Michoacán, Mexico (The Butterfly Forest)
I Tried to Count the Monarchs One by One
Monarchs covered 64% more forest in Mexico this winter. Scientists measure the trees. I tried counting butterflies.
Every winter, monarch butterflies cluster in the forests of central Mexico. This winter they covered 2.93 hectares, up 64%. Scientists don’t count each butterfly. They measure how much forest the clusters cover. I tried counting them one by one.
My Count
1, 2, 3. Easy. Butterflies are beautiful and slow, at first.
41. One flew away. Do I subtract it? I subtracted it.
112. Two more landed on my hat. Do I add them? I added them. Then they left. I’m now at 109, or maybe 112.
About 300. A whole tree of them took off at once. I started again from one.
“A lot.” My final count, after one hour. Very scientific.
The Scientists’ Way
The scientists walk around the edge of each cluster with GPS and work out the area of forest it covers. That’s much smarter. The butterflies keep moving, but the trees stay exactly where they are.
Their number: 2.93 hectares of butterflies. My number: a lot. I think we agree. Either way, it’s good news: the colonies grew, after a summer up north with less drought. Welcome back, everybody.
Frequently Asked Questions
How far do monarchs fly?
Thousands of miles, from the United States and Canada down to Mexico, on wings like paper. I complain about a two-hour flight.
Did any land on you?
Two of them, on my hat. They have excellent taste.