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Extinction of Species
Large predators may be exterminated because
they kill livestock. Wolves are often hunted because they kill
sheep. Wild animals and plants may be collected for sale as
pets or for use in research. Many die when they are captured,
while they are being transported or in captivity. For example,
128 million tropical fish were imported to the USA in 1980.
A reduction of the population of species is
not always caused directly by killing the organisms through
hunting or fishing. Sometimes human activities destroy the
habitats of living organisms. The habitat of an organism is
its home: where it lives, feeds, and reproduces. If an
organism's habitat is a deciduous forest, for example, and
humans cut down the forest to make farmland or build houses,
the organisms living in the forest will die if they cannot
adapt to the changes or find a new place to live. Many species
have become extinct because humans have destroyed or modified
their habitats, polluted their environment or introduced new
species to an area.
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Examples
of organisms removed from tropical regions by humans -
parrots,
orchids and tropical fish. |
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©
Paul Billiet, Shirley Burchill, Alan Damon and
Deborah James 2009 |
The Open Door Web Site
