
This is an extract from “
Miraculous Migration”, written by Carol Crupper.
Monarchs that survive the winter in the fir forests of Mexico fly north to Texas, seeking mates and milkweed plants on which to lay eggs.
More generations follow, breeding through spring and summer and living just two to five weeks before the butterflies reach Canada. In the fall, the fourth generation completes the cycle, flying south at a pace of 25 to 30 miles per day. Some third-generation butterflies join the migration, too, and these long-distance travelers live for up to nine months.
The phenomenon involves masses of butterflies, each behaving individually, confronting the vagaries of weather and ever-changing landscape without parents and leaders to guide them, and processing only rudimentary brains. How they manage this journey remains a mystery to mankind, but anyone who witnesses the mass migration is thankful for a glimpse at the nature’s sustaining rhythms.
In mid-October, monarchs converge in south-central Texas and follow the river bottoms between Eagle Pass and Del Rio. Taylor, a professor of insects ecology at University of Kansas says, “It’s like a river of butterflies as far as you can see, coming right at you. It is the most spectacular phenomenon in the planet.”
The phenomenon is in danger, however.
To survive, the monarchs need milkweed, a native plant that is disappearing from farmland and along highways at the rate of 6000 acres per day. Taylor cites herbicides, rampant development and roadside management policies that destroy food and shelter. “We have lost 147 million acres of habitat since I started in 1992, more than 3 times the size of the state of Illinois,“ he says.
In addition, Taylor attributes the loss of wintering habitat in Mexico to deforestation and changing weather patterns. Severe storms two winters ago claimed at least 50% of the insects, although this year’s mild weather helped the monarch population to begin to rebound.
As a species, the monarch does not face extinction. Populations are healthy west of the Rocky Mountains and on other parts of the planet. Losing this unique North American migration would leave a global void, however. Not only is the cycle breathtakingly beautiful, “ it all feeds into this complex web of life, ” Taylor says.
While efforts are underway to implement a government-supported conservation plan among North American nations to restore milkweed and nectar plants for monarchs, people who value the migration have initiated their own preservation efforts.
Since its founding, Monarch Watch has developed a vast network of volunteers and spread awareness of the monarch’s migration and plight. The organization sponsors butterfly tagging programmes in 37 states and 5 Canadian provinces. Participants also plant milkweed and nectar plants in 4500 habitats in 44 states.