Mexico’s monarch butterflies are suffering from an usual cold weather system that began two days ago with severe rain, wind, and cold temperatures battering butterflies to the ground. As snow falls in the Monarch Biosphere, conservation of the other end of the monarchs’ life is criticized as inadequate. U.S. conservation groups today issued a suit against the government for failing to protect the monarchs under the Endangered Species Act.
Although some monarchs have left the Biosphere and begun migrating to their summer ranges, none has been seen yet entering Texas, which means they are still flying along the spine of the Sierra Madre mountains included in the winter storm. The cold wet weather and high winds have created conditions that are deadly to the one-half or more of this year’s population still remaining in the Biosphere. Snowfall today may benefit the butterflies by insulating the clusters hanging from trees, but many will die anyway. The 8 to 13 inches of snow in El Rosario and adjacent villages hasn’t been seen since the 5 inches that fell in 1995 and caused a population crash, although the population then was nearly double this season’s.
People living near the Biosphere also suffer from cold as their homes are not built for this weather and they lack heating and sufficient blankets. These people have shifted their lifestyles to protect the butterflies. They are dependent now on ecotourism instead of forest trees for their income and the handy source of firewood is no longer legal to cut. Tree seedling nurseries and reforested areas help ensure the monarch’s habitat and a new visitor’s center with food and crafts vendor spaces was just completed. As much as the monarchs depend on clement weather to survive, now so do the human residents.
Two weeks ago these monarchs were cheered as the largest overwintering population in five years. They are responsible for the entire population summering in the US and Canada east of the Rocky Mountains. Their summer homes aren’t secure enough, either, but many of these problems can be addressed if proper actions are taken. Lack of such action is the focus of a lawsuit issued today.
The Center for Biological Diversity (CBD), Center for Food Safety and others (such as monarch researcher Dr. Lincoln Brower and The Xerces Society) are suing the U.S. Fish and Wildlife Service for not following through on legal deadline to issue a final decision regarding the petition to list the monarchs under the Endangered Species Act (ESA).* An announcement issued today by CBD describes the reason for the lawsuit.
Center for Food Safety, the Center for Biological Diversity and allies formally petitioned the Service in August 2014 to protect the monarch as a “threatened” species following a 90 percent population decline over the preceding two decades. In December 2014 the Service determined that protection may be warranted, triggering an official review of the butterfly’s status that, by law, must be completed within 12 months. More than a year later, however, the Service has failed to issue a final decision on whether to protect the charismatic orange and black butterfly under the Act. Today’s lawsuit requests that the court set a deadline for that decision.
The deathly weather in the Biosphere today speaks to how threatened are these butterflies and is coincidentally mirrored in CBD’s announcement (my bold added).
While this year’s winter count is better than the record lows of the previous three years, it still represents a decline of 78 percent from the known population highs of the mid-1990s and is well below the population size needed for recovery. Monarchs require a much larger population to be resilient to severe weather events and other threats. A single winter storm in 2002 killed an estimated 500 million monarchs — more than three times the size of the entire current population.
Studies conducted by scientists and conservation groups point to several threats that can be altered if the legal basis through the ESA exists to enforce actions.
The butterfly’s dramatic decline has been driven in large part by the widespread planting of genetically engineered crops in the Midwest, where most monarchs are born. The vast majority of genetically engineered crops are made to be resistant to Monsanto’s Roundup herbicide, which is a potent killer of milkweed, the monarch caterpillar’s only food source. The dramatic surge in Roundup use and “Roundup Ready” crops has virtually wiped out milkweed plants in midwestern corn and soybean fields. It is estimated that in the past 20 years these once-common butterflies may have lost more than 165 million acres of habitat — an area about the size of Texas — including nearly a third of their summer breeding grounds.
Monarchs are also threatened by global climate change, drought and heat waves, other pesticides, disease and predation, urban sprawl and logging on their Mexican wintering grounds.
We can’t turn back climate change induced threats fast enough to benefit the monarchs and many other species, but we can limit harmful pesticides, habitat losses, and practices like captive breeding and release and careless use of non-native milkweeds.