A tiny bird and a marathon migration
A tiny songbird that summers in the forests of northern North America has been tracked on a 1,700-mile journey. It was tracked from the northeastern United States and eastern Canada to the Caribbean. It is part of the songbirds' winter migration to South America, according to a study.
Scientists had long suspected that the blackpoll warbler had made its journey to the Caribbean over the ocean. This study began in the summer of 2013. For the first time, scientists attached tracking devices to the birds. It was the first time that the flight has been proven. That is according to results published in the United Kingdom in the journal Biology Letters.
Chris Rimmer of the Vermont Center for Ecostudies is one of the authors. He called the flight "a spectacular, astounding feat." The bird weighs only half an ounce. Rimmer was amazed that the little bird could make such a perilous, highly risky journey. Especially over the open ocean.
The warblers are known to bulk up by eating insects. They fill up near their coastal departure points before heading south. The birds are common in parts of North America. However, their numbers have been declining.
"Now maybe that will help us focus attention on what could be driving these declines," Rimmer said.
Scientists hope to use the information about how the blackpoll warblers migrate. It may tell researchers more about the changing climate. That is according to Andrew Farnsworth. He is a research associate at the Cornell Lab of Ornithology. He specializes in migration biology. He was not involved in the study.
"What happens if birds aren't able to fuel sufficiently to make this kind of flight?" Farnsworth said. This could be because of their habitat shrinking in New England or the Canadian Maritimes. He continued, "How much energy do they need and if they don't get it, what happens?"
A number of bird species fly long distances over water. But the warbler is different. That's because it's a forest dweller. Most other birds that winter in South America fly through Mexico and Central America.
In the summer of 2013, scientists tagged 19 blackpolls on Vermont's Mount Mansfield. They tagged 18 more in two locations in Nova Scotia. Of those, three were recaptured in Vermont with the tracking device attached. Two were recaptured in Nova Scotia.
Four warblers, including two tagged in Vermont, departed between Sept. 25 and Oct. 21. They flew directly to the islands of Hispaniola or Puerto Rico. Their flights took from 49 to 73 hours. A fifth bird departed Cape Hatteras, North Carolina. It flew nearly 1,000 miles. It landed in Turks and Caicos. Then it continued on to South America.
On their return journeys north, the birds flew along the coast.
Critical thinking challenge: Why do the warblers bulk up before heading south?