In late October and early November, millions of orange and black monarch butterflies will descend on the high-altitude pine, fir and oak forests of the Monarch Butterfly Biosphere Reserve in Mexico’s Michoacán State. Up to a billion of the insects will overwinter in the forests, clustering together by the thousands to conserve heat in clumps so heavy they can bend or snap tree branches. After mating in February, the butterflies disperse, traveling north through the rest of Mexico, the United States and Canada to breed on milkweed plants through the spring and summer.
The butterfly colony is one of the natural wonders of the world, but that hasn’t stopped illegal loggers from encroaching on the 200-square-mile preserve. That’s why last week a special police unit raided the area, shutting down seven sawmills. A squad of 220 policeman and 40 foresty inspectors backed by a helicopter raided the logging camps, reports the Agence France-Presse.
The squad permanently shuttered three illegal sawmills in the town of Ocampo and temporarily closed one while they verify its paperwork. Three other sawmills in the town of Aporo were temporarily closed because of a lack of paperwork. The authorities also seized 231 cubic feet of illegally harvested wood.
Ignacio Millan Tovar, a deputy prosecutor at the federal environmental prosecutor's office, tells the AFP that the raid takes 3,300 cubic meters of wood out of circulation. "It is the equivalent of 330 logging trucks lined up one after the other," he says.
Last April, the Mexican government announced the creation of a Federal police force charged with protecting the country’s natural areas and enforcing environmental laws. This raid is believed to be the first action by that new police force.
The government conducted similar raids in 2007, reports the Associated Press. During those roundups, the police closed over 70 illegal sawmills and arrested 250 people near the butterfly reserve.
Following the raid, illegal logging in and around the reserve declined to almost zero by 2012, according to another AP report. But logging in the reserve resumed and by 2014 had tripled in numbers. In 2015, illegal loggers destroyed 49.4 acres of forest in the reserve area, much of it in critical monarch habitat. And before the most recent raid, loggers had impacted 29.6 acres this year—a fact that environmentalists discovered using drones.
The monarch numbers have greatly fluctuated over the years. In the past, the insects could cover almost 44 acres of forest while overwintering. That dropped precipitously to 1.33 acres in 2013 and 2.8 acres in 2014. The last census, taken in December 2015, however, was cause for celebration: The butterflies covered over ten acres of forest.
But March storms this year showed just how vulnerable the reserve is. High winds and rain destroyed 133 acres of the forest, and a cold snap killed about 6.2 million of the 84 million monarchs reports the Associated Press. An earlier storm in 2009 destroyed 262 acres of the forest. Conservationists worry that climate change is making these damaging storms more frequent and so preservation of the forest is becoming increasingly critical.
“This points up just how fragile these forests are, and how fragile the monarchs are, and it makes clear the importance of reforestation efforts,” Omar Vidal, director of WWF Mexico tells the AP. “This is why we insist that illegal logging in the reserve has to be eliminated, and that the destruction of [the butterfly’s] milkweed habitat in the United States has to be stopped, so that the monarchs have the ability to better respond to these extreme climate events.”