How do Species become Extinct?
Almost all extinctions today are caused by human activity. The three
main human activities are Habitat loss, Introducing
Non-Native Species and Hunting and Harvesting:
Habitat loss
The biggest cause of extinctions is from species losing their homes,
or habitat. Clearing forests,
draining wetlands, damming rivers, turning grasslands into farming areas
and putting human structures in the natural environment all remove natural
habitat. Most species are adapted to a specific habitat and cannot live
anywhere else.
Introducing Non-Native Species
Most of the worst pests in Australia have been introduced from other
countries by people. These animals and plants do not have any natural
predators so they often spread
very fast and take over habitat and food sources from native
species. Rabbits, foxes, cane toads and blackberries are examples of
introduced species. Many native species have become endangered
or extinct because they have
been killed, had their food eaten or lost their habitat due to introduced
species. You can help by never letting any pets or aquarium fish into
the wild.
Hunting and Harvesting
Some animals, like rhinos, tigers and bears are hunted in the wild for
their skins, tusks and other products. Many of these large animals take
a long time to reproduce and so are very close to extinction. Sea animals
like whales and seals are also hunted for their meat and skins, while
overfishing has caused many of the world’s fish species to decline in
large numbers.
World Wildlife Fund, 2002.
More information on Overfishing.
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