The blackpoll warbler is renowned for its amazing migratory flight. Each fall, northeastern birds fly about 2,170 miles (3,500 km) from the northeastern United States over the Atlantic Ocean to their wintering grounds in Puerto Rico and South America. For most birds making the trip, this migration can involve a non-stop flight of up to 88 hours. Birds flying from Alaska, through Florida and the Caribbean, to Brazil are estimated to cover nearly 5,000 miles (8,000 km)!
To accomplish this feat, the birds leave their summering grounds after the seasonal northwesterly winds arrive in October. These winds help push the birds toward the tropics. Once in the vicinity of Bermuda, northeasterly trade winds steer the birds southward.
Studies of the blackpoll warbler show that it has an extraordinary ability to build up and store fat, nearly doubling its body mass for the trip. This is thought to be an evolutionary adaptation that exists for the sole purpose of enabling these birds to make such an unbelievable voyage.