Return
of the monarchs
Photo by Rene (Surf’s Out)
THE
MYSTERY OF THE MONARCHS
by Jeannie Lieberman
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 4th 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.
Monarch butterflies do migrate along Fire Island 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.
The migration here on Fire Island this year seems to be NOW
(August 19. 2012).
From the Journey North site, they have a record of 200 monarchs in a 10½
hour period on September 16, 2008:
Images courtesy of US Fish & Wildlife Service
P.S. My research did find this disturbing advertisement:
Special Sale! 20% off Monarch Butterflies
http://www.butterflyreleasesbys.com/
for more info:
Paula S. Valentine
Public Affairs
Fire Island National Seashore
Jeannie Lieberman, editor
Theaterscene.net
Publisher, Fire Island Sun. com
