February 26, 2018, University of Toledo
The annual long-distance migration of rare, tiny songbirds that reproduce in the Great Lakes region and Appalachian Mountains is no longer a mystery.
By tracking one of the smallest species ever monitored over thousands of miles using cutting-edge technology, a team of ornithologists led by scientists at The University of Toledo found that it is where golden-winged warblers spend the winter in the tropics that determines if a population is declining or stable, not factors associated with the breeding grounds thousands of miles north in the United States and Canada.
Over the course of the five-year study, the scientists found that different populations of the birds, which are about the size of a ping-pong ball and weigh less than three pennies, do not mix between their separate northern nesting grounds occupied during the spring and summer and the tropical sites where they spend the winter.
Mapped using data from 76 light level geolocators recovered from the birds, each population shows strong migratory connectivity, or geographic segregation, that confirms that populations of the birds stay together in different locations for the seasons throughout the year. This strong link between breeding and non-breeding areas means that populations may be exposed to different threats and conditions during the winter.
Read more at: