A modest uplift for the Monarchs

A Monarch butterfly tried to run me off the sidewalk this weekend. He failed. (We’re in very different weight divisions.) But I was happy to see him.

In the 1980s, millions of Monarchs flew south from as far as British Columbia and wintered in California, but those numbers have declined radically since then, roughly 10 percent a year. They are now a species on the brink. Because the butterflies must follow a nectar-rich path on their annual migrations, they are a kind of gauge of the health of the entire ecosystem along their route.

But there is good news from the other side of the Rockies. The population of Eastern Monarchs that winters in Mexico bounced back 64 percent this year. The 7.2 acres of forest they mobbed was the biggest area for their annual jamboree since 2018. The population level is not yet what experts consider sustainably stable, but it’s moving in the right direction.

Source: World Wildlife Fund Mexico; the Xerces Society