The blackpoll warbler weighs just 12 grams, or around two U.S. quarters. That tiny little ‘backpack’ strapped to them? It weighs just 0.5 grams. Geolocators on the ‘backpacks’ tracked the birds as they made their migration to wintering grounds in South America.
But, the devices were so small they were not able to transmit the data remotely. Instead, researchers went on a hike through the woods to find the birds they tagged once they returned from their migration.
“This is the first study to provide direct evidence of the birds’ migration route – we found they flew directly over the Atlantic Ocean to reach their wintering grounds in South America,” said Ryan Norris, who led the Canadian portion of the research.
William DeLuca, a research fellow at U Massachusetts and leader of the Vermont portion of the research, on how the blackpoll warblers prepare for their long journey. “These birds have a tremendous voyage ahead of them, with some likely flying from western Canada to the east coast before flying south. They eat as much as possible, in some cases doubling their body mass in fat so they can fly without needing food or water.”
DeLuca on the distances traveled by the birds. “When we accessed the locators, we saw the blackpolls’ journey was indeed directly over the Atlantic. The distances traveled ranged from 2,270 to 2,770 km.”
Blackpoll warblers feast primarily on insects. They enjoy a good meal of termites, ants, gnats and mosquitoes. Anything that eats mosquitoes is a fan of mine.
At the start of their migration flight, the birds can weigh more than 20 grams. During the flight, they lose at least 4 grams.