The number of monarch butterflies completing their famous migration to central Mexico is dramatically shrinking. Every spring, hundreds of millions of butterflies east of the Rocky Mountains fly up to 3,000 miles to winter in central Mexico
But this year, migration numbers shrunk to the lowest level in decades.
In 2011, the butterflies occupied 7.17 acres of forest. December 2013, it was just 2.94 acres — a decrease of 59 percent.
Although, butterflies crossing the border don’t go through checkpoints or carry visas, their journey is still influenced by a complicated cross-border relationship between the U.S. and Mexico.
The migrating monarch population has been declining for close to two decades. It is now just one-fifteenth the size it was in 1997.
During much of this time, internal logging within the mountainous forests in Central Mexico was decimating the wintering butterfly population.
At it's peak in 2005, logging destroyed 1,140 acres in the reserve.
But in the past few years Mexico has taken pro-active and effective steps to combat the logging problem. Armed police have been assigned to patrol the reserve; groups started planting new trees and building tourist facilities.
When news broke Wednesday about the diminishing migrating population the focus was no longer on Mexico’s forests, but instead on the practices of U.S. farmers.
Experts are saying the negative impact on migrating butterflies begins long before they reach the southwest, or Mexico. It begins on Midwest plains. Via the LA Times:
The American Midwest’s corn belt is a critical feeding ground for monarchs, which once found a ready source of milkweed growing between the rows of millions of acres of soybean and corn. But the ubiquitous use of herbicide-tolerant crops has enabled farmers to wipe out the milkweed, and with it much of the butterflies’ food supply.
Another problem is climate change.
So, Mexico has taken steps to protect the butterflies – will we?
The cross-border butterfly dilemma brings to mind a project here at the San Yisdro port of entry, the world's busiest land border crossing.
It was a bilateral project with a common goal, much like protecting the butterfly migration would be.
A year after breaking ground, Mexico finalized construction. But in the U.S. there's a familiar narrative of delay.
Construction on the U.S. side is delayed. We're waiting on federal funds, which need to be appropriated by congress. And in the current political climate of sequestration, it's hard to tell when these funds might be coming.
Butterflies and the port of entry share one thing — economic incentives for improvement prevail on the Mexican side. On the U.S. side, not so much.
In Mexico, the migration of butterflies brings in millions of tourist dollars, which creates an incentive for action. But the U.S. is essentially the "fly-over" zone for the butterflies, and they bring in no revenue, so little or no incentive to change. Likewise at the border, border security concerns and political gridlock continue to delay the creation of a more efficient frontier.