The monarch butterfly is in grave danger.
A recent study found the number of monarchs hibernating in Mexico had reached an all-time low, a World Wildlife Fund (WWF) news release reported.
Only 1.65 acres of Mexican forest was inhabited by hibernating monarchs in December of 2013, that's a 44 percent drop since only the year before. The numbers are the lowest they have been since the beginning of the annual survey in 1993.
The number of hibernating monarchs in the forests of Mexico indicates how many of the insects have made the 2,500-mile migration from Canada and the U.S. A number of factors are believed to have led to the monarchs' recent decline. Their reproductive habitats and hibernation grounds have been greatly reduced; herbicides have killed a great deal of milkweed, which is primary food source for monarch larvae. Extreme climate conditions are also believed to have made an impact.
"The combination of these threats has led to a dramatic decline in the number of monarch butterflies arriving to Mexico to hibernate over the past decade," Omar Vidal, WWF-Mexico Director General, said in the news release. "Twenty years after the signing of NAFTA, the monarch butterfly migration - a symbol of cooperation between our three countries - is in grave danger."
WWF has asked that officials in Canada, Mexico, and the U.S. work out an emergency plan to save the dying species and preserve their migration.
Almost all monarchs that hibernate in Mexico grew up eating milkweed. Researchers believe the majority of monarchs come from the Midwestern U.S. "Corn Belt." This reproductive habitat has been largely damaged by crops that allow "post-emergence treatment" with herbicides.
"These genetically modified crops have resulted in the extermination of milkweed from many agricultural habitats," Karen Oberhauser, professor at the University of Minnesota and monarch expert said in the news release.
"In addition to habitat degradation due to use of pesticides and herbicides, recent changes in federal law in Canada have significantly reduced protection of monarch butterfly habitat across Canada," Doctor Phil Schappert, Canadian butterfly conservationist and author who lives in Halifax, Nova Scotia, said. "The promotion of 'the economy first' practices, instead of sustainable land use practices, threatens monarch habitat."
Over the past few decades Mexican officials have worked to protect the butterflies' hibernation grounds, but to no avail. It is important that the U.S. and Canada take the same protective measures in order to save the species
"Considering the challenges faced by the monarch butterfly and the clear evidence that their populations are declining, it is vital to mobilize as many people as possible, and that our efforts are carefully planned to help this butterfly recover, so their wonderful migration can be appreciated for many more generations," Oberhauser said.