Monarch Butterfly

Images from Wikimedia Commons

If you live in the continental United States, you've probably encountered a Monarch Butterfly (Danaus plexippus). Their range literally covers the country and a large chunk of the rest of the continent as well. They've also made their way over to Europe, Australia, and New Zealand due to lucky wind systems and cross oceanic shipping.

The Monarch was one of the species initially classified by Linneaus in 1758's Systema Naturae, and its scientific name comes strait out of mythology. In short, Danaus was a king and had 50 daughters, while his brother, Aegyptus, had 50 sons. Aegyptus wanted the 50 sons to marry the 50 daughters but Danaus refuses until he gets forced into organizing a mass wedding. He then has his daughters kill their husbands, and all but one does. The remaining son gets revenge on Danaus, and he and the daughter become king and queen to a dynasty. See where all this royalty stuff comes from? (Oh, and the species name, plexippus, comes from a name of one of the sons) It has also been speculated that the "Monarch" name is to honor King William III of England (William the Orange in his Dutch Homeland). This is interesting because the butterfly was not called "Monarch" until 1874, while William III ruled 1689-1702, nearly two hundred years earlier.

Wintering Monarchs

Anyway, mythology/history lesson aside, the Monarch butterfly is of particular interest to many due to their migration. Butterflies west of the Rockies travel to the California coast in order to survive the winter. But Monarchs east of the Rocky Mountains can travel upwards of 3,000 miles in order to arrive at congregation spots in Mexico. The generation that roosts all winter then lays its eggs on the return journey. It can take multiple generations to make the trip back to the original northern homeland, while it takes only one generation to make it to Mexico. Scientists and amateurs alike track and study these migrations each year.

And last but not least, Monarch Butterflys are poisonous. And where do they get that toxicity from? Their diets of course! They consume milkweed which gives them high concentrations of cardenolide, which is harmful to most predators.