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Royalty in Indiana? Really? It’s true! Monarch butterflies have been summer residents in our great state for decades. Their distinctive coloring and pattern has made them a well recognizable around the world. Monarchs are also well-known for their amazing migration habits that have some butterflies traveling almost 3,000 miles to get to warmer climates.
The Life Cycle of the Monarch Butterfly
All butterflies will go through a complete metamorphosis in four stages –egg, larva, pupa and adult. For the Monarch butterfly, metamorphosis will take about a month.
A female will lay a single egg at a time, usually on a leaf of the milkweed plant. It is hard to determine how many eggs a female will lay in its lifetime, but it is believed the number is somewhere between 100 and 300. Eggs will hatch four days after being laid.
Once hatched, the butterfly enters its larval stage, commonly known as its time as a caterpillar. The Monarch caterpillar is distinguished by its bands of cream, yellow and black. During this stage, the caterpillar spends most of its time feeding on its singular diet of poisonous milkweed. This consumption of milkweed is built up so as an adult, the Monarch is poisonous to those that eat it – its one defense against predators. As the caterpillar gets bigger, it will molt (and then consume its shedding). This shedding occurs five times during the larval stage.
The next stage – the pupa stage – is when the caterpillar makes its greatest transformation. At this point, the larvae will encase itself in a chrysalis, a smooth, hard-shell casing where its body tissues and organs are broken down and re-arranged to create the adult. This is the Monarchs most vulnerable stage as it has limited ability to move if threatened by predators or adverse weather conditions. Thankfully its jade-colored casing is well camouflaged in order to elude potential threats.
When the Monarch materializes from its chrysalis, it emerges as a beautiful butterfly of deep orange, black and white. As an adult, their main duty is to reproduce, and will do so several times in their life. The monarch’s lifespan varies depending on when they emerge as a pupa and whether or not it will migrate. Those that are born in the early summer will have the shortest life – about two to five weeks. Monarchs that emerge in the late summer and migrate south will live much longer, around 8 – 9 months. Many of these Monarchs will experience the longest migration route for any butterfly in the world - a truly unique phenomenon.
From Here to There and Back Again:
The Monarch Migration
Every autumn, around three million Monarch butterflies will travel around 3,000 miles in order to mountains of central Mexico or to small groves of trees along California’s coast. But why? Monarchs are cold-blooded insects that cannot survive the long, cold winters of temperate climates. If these butterflies failed to take off, they will most likely perish. Their migration is a natural, survival instinct that has amazed people around the world as there is no other North American butterfly that migrates the way that most birds do.
There is a difference between butterfly and bird migrations. While most of the birds that fly south for the winter always return, butterflies do not. Instead the adults continue to mate and reproduce then die. It is their offspring (and their offspring’s offspring) that somehow know they must return north and how to do so. There are many questions researchers and scientists have about the Monarch butterfly that are left unanswered. For instance, how do those that didn’t make the trip south know how to get back north? Or how do following generations of Monarchs know exactly where to go to overwinter in the first placer?
According to Monarch Watch – a University of Kansas site dedicated to the education, conservation and research of the Monarch – overwintering sites are dependant on where the butterflies migrate from. Butterflies west of the Rocky Mountains will return to the California coast. Millions of monarchs east of the Rockies will migrate to the Transverse Neovolcanic Mountain Belt in central Mexico. Regardless of where they are overwintering, the sites are very similar. The most important element is trees where the monarchs can cluster together. The surrounding habitat – neighboring stands of trees, underbrush, stream, fog and water – is also necessary in order to protect the butterflies from wind and snow as well as provide moisture and a cool place as to not use up their reserved energy. Fir and pine stands are ideal overwintering sites.
