Each fall billions of songbirds leave North America on an epic journey to their faraway wintering grounds in Central and South America where many live in tropical forests shared by toucans, howler monkeys, and jaguars. Dozens of these migratory bird species have experienced serious, long-term population declines that are driven in part by the threats they face on migration and while in the tropics. But only recently has it been possible, using geolocators, to track the entire migration of individual songbirds to find out how they accomplish their amazing round-trips and to map the critical habitats they use during migration and while on their wintering grounds. Bridget Stutchbury, who teaches at York University in Toronto, has been tracking and studying since the 1980s the migration of Purple Martins and Wood Thrushes, both declining species.
