Monarch butterflies navigate using a light-dependent magnetic compass.
Patrick Guerra from University of Massachusetts Medical School and colleagues examined the butterflies’ behaviour inside a flight simulator with an artificial magnetic field.
Butterflies reversed their flying direction when the inclination angle of the magnetic field was reversed, and flew in circles if deprived of light within the 380nm to 420nm spectral range.
This helps explain how the butterflies migrate annually from their United States breeding grounds to their overwintering sites in central Mexico.
Read more at University of Massachusetts Medical School