EXPLORING BIODIVERSITY: A Guide for Educators Around the World

Animals are more prone to extinction
if they:
Are naturally rare. Some animals, including
many of the world’s large ones, are rare even in
the places they normally live. Others live only in
a few places and nowhere else. As more people
move into the area, many of these already rare
plants and animals face habitat loss, competition
from introduced species, new diseases, and
other problems.
Have small ranges, very specific food or
nesting patterns. Some animals are very picky
about what they eat or where they live, or both.
These specialised animals, which are often
adapted to eating only one type of food or
living in only one type of area, can become
threatened if their food source or nesting site
disappears. Animals that can live only in
very specialised habitats don’t have many areas
to retreat to if humans or natural disasters
threaten them.
Migrate. Animals that migrate usually depend
on several different habitat areas. Because of this,
they face many impediments, and habitat
destruction can make them especially vulnerable.
For example, many songbirds that migrate
between tropical and temperate forests are in
trouble because thousands of acres of their habitat
have been developed into pastures, farms,
towns, and roads.
Live only on islands. Many island animals have
adapted to the absence of predators, so they are
particularly susceptible to exotic species introduced
by humans. For example, a number of
SPECIES AT RISK
flightless island birds such as the dodo have
been forced to extinction because, when
humans first came to their island, the birds were
not afraid of and could not escape the new
predators (humans, dogs, and pigs).
Are very sensitive to change. Many animals
have a difficult time adapting to changes in
their environment. For example, predatory
birds and mammals are very sensitive to
chemical changes in their habitats, such as the
introduction of pesticides. These poisons concentrate
in predatory animals from every other
animal or insect that they eat.
Produce few offspring and have long gestation
periods. Ask the kids if they can think of
some animals that give birth to only one or two
young every year or every two or three years
(elephants, bats, condors, and so on). Explain
that when the populations of these animals
drop, it takes much more time for their populations
to recover because of the low birth rate.
These animals sometimes become extinct before
they have time to make a comeback.
Are used for food or medicine. In some parts
of the world, wild animals are hunted for food
or to make traditional remedies. When populations
are already small due to habitat loss, or
when the trade in these animals reaches a large
scale, species can become threatened.
Interfere in some way with people’s activities.
Some animals, such as jaguars or wolves,
may occasionally kill livestock. Because they
interfere with human activities, large predators
are sometimes killed.
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