The Monarch Butterfly, known for its bright flashy colors, is a very common species found in North America. You might think this creature is fragile and delicate, but read on to see why this tiny little flapper is so special and spectacular.

You are probably aware that a lot of animals and birds migrate every year in the winter to warmer places and return back in the summer. I bet you did not know that these Monarch Butterflies travel over 2500 miles every year to beat the freezing winters.

The migration of monarch butterflies begins in fall from Canada and the northernmost part of the United States. A million monarchs from the eastern part of the Rocky mountains migrate to Texas and Mexico; whereas monarchs from the western part of the Rocky mountains migrate to California. In spring, these butterflies return back to their summer homes up in the north.

So, why do butterflies have a need to migrate? Cold temperatures below 55ºF make it impossible for them to flutter their wings and temperatures below 40ºF paralyze them. To you, it means you need to put on your leather jackets and gloves, but to the butterflies this means certain death as they wont be able to fly and gather food. This is the reason they fly south during winter to beat the freezing cold and to find food.

Then why do they fly back north in spring? Butterfly larvae thrive on milkweed plants which are abundant up north. This is is why they migrate north in Spring where they reproduce in thousands. Also, the summer heat in the south is too hot for them and hence they fly back north where it is cooler.

Migration is a one way journey for all monarchs. This means that the butterflies that traveled south in the fall reproduce and die, and their great grand-children complete the northward journey. In spite of the fact that it is their fourth generation that completes the return journey, these butterflies return to exactly the same spot every year flying over 2500 miles. No one knows how the monarchs manage to do this, but it is something amazing.

If the temperature is below 60ºF, they huddle up in big clusters in the branches of their roosting tree. Once in the cluster, they conserve and share the heat to keep each other warm by spreading out their wings and covering the monarch next to them. They arrive in California by end of November and leave by the end of March.

By December and January, when the weather is the coldest, their clusters could contain hundreds or upto thousands of monarchs. They pick a strategic location high up in the tree which gets the sun’s first rays in the morning and last rays in the evening thereby utilizing the sun’s heat to the fullest.

By mid-February, these clusters break up completely and the monarchs flutter around to gather nectar. In the spring, they reproduce and their offspring will make the return trip to the north. The male monarchs are recognized by the two dots on their lower hind wing. The female monarchs are recognized by their thick black veins on their upper wing.

Monarch butterflies, in spite of being flashy, colorful and an easy target are avoided by most of their predators as the milkweed they eat growing up, produces a toxin called alkaloid in their bodies which has a very bitter taste. To some predators, the monarch butterfly or their larvae are considered poisonous.

When the sun comes out and it gets warmer, these butterflies break out from their clusters, spread their wings, soak in the sun and regain their energy to fly around and gather food.

There are numerous groups actively studying and researching the migration behavior of the Monarch butterflies. One of the methods used to track the route these butterflies take is to tag them by placing an information sticker on the bottom of their hind wing. The picture above was taken in Pacific Grove, CA and shows a butterfly that was tagged up somewhere in Canada. It proves that this butterfly successfully made the long migration trip to the south.

Steven has excellent pictures that capture the life cycle of the monarch right from the eggs, caterpillar, chrysalis to the butterfly. Here is his excellent photo stream: Monarch Love

As for the title of this post, the monarchs left California last month and are fluttering up north towards their summer home.