Experiment Suspending Fruit Flies in a Magnetic Field Shows They Navigate Using Sunlight
Posted on January 27, 2012
Scientists studied fruit flies in a magnetic field to determine how the tiny insects use the polarization pattern of natural skylight to keep their bearings during flight. Scientists attached fruit flies to a metal pin with a light-cured glue and then placed the pin in a magentic field. The suspended fruit flies were tracked using digital cameras. The researchers found that flies turned when the angle of naturally polarized light was rotated.
During the hour before and the hour after sunset, the headings of flies relative to the position of the arena were recorded for 12 minutes. The arena was rotated 90 degrees every three minutes, and when natural light was not altered by optical filters some of the flies compensated for the rotations and maintained a consistent heading.Here is a video of the fruit fly executing a "body saccade" or a quick turn in the experiment:When the arena was covered with a circularly polarizing filter, eliminating natural linear polarization light patterns, the flies did not shift their heading significantly in response to arena rotations.
The research was published here in Cell Press's Current Biology journal.