Where community and environmental literacy come together:
Relax. Sit down. Enjoy. Connect.

February 11, 2014

Monarch Butterflies in Trouble

"On the first of November, when Mexicans celebrate a holiday called the Day of the Dead, some also celebrate the millions of monarch butterflies that, without fail, fly to the mountainous fir forests of central Mexico on that day. They are believed to be souls of the dead, returned." (1)
"This year, for or the first time in memory, the monarch butterflies didn’t come, at least not on the Day of the Dead. They began to straggle in a week later than usual, in record-low numbers. Last year’s low of 60 million now seems great compared with the fewer than three million that have shown up so far this year. Some experts fear that the spectacular migration could be near collapse." (1)  2013's migration had the lowest number of Monarchs on record and the downward trend in the population is truly a cause for concern and rectifying action.  Scientists are truly worried that within a few years the great migration of the Monarch to Mexico may be over.
Part of this decline may be attributable to the irresponsible and excessive use of pesticides across the United States which directly kill the Monarch Butterflies or compromise their health and ability to fly the many hundreds of miles on their remarkable journey.  Neonicotinoids, a neuro-toxic family of insecticides developed by Shell and Bayer, are strongly implicated in the decline of honey bees and likely have detrimental effects on butterflies as well.  That these compounds are neuro-toxic should cause humans pause, seeing how we have neurons too. 

Particularly detrimental to the Monarch's habitat, the use of herbicides that kill all plants except genetically modified crops designed to survive the onslaught.  This practice has destroyed much of the milkweed populations which are the sole food on which the larvae feed.  "One study showed that Iowa has lost almost 60 percent of its milkweed." (1)

Another cause contributing to the decline of Monarchs is the loss of native vegetation along their migratory route.  Especially in recent years where '"the price of corn has soared....driven by federal subsidies for biofuels, farmers have expanded their fields. That has meant plowing every scrap of earth that can grow a corn plant, including millions of acres of land once reserved in a federal program for conservation purposes." (1)
Additionally, people living along the migratory route of the Monarchs are developing the land at a rapid pace, replacing fields with houses, highways and parking lots, while planting lawns and plants that may have brightly attractive colors, but which are unusable for Monarchs.  This loss of land and appropriate nutrition may be causing the butterflies to die of exhaustion or malnourishment or might make them more susceptible to disease.  Numerous watch groups for the butterflies and other beneficial insects encourage homeowners to plant native flowers that will actually give sustenance to the butterflies as they make their migratory journey! 

Migratory Route of Monarch butterfly

Besides the fact that Monarchs are important pollinators for our crops and for native flora and despite that they are mobile links that connect resources and services between ecosystems, why should we care that we might be seeing the end of one of the greatest annual insect migrations in the world?  How about the value of wonder and insights into the mysteriousness of life?

"In North America they make massive southward migrations starting in August until the first frost. There is a northward migration in the spring.  The monarch is the only North American butterfly that migrates both north and south as the birds do regularly, but no individual makes the entire round trip." (2)  Sometimes the roundtrip migration can take as many as 4 or 5 generations.

Think about that for a minute.......  Say it's August for a Monarch in Iowa.  Somehow  our brave butterfly can tell the time of year and realizes that it's time to go.  How does she know it's time to go?  No one knows, but she starts travelling South.  Maybe she gets to Kansas where she lays an egg on a milkweed before dying.  The larvae hatches and grows into a butterfly and somehow she knows that she needs to be migrating too.  Not only that she needs to migrate, but where ever she finds herself she knows exactly what direction to go.  She flies further south and perhaps makes it to South Texas where she lays an egg on a milkweed plant before dying.  The next generation grows up and picks up right where her mother left off and flies to a specific forest in Mexico where all the migrating Monarchs from the East United States converge at nearly exactly the same time no matter if they started in Iowa or Maine, Mississippi or North Dakota.  No matter where they migrated from up North they converge in this forest in Mexico almost always on or near the Day of the Dead celebration that takes place on October 31, November 1 and November 2.  How do they know where to go?  How can they have such a remarkably precise sense of time?  How does one generation know where to pick up where the previous generation left off? 


Scientists know that Monarch Butterflies are astronomers.  They keep track of the position of the sun in the sky and use it as compass adjusted to a circadian clock in their antennae.  Additionally, "new research has also shown these butterflies can use the earth's magnetic field for orientation. The antennae contain cryptochrome, a photoreceptor protein sensitive to the violet-blue part of the spectrum. In the presence of violet or blue light, it can function as a chemical compass, which tells the animal if it is aligned with the earth's magnetic field, but it cannot tell the difference between magnetic north or south. The complete magnetic sense is present in a single antenna." (2)

But despite all of these sensory organs, it still doesn't elucidate how the butterflies use these tools to get where they need to go or how they know where to go.  This multi-generational migration is a personal symbol of mine for having a purpose and a sense of meaning, for though each butterfly may not know why it is where it is or why it has the urge to travel, it is fulfilling a greater purpose which is the great migration of the Monarch.

An appropriate variation on a cliché might be, 'you don't know what you've lost until it's gone.'  But what's worse is the fact that we might lose a butterfly that has a story that inspires wonder, study, inquiry and mystery.  How many other species might be lost from this world preventably, by our actions, whose life story could reveal incredible insights into what it means to be alive?

-Seth Commichaux

No comments: