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The monarch
is one of the most beautiful butterflies. It is famous for its yearly migration(迁徙)from the northern part of North America to Mexico, There, millions of
monarchs spend the winter together in one small area. This migration is one of the
greatest wonders of nature. Yet this behavior has now put the monarch at risk.
Every
September, millions of monarchs from the United States fly to Mexico. After about
two months of flying time, they reach their sanctuary(庇护所)in central Mexico. Then, in the warm climate of private and quiet valleys,
far from most human activity, the butterflies create one of nature's great scenes.
They cover every tree with bright color. The show lasts until spring, when the butterflies
return north.
While
they are all crowded together, the monarchs are highly weak. If the environment
in those valleys was disturbed, the whole species could be hurt or even die out.
That is why for many years scientists who knew about the monarchs' winter sanctuary
kept the location a secret.
In recent
years, however, the monarchs' secret has been discovered. Today, the butterflies'
winter sanctuary is crowded with tourists, who disturb the environment. Worse still,
local farmers who need more land to farm have begun to take up the area. They are
cutting down trees, making it difficult for the butterflies to survive. They should
not farm in the monarchs' sanctuary.
People
should act immediately to protect the species' winter sanctuary. Local farmers must
be helped so that they no longer need to take land from the butterflies. Tourist
visits to the butterflies' hidden valleys must also be limited. Unless these steps
are taken soon, in a few years the monarch butterfly of North America may be just
a beautiful memory.