WATER!
"Basically the entire mountainside is as dry as a bone at this time of year, and the butterflies are forced out of the colonies to drink," explains Dr. Bill Calvert.
The dry season began in November. By March it is so dry that hardly any water is available for the butterflies to drink in the form of dew or rain. The monarchs fly down the mountains in search of water.
At first, scientists did not realize that water is important for monarchs at this time of year. It took many years of study before they learned that the watersheds of the overwintering sites needed to be protected, too. Imagine monarchs surviving all winter in their colonies only to perish in March due to lack of water.
Photo:
Dr. Lincoln Brower, Sweet Briar College
Notice
the dust in this picture!
The
mountains in Mexico's monarch overwintering area are volcanic, and the
volcanic dust is as fine as baby powder. People often cover their mouths
so they can breathe.
Do
these pictures make you feel thirsty, too?
(Click pictures to enlarge.)
Photos: Dr. Lincoln Brower, Sweet Briar College