Every winter, millions of monarch butterflies from the eastern part of North America migrate south to a forest in the middle of Mexico, where they see out the season until fall comes.
The forest, which was first discovered in the 1970s, is officially called the Monarch Butterfly Biosphere Reserve, and has been a protected site in Mexico since 1980. But ever since then—and likely before—the forest has remained threatened by illegal logging.
On Tuesday, Mexican authorities announced steps towards fighting that threat, in the form of the closure of seven sawmills that had been operating illegally in the reserve, according to the Associated Press.
The closures come around two months ahead of the butterflies’ arrival and amid a wider crackdown on illegal logging in the area.
The total preserve is some 215 square miles, or about the size of Chicago. But a smaller, core area of the zone is where officials have focused their efforts, almost cutting in half the amount of illegal logging there from 2015 to 2016, according to the AP.
All of which is good news for the monarchs, who need all the help they can get. Their populations have declined massively in the last 10 years, and scientists still aren’t quite sure how—or if—they can be saved.