THE MYSTERY OF THE MONARCHS

 

 

One of the profoundest mysteries of the natural world is the annual trans- continental odyssey of the Monarch butterflies from Canada, across the United States to Mexico. Caterpillars blossoming into beautiful butterflies perform an aerial feat of endurance and navigation without prior experience. It is their first flight to an unknown area following something – wind, sun – yet they reach their destination every year at precisely the same time, a feat unique in the animal kingdom (butterflies are animals, not insects). They start usually one at a time, then the air is saturated with them, the startling contrast of their bright pattern immediately recognizable.

 

 

The process begins late on August north of Lake Huron in Canada. Tiny caterpillars already exhibit circular bands of the monarch’s variegated colors. In an amazing transformation they will grow and shed their skin 4 times while, within a delicate case, a completely new being is formed. In 10 days they will lose all traces of caterpillar and turn into a 4 winged butterfly with interconnecting stripes:  black with white polka dots, yellow and  black precisely designed interconnecting stripes. Their wings harden in a few hours then the flight of 100 million begins their migration. From Southern Canada, through northeast United States, 2000 miles and two months later to Mexico.

 

 

The reverse process began 3 generations earlier when a group left Mexico at the end of  winter.Then in one month they flew to the U.S. mated in Texas laying  300 – 500 fertilized eggs which continue the journey mating and dying every month on the way until the 4^th generation reaches its original starting place in Canada a full year later. The fourth generation lives nine months and flies back to Mexico. What triggers the annual exodus is unknown.

 

A Monarch’s wingspan is 4”, its weight less than 1/5 oz. How do they survive migration? They only fly when the conditions are perfect, when it’s too hot they stop flying, when it’s too cold their wings become sluggish, they make infrequent stops for nectar, their natural enemies are spider webs, bad weather like deadly rainstorms. They fly south to avoid death of cold winter. Pesticides kill many pf them. Decreased amount of trees in the forests and  illegal logging another threat.

 

The sun provides a magnetic field, and their brain cells regulate an internal clock and keeps them on course. They must fly 50 miles per day which requires a huge physical effort and their aerodynamic design is poor. They must soar to conserve energy, and fly thermal winds currents like a glider.

The Great lakes are their first trial with miles of water and shifting winds. They stop and wait on ships’ surfaces until conditions are right, then there is  the scorching desert heat, and the Sierra Madre Mountains.

 

Their ultimate destination is 60 square miles, 10,000 feet high in Mexico where the waiting Mexicans are celebrating “the day of the dead”. They believe the butterflies are the spirits of their loved ones and they build alters of flowers and fruits for them. In October they light candles and pray for their safe arrival  giving rise to businesses in small towns the Mexicans need to survive the rest of the year. They finally arrive the first week of November after 2 months and thousands of miles. They fill the skies and  cover the vegetation, millions of them and there are great celebrations in the towns.

 

 

There are 12 specific sites within the 60 miles which have perfect conditions: heat from trees and the land while the forest supplies the umbrella. The Mexicans protect their trees for this reason. Now they rest in clusters, clinging to the trees for warmth for 5 months when they bloom again opening their wings to the sun. Writers and scientists have been inspired to study them. In 1975 scientists first discovered the extent of their migration by tagging them.

In 1992 a Monarch watch began when Chip Taylor of the University of Kansas had kids tag the Monarchs revealing travel speeds and flight paths. In an experiment relocating them to D.C. they still managed to find the original flight path using different vectors to get on track traveling through small Western towns and the Great Plains of the Southwest.

I have tried to research, unsuccessfully, an explanation for the presence of the Monarchs on Fire Island. They should be here as you read this. Too bad we can’t ask them. Just enjoy this amazing phenomenon.

 

Monarch butterflies do migrate along Fire Island. The number of butterflies
seen at park sites last fall seemed to be less that normal, according to
one of our rangers in the field.
From the Journey North site, they have a record of 200 monarchs in a 10½
hour period on September 16, 2008:
Click Here

Paula S. Valentine
Public Affairs
Fire Island National Seashore

 

Jeannie Lieberman

              Images courtesy of US Fish & Wildlife Service

 

P.S. My research did find this disturbing advertisement:

Special Sale! 20% off Monarch Butterflies CLICK HERE