Monarch Butterfly

New research suggests that the circadian clock that helps migrating monarch butterflies (Danaus plexippus) navigate based on the changing position of the sun is in their antennae -- not their brains -- as was previously thought.



Researchers surgically removed the antennae from some of the monarchs, then tethered and flew the butterflies outside in a flight simulator. The butterflies lost their normal southwestern orientation, even though the clock molecules in their brains were keeping normal time. The exact nature of the connection between the clocks in the antennae and brain is still unclear.