1st October 2019
Purple martins will soon begin their yearly winter migration but this time they’ve got a new accessory. The birds will be wearing little backpacks that will track their roosting sites.
As the bird travels north from Brazil, the purple martin roosts in small forested patches on their rout to North America.
“This is highly unusual behavior for songbirds, which typically roost in heavily forested areas,” said Auriel Fournier, a co-author of the study with University of Manitoba biological sciences professor Kevin Fraser, who led the research. Fournier is the director of the Forbes Biological Station at the Illinois Natural History Survey.
“It’s surprising to see them roosting in these forest islands, which are small, isolated clusters of trees typically surrounded by agriculture, water or recently cut forest,” Fournier said.
The research is intended to determine whether the birds are responding to a change in the environment or whether their roosting behaviour has always been this way.
“We believe they must be intentionally seeking out the forest islands,” Fournier said. “Because these habitats don’t occur very frequently on the landscape, the birds’ use of them is unlikely to be by chance.”
“We are curious if birds are choosing these isolated patches of habitat because they have fewer predators than in larger patches of forest,” Fraser said.