Backpack-toting birds help researchers reveal migratory divide, conservation hotspots

"Birds of a feather do not necessarily flock together," says Kira Delmore, a PhD student with UBC's Department of Zoology and lead author of the paper. 

Pictue: Wikipedia

"Our teams of thrushes took dramatically different routes to get to their wintering grounds, either south along the west coast to Central America, or southeast to Alabama and across the Gulf of Mexico to Columbia." 

The study, to be published this week in the Proceedings of the Royal Society of London B, is the first to collect a complete year's worth of data from individual birds to document such a migratory divide. 

"This detailed level of migration and stopover data helps us pinpoint vital feeding and rest habitats that the birds rely on at key points during their long journey – just before crossing the Gulf of Mexico, for example," Delmore adds. 

The researchers say the study also raises the possibility that migratory behavior may play a role in speciation, the process by which one species evolves into two. 

"Given that migratory behavior is under genetic influence in many species of birds, these results raise the question of what hybrids between these two subspecies would do," says Darren Irwin, associate professor of Zoology at UBC and co-author of the paper. 

"One possibility is that hybrids would take an intermediate route, leading to more difficulties during migration. If so, the migratory differences might be preventing the two forms from blending into one."

Read more at: http://phys.org/news/2012-09-backpack-toting-birds-reveal-migratory-hotspots.html#jCp

More information on Swainson's thrush (Catharus ustulatus):

http://www.allaboutbirds.org/guide/swainsons_thrush/id

http://www.birdweb.org/birdweb/bird/swainsons_thrush