Question and Answer

How many monarchs are in one overwintering colony in Mexico?

Each of the sites that monarchs occupy in the Monarch Butterfly Biosphere Reserve are different in size. Scientists measure the size of each colony or overwintering site by measuring the area of the trees/land that is occupied by monarchs. With these measurements, they use an estimate of between 10-50 million monarchs per hectare of land occupied.

Back to Frequently Asked Questions