In order to understand the migration instincts of the Monarch, researchers began tracking the butterfly. This ever-expanding project began in 1937 with F. A. Urquhart who began tagging the wings of the butterflies. The project grew as he started to enlist volunteers across the country in his Insect Migration Association. His research provided new information on where Monarchs overwinter in California. Although this particular project ended in 1977, many other organizations followed Urquhart’s lead and have continued monitoring Monarchs all over the world. Monarch Watch, Journey North and Monarch Alert are just a few of these organizations still working today.
Why Should We Care?
With millions of Monarchs in existence, it would sound foolish to say that they are in danger of being endangered. The truth is that there are many organizations, researchers and citizens concerned over the overwintering habitats Monarchs need in order to survive. There are only eleven to fourteen mountain tops in Mexico where these butterflies can find a safe haven to wait out the harsh winters in temperate climates. These areas are being targeted for new roads, housing developments and agriculture expansion. In the southern coastline of California, the stands of eucalyptus trees, Monterey pines and Monterey cypresses are in danger of being cut down due to the rate of land development in the surrounding area. If we do not concern ourselves with the possible destruction of these overwintering sites now, we may have to worry about the extinction of Monarch butterflies sooner than we would expect.
There are several organizations taking steps to ensure the protection of the Monarch's overwintering sites. Check out the World Wildlife Federation's Monarch Butterfly Conservation Fund, Papalotzin and its efforts to conserve the pine & fir stands in Mexico and Monarch Watch's Conservation page for more information.
Interesting Facts about the Monarch
Monarch butterflies are found throughout the U.S., in southern Canada, Caribbean Islands, Australia, New Zealand and other Pacific Islands.
The stages between the molting during the larval stage are called instars.
Monarch caterpillars only eat plants in the milkweed family.
There is little growth during the adult stage, but they still need food.
Monarchs mostly feed on the nectar of various flowers. Nectar is mostly sugar which is the butterfly’s primary source of energy.
Butterflies smell with their antennas, taste with their feet and sense sound in the veins of their wings.
Monarchs can cover about 80 miles a day while migrating for up to 3,000 miles total. No other butterfly will migrate the way the Monarch does.
Butterflies rest with their wings up. That is why Monarchs bold coloring is found on both sides of its wing, so it will always be displaying its warning to predators to stay way.
The milkweed poison built up in Monarch caterpillars and adults causes severe vomiting to animals that consumes it. There are a few exceptions, specifically black-headed grosbeaks and black-backed orioles, which can eat adult monarch butterflies in the overwintering colonies. While grosbeaks are relatively insensitive to the milkweed poison, the orioles have figured out which parts of the monarch bodies are safe to eat and avoid the most poisonous parts. Grosbeaks and orioles can kill more than 10% of the total monarch populations in a winter.
Facts gathered by Monarch Watch & the Monarch Butterfly Sanctuary Foundation.
For More Information
University of Kansas's Monarch Watch - an incredible resource for anything you ever wanted to know about the Monarch butterfly. Check out their Adopt-a-Classroom Program which helps provide educational materials and supplies to schools within the Monarch Reserve in Mexico.
Journey North's Monarch Butterfly site offers great information on Monarch migration and how you can participate in tracking Monarchs in your area. Their Spring 2008 season begins February 7th if your're interested in participating.
The Nature Conservancy's Monarch Butterfly webpage
The Science Museum of Minnesota's Monarch & Migration page has a number of wonderful ideas for educators and parents on how to teach their kids about Monarchs.
Monarch Butterfly of the USA - information on the life cycle and migration of the Monarch. A lot of interesting visuals and features suited for kids of all ages.
Nature picture credits (top to bottom, left to right): Photo © Mila Zinkova (Monarch cluster); Photo © TNC (Monarch); (); Photo © Derek Ramsey (monarch, egg-laying, caterpilla); Photo © Piccolo Namek (Viceroy); Photo © Curtis Clark (chrysalis). All images (besides TNC) found on Wikipedia. Permission was granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation or under the Creative Commons Attribution ShareAlike 2.5 License.
