Open Magazine - Index

Open Magazine - magazine - Index

Cover Story
Magical
T H E
Journey
by Paul Justice
In the world of natural science, one of the great unsolved
mysteries is that of the migration of monarch butterflies.
Dr. Fred Urquhart, from the University of Toronto, Scarborough
College, solved part of the mystery. He spent more than three
decades trying to answer the simple question, “Where do
the monarch butterflies go in the winter?” Urquhart tagged
hundreds of monarchs in Canada and spent years in Mexico
trying to solve the mystery. In January 1976, an elderly Dr.
Urquhart sat beneath an Oyamel fir tree laden with butterflies,
feeling completely devastated that the end of his life may come
before he had a firm answer to his question. Suddenly, an
overhead branch, covered with hibernating butterflies, broke,
showering him with hundreds of monarchs. To Urquhart’s great
delight, one of the butterflies had one of his tags on its wing.
This gave the elated Urquhart the first positive proof
that monarchs from Canada spend their winter
in the high pine and fir forests of central
Mexico. (National Geographic,
August, 1976)
The Unbelievable Methuselah Generation
of Monarch Butterflies
The majority of monarch butterflies have a lifespan of
about four to five weeks, but monarch butterflies born in
September and early October instinctively are part of the
‘Methuselah’ generation and have a life span of approximately
seven to eight months. The Methuselah monarch butterflies
that are born east of the Rocky Mountains are destined to
make the 5,000 kilometre migratory flight from Canada to
Central Mexico. At an average speed of 13 kilometres per hour,
this precarious journey takes six to eight weeks. The monarch
butterfly, with its brilliant orange and black wings, is one of
the most delicate members of the insect world but it is also
one of the most resilient. Despite this, many are unable to
complete the journey south. A rain or hail storm can tear their
wings if protective cover is not found in time. Some predators,
such as wild turkeys, are immune to the monarchs’ poison
and eat them. Unable to withstand the arduous journey,
some monarchs simply die from exhaustion. (http://secure.
worldwildlife.org/monarchs)
By the end of November, the monarch butterflies are
congregated at 3,000 metres above sea level in the Oyamel
fir forests. With the cool temperatures associated with high
elevation, their metabolism slows dramatically, allowing them
to survive until spring. In late January and February, the warm
sun infuses life into the colonies and the air becomes a riot of
colour as monarchs drink water from streams and collect nectar
from a variety of wildflowers. Some monarchs will mate and
die in the sanctuaries. The end of March finds the sanctuaries
vacated as the Methuselah generation completes its final leg of
the journey and heads for Texas, where they will mate and die.
The successive four or five generations of butterflies that have
never been to Canada and the northern United States continue
to fly northward. The cycle of mating and dying is like a relay
race of generations maintaining the timeless pattern
that science fails to fully understand. (www.
monarchwatch.org)
Like many other species in the
world, the very existence of monarch
butterflies is threatened by
interference by humans. One of the
greatest threats is the decimation of
forests in, or adjacent to, the overwintering
sanctuaries. They need to
hibernate in forests, close to, but just
above freezing temperatures. The forest
acts as an umbrella to keep the hibernating
butterflies dry and provides a blanket to
keep them warm. During the past 20 years,
the forest cover near the sanctuaries has been
seriously reduced due to illegal commercial
logging and by local residents who cut the
trees for timber for building materials and