Monarch Butterfly migration study tracks generations
Everyone knows all about the epic breeding journey taken each year by generations of monarch butterflies between Mexico and Canada, right? Not so fast, say researchers including University of Guelph biologists.
Until now, linking adult butterflies and their birthplaces during a complicated annual migration spanning all of eastern North America and involving up to five generations of the iconic insects had eluded scientists.
Now for the first time, researchers have mapped that migration pattern across the continent over an entire breeding season. That information might help conserve a creature increasingly threatened by loss of habitat and food sources, says Tyler Flockhart, a PhD student in U of G's Department of Integrative Biology.
"This tells us where individuals go and where they're coming from," he said.
Flockhart is lead author of a paper published [online Aug. 7: embargo] in the Proceedings of the Royal Society B with Prof. Ryan Norris and co-authors based in Saskatchewan, Colorado and Australia.
Their new study traced successive generations of adult monarchs to their birthplaces between the southern United States and Ontario over a single breeding season.
Before this, scientists had only a rough idea of those annual colonization patterns, said Prof. Ryan Norris, Integrative Biology. "You could have a monarch showing up in Ontario, but we didn't know exactly where it came from."
Tracking migration patterns is vital to understanding why monarch numbers are declining and predicting the effects on the insects of milkweed plant loss, habitat destruction and other factors, he said.
In 2012, the smallest-ever population of monarchs was recorded in their Mexican overwintering grounds. "They've been declining steadily," said Flockhart.
Monarch butterfly photo via Shutterstock.
Read more at EurekAlert.