A colorful insect that has long been a source of wonder is now a source of worry.
Monarch butterflies have been admired by generations of humans for their beautiful orange-and-black coloration, the beneficial pollination services they provide and the long migrations they make to Mexico at the end of each summer.
Those migrations are getting underway, which means monarchs will be winging their ways south through Missouri in the weeks ahead. However, recent data indicates seeing one of these colorful insects isn’t as common an event as it used to be.
Studies have shown monarch butterfly numbers east of the Rocky Mountains have declined by approximately 90 percent in the last 20 years. The U.S. Fish and Wildlife Service equated that population drop to a loss of approximately 970 million butterflies during that time span, but the Center for Biological Diversity described the reduction in more sobering terms. It said, in human population terms, the monarchs’ population drop is equivalent to losing every living person in the U.S. except for residents of Ohio and Florida.
This alarming population drop is the reason monarchs have been in the news in recent years here in Missouri and elsewhere. The Missouri Department of Conservation is one many agencies and organizations throughout the central and eastern U.S. that are involved in efforts to increase habitat for monarch butterflies and other pollinators.
The importance of these projects goes far beyond insuring that humans will continue to be able to see pretty butterflies in their flower gardens. Studies have shown the financial benefits provided to U.S. citizens by butterflies and other pollinating insects can be measured in the billions of dollars.
As mentioned earlier, now is when monarch migrations in the eastern U.S. are getting underway. The timing of this annual migration is theorized to be linked to changes in the amount of daylight (photo period) that begin to occur at this time of year. The variabilities of day and night temperatures that take place at this time of year probably also trigger the migrations to Mexico.
One of the big mysteries of the migration is how do monarchs find the same site – a specific area in the mountains of central Mexico – each year. No monarch makes a migratory trip more than once. Since none of the monarchs headed for Mexico have ever made the trip before, how do they end up at the same location year after year? One theory is that monarchs use the earth’s magnetic field to guide them to this specific area. Another theory is that they are guided by the polarization of the sun’s rays.
While these are just theories, it’s a fact that now is the time to see migrating monarchs. Milkweed is a monarch favorite, but they can also be seen around other flowering plants. Although it’s too late to plant a butterfly garden for this year, it’s not too early to start planning one for next year. The Missouri Department of Conservation booklets “Butterfly Gardening and Conservation” and “Milkweeds and Monarchs” have good information on what to plant and how to attract specific butterfly species. These free publications are available at many Missouri Department of Conservation offices.
On Sept. 16, the Missouri Department of Conservation’s Springfield Conservation Nature Center will have a “Monarchs Rule For Families” program from 1 p.m. to 3 p.m. This program is for ages 5-adult. Registration begins Sept. 1. To register or to get more information, call 417-888-4237.
Monarch butterfly information can also be found at missouriconservation.org.