To find clues to insect migration, scientists in Germany took their research into the sky, attaching tiny trackers to the backs of giant moths and following them with a plane.
To the researchers’ surprise, the moths had a great sense of direction. In a study published Thursday in the journal Science, scientists reported that even when the winds changed, the insects followed a straight path.
Their flight paths indicate that these death sphinx moths have somewhat complex navigation skills, with the authors challenging previous ideas that the insects simply move around.
“For many, many years, it was thought that insect migration was primarily determined by winds, and that they moved around driven by wind,” said study lead author Miles Mainz, who is now in Australia. James is a zoologist at Cook University. ,
Mainz explained that scientists have found it difficult to closely observe how insects travel, due to their small size. The types of radio frequency tags used to track birds can be too heavy for small fliers.
But transmitters are getting smaller and smaller. And it helps that the death sphinx moth is huge compared to other insects, with a wingspan of up to 5 inches (12.7 cm).
This iconic species – with dark, yellow underwings and skull-shaped markings – was able to fly well with a small tracker attached to its back, said study co-author Martin Wikelski and a researcher on migration. Max Planck Institute for Animal Behavior in Germany.
The moths are believed to travel thousands of kilometers between Europe and Africa in the fall, flying at night.
For the study, the researchers released the tagged moths in Germany in the hope that they would begin flying on their migration route to the Alps.
Wikelski, the pilot of the study, took off in his plane, flew over the area and waited for the kites to take off. If it picks up a signal from a small passenger, it follows its radio signals, for hours at a time.
“The little insect is guiding you,” he said.
The researchers followed the flight paths of 14 moths, whose longest runs were about 90 kilometers (56 miles).
The moths not only flew in a straight line, but also seemed to deal well with wind conditions, Mainz said, when they encountered a headwind, or land to take advantage of the tailwind to push them along. But they were flying low.