A boreal songbird's 20,000 km migration across North America and the Atlantic Ocean

The 12- g migratory blackpoll warbler has one of the most spectacular migrations in the world. We used miniaturized devices to track the movements of blackpolls breeding at four northern locations, including as far west as Nome, Alaska, USA. In fall, all birds crossed North America to stop over on the Atlantic coast and then made a 3- day, nonstop flight over the Atlantic Ocean to South America, eventually reaching the Amazon Basin. For some birds, this round trip was over 20,000 km. These critical connections provide important information for understanding the causes of decline in one of North America’s fastest declining songbirds.