Where are flying butterflies headed? Just looking for some food and a comfortable and safe place to rest. And they also know where to find it.
|Where will this butterfly go? Inachis io is common in Asia and Europe and has a wingspan of 55 millimeters.|
Controlled flight. On the back of the butterflies - belonging to two different species, the Inachis io and the Aglais urticale - very small antennas have been attacked (weighing 12 milligrams). Subsequently the insects were released in a field controlled by a radar that recorded all their movements. "For the first time we were able to follow them in flight for more than a kilometer - says Lizzie Cant of Rotundsted Research in Harpenden - and it seemed to us that they follow a precise direction".
Orientation in the wings. When they have to move from one place to another, the butterflies fly in a straight line at a fairly sustained speed of 2.9 meters per second. If, on the other hand, they are looking for food or a comfortable "bed" to rest, they fly more slowly (1.6 meters per second) in a spiral movement. From the observations made it seems that to guide a butterfly, during the "spiral flight" phase, is an extraordinary sense of orientation, capable of making it identify a flower or a tree suitable for its purposes, even 200 meters away.
The study of butterfly navigation provides important indications on their path, on speed but also on feeding behavior. All valuable information for their preservation.
(News updated April 8, 2005)