudes. “If we are able to mannequin the connection between flight top and climate patterns, then we are able to inform the operation of wind generators and inform danger mitigation measures which might be wanted,” says Johnson, who’s now an assistant professor of wildlife administration on the College of Louisiana. 

About 1,800 miles northeast of Lafayette, DeLuca can be partnering with the Vermont Heart for Ecostudies on the same venture, centered on Swainson’s Thrushes and Blackpoll Warblers. The latter species flies for 3 straight days over the Atlantic Ocean because it migrates from North America’s boreal forest to South America. Gathering extra exact details about the fowl’s journey may likewise inform vitality planning within the waters off the East Coast, particularly within the Gulf of Maine, DeLuca says. Whereas he’s studied Blackpolls for a decade, that is the primary time he’s been in a position to collect knowledge in regards to the relationship between the birds and offshore wind growth. “Up up to now, it was a little bit of a guess,” he says. 

Whether or not extra offshore wind generators can be constructed is an open query: The rapid prospects for growth in america are shaky. Though the Biden administration sought to advance this type of renewable vitality, President Trump paused federal offshore wind allowing in January upon taking workplace. This transfer alone delayed nearly 30 gigawatts of deliberate growth, says Katharine Kollins, president of the Southeastern Wind Coalition—or roughly 100 instances extra capability than is presently working. Then, this summer season, Congress repealed wind vitality tax credit, and the Inside Division rescinded wind vitality areas that had been designated as appropriate for offshore growth. A handful of tasks have additionally been canceled attributable to provide chain points and rising prices. 

Though the trade faces simple headwinds, Kollins says that it isn’t lifeless but: “This can be a $25 billion funding in U.S. manufacturing, U.S. provide chain, and U.S. vitality infrastructure. And that’s not the sort of factor you can simply surrender.”

And no matter occurs, scientists anticipate their analysis to offer worth that goes properly past vitality planning. “Migration normally is probably the most harmful time of 12 months for migratory birds,” DeLuca says. “We all know it’s once they’re pushing their our bodies to the brink. We all know they’re tremendous weak.” That knowledge they’re accumulating could provide insights into different causes of species decline, resembling lack of stopover habitat.

Again in Louisiana, Butler releases the warbler she’s tagged. Subsequent April, she’ll return to seek out it once more and obtain the info it carries. That approach, she’ll have the ability to see—extra clearly than ever—the contours of this resilient fowl’s 5,000-mile roundtrip journey.

This story ran within the Fall 2025 problem as “New Heights.” To obtain our print journal, turn into a member by making a donation today.