Magazine article Science News

Night Flights: Migrating Moths May Use a Nighttime Compass

Magazine article Science News

Night Flights: Migrating Moths May Use a Nighttime Compass

Article excerpt

It was a dark and windy night, but millions of moths migrating over Britain could still tell which way they were going.

Radar showed that silver Y moths heading south for winter selected winds sweeping them in the right general direction, says Jason Chapman of Rothamsted Research in Harpenden, England. Moths even seemed to adjust their flight direction to compensate for somewhat off-course winds, he and his colleagues report in the April 8 Current Biology.

"This is the first good evidence for some kind of compass in nocturnal migrating insects in the wild," Chapman says.

A Rothamsted engineer custom built radar systems to study insects flying between 150 and 1,200 meters overhead. The radar systems don't scan around like conventional ship radar but instead look straight up while moving slightly. The arrangement reveals extra details, explains Ian P. Woiwod, also of Rothamsted. This radar detects the rough size and height of an insect winging overhead plus the orientation of its long body axis.

Two of Rothamsted's radar systems run continuously, and from 2000 to 2003 they recorded 42 bursts of Autographa gamma, or silver Y, migration. The researchers didn't identify the species just from radar but used other methods, such as traps attached to balloons in the region.

In fall the moths fly south-southwest toward the Mediterranean. The year 2003 was a boom year for silver Ys, and some 200 million migrated across England. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.