March 23, 2012
Monarch Butterfly Population Continues To Decline
A Texas A&M researcher has found evidence that the population of Monarch butterflies continues to shrink.
Craig Wilson is a senior research associate in the Center for Mathematics and Science Education and a longtime butterfly enthusiast. He says, according to reports from the World Wildlife Fund, Mexico´s Michoacan State and a host of private donors, that the numbers of Monarch butterflies that cross the state of Texas will be dramatically reduced, by as much as 30%.
These numbers are part of a sad decades-trend in declining numbers of Monarch butterflies. This long and downward decline has Wilson concerned, saying it would be best “that we take the long view rather than yearly cycles.”
In a press release, Wilson stated: “The latest information shows that Monarchs will be down from 25 to 30 percent this year, and that has been part of a disturbing trend the last few years.”
“Last year´s severe drought and fires in the region no doubt played a part, resulting in less nectar for the Monarchs as they migrated south. But estimates show that each year, millions of acres of land are being lost that would support Monarchs, either by farmers converting dormant land for crop use — mainly to herbicide tolerant corn and soybeans — or the overuse of herbicides and mowing. Milkweed is the key plant because it´s the only plant where the female will lay her eggs.”
Researchers have been keeping a close eye on the extreme land conditions in Texas and the effects these conditions have on the Monarch butterfly population.
“Chip Taylor, who is the director of Monarch Watch at the University of Kansas, estimates that 100 million acres of land have already been lost that previously supported Monarchs,” Wilson notes.
The majority of the Monarch reserves are located in Michoacan, Mexico, according to Wilson. These butterflies will spend the winter months in this area and mate before making their grand migration north. When the spring arrives, the Monarchs leave Mexico and fly through Texas, laying their eggs in the milkweed plants and feeding on nectar. Adult Monarchs will take various routes through Texas as they make their way north. The offspring of these butterflies will travel much further north, often as far as Canada.
According to Wilson´s research and data from Texas Monarch Watch, there will be fewer butterflies to make their journey across the Lone Star State. Last year, Monarch butterfly breeding grounds covered 9.9 acres of forest in the Michoacan State of Mexico. This year, that number was down to 7.14 acres, reinforcing a downward trend that has been occurring since official population surveys began in 1994.
These disturbing numbers have Wilson calling for a national effort to save the Monarchs before their numbers dwindle even further.
“We need a national priority of planting milkweed to assure there will be Monarchs in the future,” he says. “If we could get several states to collaborate, we might be able to promote a program where the north-south interstates were planted with milkweed, such as Lady Bird Johnson´s program to plant native seeds along Texas highways 35-40 years ago. This would provide a ℠feeding´ corridor right up to Canada for the Monarchs.”