February 12, 2019

Dear friends,

Welcome all to the peak of an extraordinary Monarch season at the Sanctuaries Sierra Chincua and El Rosario in Angangueo, Michoacán, Mexico.

 

Every winter, scientists visit Mexico's 12 traditional sanctuaries and measure the area of forest covered by monarchs. In winter 2018/2019, the colonies covered an area of 6.05 hectares (as of December, 2018). They measure area because estimates of individual butterflies in a colony vary too widely to be reliable. Such estimates range from 10 to 50 million monarchs per hectare.