Study: Monarch Butterflies Colonies Continue To Decline In Mexican Hibernation Spots

By Murphy Woodhouse
Published: Monday, March 1, 2021 - 12:03am

Monarch butterflies
Murphy Woodhouse/KJZZ
Butterflies fill the sky at the Piedra Herrada Sanctuary in Mexico.

Monarch butterfly colonies in Mexico are continuing to decline.

When the temperature drops in the United States and Canada, the butterfly species heads south to the pine forests of Michoacan and Mexico State. But this year, their colonies occupy just over 5 acres, a 26% decline from the year before. That’s according to a new study from the World Wildlife Fund.  

The organization attributes the decline to ongoing deterioration of the temperate forests where the butterflies hibernate every winter. Illegal logging is one of the principal factors behind that degradation. Climate swings also impacted the flowering of milkweed, which the monarch larvae depend on, according to a release from the organization.

The group is urging collaboration between Mexico, the United States and Canada to address the threats facing the species.

Fronteras Science Sonora