Tiny radio transmitters provide insect migration clues

Wind and warmth can improve travel time for the billions of insects worldwide that migrate each year, according to a first-ever radio-tracking study by University of Guelph biologists.

Researchers equipped monarch butterflies and green darner dragonflies with radio transmitters and tracked them through southern Ontario and several northern states.

They wanted to learn how environmental factors affect daytime insect migration, with the goal of informing conservation efforts.

“Migration is not an easy period for insects. They are likely pushed to their physiological limits,” says integrative biology professor Ryan Norris, who conducted the study with lead author Samantha Knight.

“If we have a way to track and understand what habitats they’re using, that goes a long way to understanding what might be causing declines.”

The study, recently published in Biology Letters, found wind and temperature are more important influences than precipitation for bugs during long autumn migration flights. On average, monarchs flew about 12 kilometres per hour and darners about 16 kilometres per hour.