Have you ever been driving along in your car along the beach road in the late fall and seen what looks like a miniature football fan flying through the air and about to hit your windshield? Relax, it’s not a crazed fan that has had too much cheer and fallen off the bus but rather a monarch butterfly heading south for the winter. No, they are not from Michigan.
The Monarch (Danaus plexippus) is common around here this time of year, though it is now at the very end of their season with us. The adult monarchs are bright orange with black edges running around their wings and black veins throughout. The body is black with white spots. You can tell the boys from the girls by the dark spot on the hindwings that are called scent scales.
Besides it coloration one very interesting thing about the monarch is that it is poisonous – not deadly poisonous but any animal that eats it will get sick. The monarch gets its poison when it is in its larval stage by eating a plant called milkweed. It is called milkweed because its sap is thick and milky white.
Farmers consider the milkweed a plant pest and they are glad to see the Monarch around. Milkweed and other plants in its family contain a compound from a group called glycosides, which are all poisonous.
Any plant, animal or insect that is highly visible like the Monarch and lives long enough to reproduce is giving out a very strong sign to stay away from it. A counter example of this would be any animal that is an albino.
They usually do not live long enough to reproduce and potential mates avoid them because they are different. The poisonous Monarch is mimicked in nature by the non-poisonous North American Viceroy butterfly. It has a very similar shape, color and pattern. I guess it goes to show that if you look like you’re dangerous people will leave you alone.
The females lay their eggs along the way and it takes up to three generations of Monarchs to complete the migration. Some Monarchs do not migrate at all and live out their entire lives in the same small area. Once monarchs reach their final destination they can be found by the tens of thousands, concentrated in a very small area. Some buildings in San Diego, California have their air conditioning systems clogged with them.
Monarchs are found throughout the world in subtropical areas to include the United States, Canada and Mexico. Some Monarchs migrate over 2,000 miles during August through October, going from Canada and the U.S. to spend the winter in Southern California and central Mexico.
Think Globa – Act Local