Songbirds Found to Migrate Hundreds of Miles a Day

Female purple martin sporting a tiny geolocator backpack, designed to not be obscured by feathers during flight. ID bands can also be seen on its legs.

Biologists have been able for the first time to track individual songbirds from their North American breeding grounds to where they spend the winter in Latin America, and back.

And what they discovered by analyzing data from tiny light sensors attached to the backs of some of the birds “flabbergasted” the researchers.

"The flight times were amazing," said Bridget Stutchbury, a biologist at York University in Toronto, who led the study.

"We had a purple martin that over-wintered near the Amazon River in Brazil, and it flew back to its breeding colony in the northern U.S. in only 13 days. This is incredible. I had no idea that songbirds could go this fast."

Stutchbury said the ability of some migrating birds to fly more than 300 miles (nearly 500 km) per day was totally unexpected.

Satellite tracking sensors are far too heavy to be attached to individual birds. So the researchers strapped tiny backpacks that record sunrise and sunset times, which provide a rough estimation of where the birds were on a given date.

Many more birds will be tagged with the devices now that the technology has been proven. “Tracking birds to their wintering areas is also essential for predicting the impact of tropical habitat loss and climate change,” Stutchbury said.

Pete Marra at the Smithsonian Migratory Bird Center at the National Zoo told National Public Radio that there is “still a lot of work to be done to try to miniaturize this tool even a bit more and put some other gizmos on, such as ones that would allow us to record temperature or altitude or relative humidity.”

Photo: Timothy J. Morton