The Twelve Sanctuaries

To estimate the size of the monarch population, scientists travel to all 12 major overwintering sites and measure the surface area the butterfly colonies cover. The measurements are done in December, and the task can take two weeks. The annual population estimate is the sum total area of all 12 sites.

Map of The Twelve Monarch Sanctuaries in Mexico


Journey North Home Page   Facebook Pinterest Twitter   Annenberg Media Home Page
Copyright 1997-2017 Journey North. All Rights Reserved.   Contact Us    Search