Monarch Butterflies: One of the World’s Greatest Migrations Plummets

Monarch butterflies are powerful representations of life.

There is no doubt that these beautiful creatures have significant meanings to many people.

Sadly, the number of monarchs that  completed their annual migration to their winter home in a Mexican forest this year sank tremendously. According to officials, they are at their lowest level in at least two decades. Once as large as 50 acres, the forest where the colonies of butterflies usually migrate has dwindled down to about 2.94 acres. That’s a 59 percent decline from the 7.14 acres of butterflies measured in December 2011.

The most recent overwintering population in Mexico covered nearly 0.67 hectares of forest–an all-time record low.

This sharp decline is due mostly to altered farming practices and extreme weather.

“We are seeing now a trend which more or less started in the last seven to eight years,” Omar Vidal, the head of the wildlife group’s Mexico operations, said in an interview. “Although insect populations can fluctuate greatly even in normal conditions, the steady downward drift in the butterfly’s numbers is worrisome.”

In 2012, the monarchs arrived to their breeding ground too early. The record-breaking heat and drought in the US also caused them to head farther north than usual. Chip Taylor, director of the conservation group Monarch Watch at the University of Kansas, said that their early arrival disrupted the breeding cycle. The hot weather ended up drying out their eggs and lowering the nectar content of the milkweed they feed on.

Another source of their decline is attributed to the alarming increase of genetically modified corn and soybean crops throughout the American farmland. Created to tolerate herbicides, the practice has wiped out much of the milkweed typically found within the millions of acres of crops. Even the conservation reserves and grasslands that once supplied the monarchs with food have been depleted.

“That habitat is virtually gone. We’ve lost well over 120 million acres,” Taylor told The New York Times.

The record-low census doesn’t necessarily mean that monarchs are doomed, but if they were to reach a tipping point, there may be no turning back.

“Normally, there’s a surplus of butterflies and even if they take a big hit, they recover,” explained Taylor. “But if their current 2.94-acre wintering ground drops below 2.5 acres, bouncing back could be difficult.”

What many people see as a marvel, naturalists around the world regard the butterflies as a direct indicator of the health of the food chain. Fewer butterflies does not mean good news.

The Mexican government has since halted their massive illegal logging efforts in the monarchs’ winter home. Conservationists and state and local governments will also hopefully be able to replenish some of the milkweed lost to development and changed farming habits to enable the colonies to prosper.

“This is one of the world’s great migrations,” Taylor said. “It would be a shame to lose it.”

Yes, it most certainly would.