Butterfly Mystery Solved

摘要

Monarchs aren't the only continent-hopping butterflies. A new study finds that painted ladies (Vanessa cardui), common in Europe and the United Kingdom, are also long-distance commuters, traveling back and forth to North Africa. Although the insect's northward trip to Britain has been well-documented by citizen scientists, few saw them heading south again across the English Channel-suggesting the commute might be one-way. But in the spring of 2009, millions of painted ladies hit the shores of the United Kingdom, enabling researchers to correlate some 60,000 sightings with data from radars monitoring insect movements above 150 meters.