Monarch butterflies are an amazing set of creatures. Why they need, (and how they manage), to migrate thousands of miles in their life cycle amazes me. But I can imagine that as the eons went by, optimum foods and temperatures gradually shifted locations. They just adapted to it by these amazing journeys and group memories!
Here are some hints!
"Recent studies of the iconic fall migration of monarch butterflies have illuminated the mechanisms behind their southward navigation while using a time-compensated sun compass."
- Skylight cues, such as the sun itself and polarized light, are processed through both eyes and are probably integrated in the brain's central complex, the presumed site of the sun compass.
- Time compensation is provided by circadian clocks that have a distinctive molecular mechanism and that reside in the antennae.
- Monarchs might also use a magnetic compass because they possess two cryptochromes that have the molecular capability for light-dependent magneto reception.
Source
" That millions of butterflies annually fly a few thousand miles to reach a cluster of pine groves in central Mexico comprising just 70 square miles is, for many, an awesome and mysterious occurrence."
Now, inn "Cryptochromes Define a Novel Circadian Clock Mechanism in Monarch Butterflies That May Underlie Sun Compass Navigation," published in PLoS Biology, Reppert and colleagues reveal that the circadian clock of the monarch uses a novel molecular mechanism, heretofore not found in any other insect or mammal." read more
here
Asher
