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In The Country

Butterfly Blitz

Tim Iverson
Seasonal Naturalist
Cunningham Falls State Park

(8/2014) When you conjure up images of a butterfly you may think of one listlessly flapping its wings and gently gliding through the air, or perhaps it’s resting elegantly on a surface nearby. Chances are though the archetype you imagine is one with orange wings and black stripes. That butterfly would be the Monarch Butterfly. This proverbial king of the butterflies once reigned supreme, but troubled times rest at the throne for this regal insect. The Monarch Butterfly has an incredible life cycle and journey every year, and has proven its chops to the natural world through and through.

Monarchs will begin their annual life cycle in their overwintering sites in central Mexico. They spend their winters hibernating in fir forests. In February they’ll awaken and shake off that groggy feeling and immediately begin to seek out a suitable mate. Shortly thereafter they’ll begin their wayward journey to points north. Some will fly as far north as Canada and the adjacent border states. This will be the first of four generations in a calendar year. Sometime in March or April these butterflies will lay their eggs on milkweed plants in the northern latitudes they’ve journeyed towards. It will only take a few days for these eggs to hatch and this will begin the second generation.

This newly hatched caterpillar will spend approximately the next two weeks doing nothing but eating milkweed plants and seeking out more milkweeds to eat. Over the course of this time the toxins from the milkweeds will accumulate in the caterpillar causing them to taste foul to would be predators. After this 14 day gluttony binge the corpulent caterpillar will be ready to enter its next stage of development – the chrysalis stage! The caterpillar will attach itself to the plant leaf or stem using silk and transform into a chrysalis. From the outside things seem pretty lackluster, dull, or even stagnant. On the inside, however, there is a whole lot of change going on. Over the next 10 days rapid growth and development is underway! At the end a newly changed insect will emerge as a beautiful butterfly.

This second generation, born in May or June, will begin the process anew and will live its short life over a period of about two to six weeks. The third generation will be born in July or August and will go through the same life cycle and stages as the previous generation, while the fourth will be born in September or October. The fourth generation of the year is unique compared to the previous generations. This final generation will live considerably longer than the second and third generations. While the second and third live only a few short weeks, this last generation will become the first generation for the next year. Unlike the previous generations that die off after about two months this one can live for six to eight months. This generation is responsible for retracing the route south that their great-great grandparents followed north. They instinctively know to begin moving south when the weather begins to cool, and many even find the very same forests and trees that were used by their very own progenitors. The migratory instinct is poorly understood at the moment. There are a few theories about how it most likely works though.

Scientists believe that Monarch Butterflies, like turtles and birds, posses an inherited geomagnitc compass. This compass relies on the magnetic field generated by the earth which works like a built in GPS to tell them where to go. It is also reported that within their antennae there is a special protein that reacts with UV light emited from the sun. When the sunlight reaches a certain wavelength it sets off an internal alarm clock that tells them it’s time to move south. It’s at this point that their internal GPS, aided by the earth’s magnetic field, guides them to the overwintering sites that have been used by generations of ancestors before them.

There is some trouble in the kingdom though. All indicators point to steep population decline. Monarchs historically covered approximately 50 acres worth of fir forests at wintering sites in Mexico. Based on recent research conducted during 2011-2012 winter by the WWF-Telcel Alliance and the Mexican National Commission of Protected Areas it appears a total of nine colonies occupied about seven acres of total forest. A similar study conducted over the 2012-2013 winter showed a sharp decrease of Monarchs occupying just less than 3 acres of total forest. These are drastic decreases, and there are several factors contributing to these heavy losses.

Habitat loss is the leading contributing factor in the sharp drop in population. Milkweed is exclusively what the Monarch caterpillar feeds on. Increased use of pesticides at farms, along roadsides, and at home has taken its toll. Milkweed tends to grow on roadsides, fields, and prairies. Development over decades has destroyed much of this valuable land. The use of new genetically modified crops allows farmers to use new pesticides that have destroyed millions of acres of milkweed.

Another issue causing problems is a plant known as the Black Swallow-Wort. The introduction of this non-native European plant is taking its toll. This plant is a relative of the milkweed, and has similar features which attract Monarchs to lay their eggs on this plant. However, even though it is in the same family it is actually toxic for monarch caterpillars and poison these newly hatched larvae. They say that imitation is the sincerest form of flattery, but this imposter is wreaking havoc on an already unstable population. These two compounding factors, along with some natural disasters along migratory routes have attributed to the spiraling population size for this royal butterfly.

The alarming rate that this butterfly is disappearing has raised some to action, and you too cannrally to the cause. Monarch Watch, based out of the University of Kansas, is a nonprofit education, conservation, and research program that focuses on the monarch butterfly, its habitat, and its spectacular fall migration. They host a citizen scientist project that allows interested people to sign up for population monitoring. They also provide tiny little stickers that are placed on the wings of the butterfly (when done correctly will not cause any harm or detriment to the bug). These stickers allow researchers in Mexico to see where these butterflies are migrating from, and they will update a website so you can see if your butterflies made it all the way there!

Milkweeds are the host plant for the Monarch butterfly and occur naturally throughout the continent. Planting more of these in our area and yards will greatly increase the likelihood of regional success. By planting areas of milkweeds you can create "way stations" that will provide necessary resources for their long term survival. These habitats can be planted in home gardens, schools, along roadways, and any where there is open and available land. The greater number of way stations that are created and maintained the greater the chance of survival Monarch Butterflies will have.

For most people the quintessential image when we conjure up a butterfly in our heads is the Monarch. With a little help from us it may be able to continue to flutter and fly through the sky, but that will require some leg work from us. Seek out opportunities at state and local parks to get involved and learn about projects that can have a positive impact on our natural world. This king of the butterflies needs some help to restore the throne, and with some small tangible gestures we just may be able to do so.

Read other articles by Ranger Tim Iverson