As an expression of concern by scientists and conservationists, a letter was delivered to President Barack Obama regarding the decline of monarch butterflies. Among the researchers who signed this important letter was WMU professor of biological sciences, Dr. Stephen Malcolm. The huge decline in monarch numbers appears to be an indicator of problems with agricultural policy in the US and Canada and deforestation in Mexico. The number of monarch butterflies wintering in Mexican pine and fir forests has plunged to its lowest level since studies began in 1993. The famous butterflies this year covered just 1.65 acres, or 0.68 hectares, providing further evidence that the monarch's annual migration from Canada to Mexico is in danger of disappearing.
"The overwintering decline to less than a hectare is truly alarming," Malcolm says. "There's a lot of buzz on the Internet about this decline, the reasons for it and the implications of such a huge decline." Overwintering monarchs in Mexico have gone from covering about 21 hectares in 1996-97 to about 0.68 to 0.67 hectares this winter, Malcolm says. Last year, the butterflies covered about 1.21 hectares, almost double the total this winter. Malcolm says the monarchs have been weathering a perfect storm of adverse factors, including habitat destruction, wider use of genetically modified, herbicide resistant corn and soybeans and extreme weather.
The decline is alarming because they are a good indicator of broad, ecosystem imbalances caused by policies that need to be researched and regulated more effectively. Migratory monarchs move across the landscape of NAFTA and are the symbol of the CEC, the environmental component of NAFTA, based in Montréal. Thus, the butterfly should act as a symbol of responsible and sustainable economic development. Instead it is a symbol of serious environmental degradation in which not only monarchs are declining but so are pollinators and other beneficial insects such as predators and parasitoids of agricultural pests.
"There's a huge network of citizen scientists, who are really engaged in monarch butterfly biology and doing all sorts of things to try to enhance the environment for monarch butterflies and they are truly alarmed," Malcolm says. "It's such an iconic insect that there's a huge amount of affection and interest throughout North America. It's not just the U.S.A., it's Canada and Mexico, too. We wrote a paper more than 20 years ago about endangered phenomena like butterfly migration and it's pretty clear that that paper was prophetic that this migration is endangered. It's a threatened phenomenon. It's threatened west of the Rockies and east of the Rockies." According to Malcolm, the latest findings show how serious the problem is. "Monarchs won't go extinct, but migratory monarchs could. We wouldn't see monarchs anywhere north of the Gulf Coast." Audio clips can be heard of Dr. Malcolm discussing the decline of monarch butterflies at wmich.edu/news/radio.