Animal Migration
 Animals migrate for any number of reasons, to exploit
an abundant food resource, to breed, to give birth in ideal conditions
for optimal survival, and to escape predation. Many different classes
of animals migrate, from birds and fish, to mammals and even insects.
The animal that holds the record for the longest migration is the
Arctic tern, which flies over 20,000 miles each year from pole to
pole and back. The gray whale
is the mammal that migrates the longest, swimming over 12,000 miles
each year to give birth and breed in the warm waters off Baja California
and then to feed in the nutrient rich waters off Alaska. The most
studied insect migrant is the Monarch butterfly, which summers in
North America and winters in remote mountain tops of central Mexico.
Animal migrations have evolved over millions of years and are a critical
element in the life cycles and survival of these animals. |
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Rest Area Closed
Unfortunately,
humans are changing the face of the earth, the bounty of the oceans and the temperature of
the planet so rapidly that many animals cannot adapt. Traditional stopover areas on these
incredible journeys have been wetlands, fields, shorelines and forests in which to
replenish energy through rest and feeding. However, many wetlands have been drained,
fields developed and forests cut. Populations of migrating animals are finding fewer and
fewer areas to stop. Even when an animal makes a successful journey, often the location to
which they have historically migrated may be drastically altered. The greater the
depletion of resources, of course, means less and less of a population will survive. |
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Monarchs Deposed
In the case of the
Monarch butterfly which depends on encountering suitable habitat at many points along its
migration route, conditions are deteriorating. This will limit the number of Monarchs who
will survive the journey to Mexico. Once they reach their destination, they will find that
many of the remote mountain tops have been deforested, sprayed with pesticides and have
been affected by air pollution due to an ever-growing population. It is estimated that
Monarchs may only survive another 10 to 20 years because of these changes. |
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Barrier Ahead
Other examples of
animals that are finding it much more difficult to survive during their annual migrations
are salmon due to dams and siltation; turtles due to entanglement in fishing nets and
development on beaches; and even land animals which encounter barriers where once there
were none and depletion of resources in the face of the rapidly expanding human
population. |
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What To Do? So what can be done? Lots, if we all do our part! Here are a few suggestions: · Adopt a wetland or nearby field as a
school project. Work to pass laws to provide permanent protection. · Build and put up bird nesting boxes · Landscape your yard in a wildlife
friendly manner by planting native flowering and fruit producing plants and trees. Provide
water for birds in natural or artificial bird baths. · Reduce your consumption of energy,
materials and water. Encourage your city to pass conservation measures and reward those
who use less. · Protect wildlife nesting areas, like
swamps, forests and turtle nesting beaches. · Limit the size of your family after you
marry. · Educate your friends about what you
have learned. |
