Complex factors determine when migrating songbirds make their journeys
Date: November 2, 2015
Source: National Science Foundation
Every year, backyard songbirds across the United States make an arduous journey to warmer winter climes. They migrate hundreds of miles, occasionally braving tough terrain and nasty weather. Sometimes, they have no place to stop and refuel along the way.
Birds actually weigh these risks using a combination of factors--fat, weather and date--to make a migration risk assessment, according to new research funded by the National Science Foundation (NSF). The findings can serve as the basis for building better conservation strategies, researchers say.
The work focused on three species of songbirds, red-eyed vireos, Swainson's thrushes and wood thrushes, as they crossed the Gulf of Mexico, from coastal Alabama to the Yucatan Peninsula. The researchers published their findings in the Proceedings of the National Academy of Sciences (PNAS).
"There are a lot of studies looking at bird's departure behavior or arrival behavior," said Jill Deppe, a biologist at Eastern Illinois University and principal investigator on the NSF award. "This is the first time we've been able to take a subset of birds and gather data on both."