Groups file to list monarchs as endangered; With 90 percent decline in popular butterfly species, groups say time to act is now
The Center for Biological Diversity, Center for Food Safety, the Xerces Society and monarch scientist Dr. Lincoln Brower filed a legal petition Tuesday to the U.S. Fish and Wildlife Service seeking Endangered Species Act protection for monarch butterflies.
Monarch enthusiasts say increasing use of pesticides and, especially, destruction of key milkweed habitat have become major threats to the iconic orange and black butterfly. They estimate that over the past 20 years, monarchs have lost about 165 million acres of habitat, an area about the size of Texas.
“Monarchs are in a deadly free fall and the threats they face are now so large in scale that Endangered Species Act protection is needed sooner rather than later, while there is still time to reverse the severe decline in the heart of their range,” Brower said in a prepared statement announcing the petition.
Georgia Parham, a U.S. Fish and Wildlife Services spokeswoman, said the agency has 90 days to respond on whether the petition is warranted. It probably would take several years to complete a process if the agency determined it is needed. She noted that several insects, including some species of butterflies, already are on the list.
The Center for Biological Diversity says the monarch butterfly’s dramatic decline is being driven by the widespread planting of genetically engineered crops in the Midwest, where most monarchs are born. The use of specific herbicides in corn and soybean fields that kill milkweed has been a particular problem. Milkweed now is nearly nonexistent in areas of heavy corn and soybean production, the group notes.
“Without milkweed, you don’t have monarchs. Females will only lay eggs on milkweed and the (monarch) caterpillars will only eat milkweed,” said Tom Uecker, a retired Duluth teacher who has been raising and releasing monarch butterflies for nearly 40 years.
Uecker plants milkweed and has milkweed seeds that he gives away to anyone willing to plant them.
“Milkweed is great for all pollinators, like bees, and many pollinators are in big trouble,” Uecker said. “Milkweed is also a native plant, a native wildflower. It’s not a weed at all. We need to get people to plant more of it.”
Uecker noted that 2013 saw the lowest migratory monarch population on record. While monarch populations appear to have increased a bit this summer compared to last year, he said the longer-term decline in monarch numbers has been striking.
“You can’t help but notice how few there are now,” he said.
In addition to the loss of milkweed across the Midwest, Uecker said some pesticides that target other species may also be killing monarchs. He said an insecticide that targets gypsy moth caterpillars, for example, also has killed monarch caterpillars. And Uecker said illegal logging in Mexican forests where monarchs spend their winters also has hurt the overall population.
Observers say monarchs also are threatened by global climate change. Scientists have predicted that the monarch’s entire winter range in Mexico and large parts of its summer range in the United States could become unsuitable due to changing temperatures and increased risk of drought, heat waves and severe storms.
Monarch butterflies are known for their multigenerational migration each year from Mexico to northern Minnesota and back. In winter most monarchs from east of the Rockies converge in the mountains of central Mexico, where they form tight clusters on just a few acres of trees.
The population has declined from a recorded high of about 1 billion butterflies in the mid-1990s to only 35 million butterflies last winter, the lowest number on record.
Scientists say monarchs need a very large population to be resilient to threats from severe weather events and predation. Nearly half of the overwintering population in Mexico can be eaten by birds and other predators during the course of a winter. One Mexican storm in 2002 killed an estimated 500 million monarchs, far more than currently exist.
For more information about monarch butterflies, go to monarchwatch.org.