Students Book

3
Natural health
Read and listen
Passive report structures
Vocabulary: health and medicine
Vocabulary: feelings
a What do you know about animals’
behaviour when they are ill?
b Read the article quickly and find out:
1 which places are mentioned in the text.
2 what similarities scientists noticed
between humans taking medication
and the chimpanzee Hugo eating the
leaves of certain plants.
When animals are ill
According to recent research in biology, chimpanzees in the
wild are thought to choose certain herbs and use them as
medicines when they are not feeling well. After studying
how chimpanzees eat the leaves of specific bushes and trees
in Tanzania, two scientists, Paul Newton of the University
of Oxford and Toshisuda Nashida of the University of
Kyoto, concluded that there are striking similarities between
how these animals eat these plants and how humans take
their medicines.
Until recently, only humans were believed to be able to
make intelligent decisions when it comes to curing illnesses.
But that was before the two scientists carried out their
research in the Gombe National Park in Tanzania. They
noticed that a chimpanzee they called Hugo was behaving
differently from the other animals. He was picking the
leaves from a bush that does not usually make up part of
the chimpanzees’ diet. The bush is called aspilia, and it has
very sharp leaves, which is precisely why chimpanzees don’t
usually eat them.
What was surprising was the way Hugo ate the plant. He
not only picked it very carefully, he also rubbed the leaves
before he put them in his mouth, and then he kept them in
his mouth for a little while before he swallowed them. This
is exactly how humans take medicine! What was even more
surprising for the scientists, though, was that the very same
plant that the chimpanzee selected is known to be used by
local people as a medicine when they feel unwell!
Newton and Nashida were also surprised to find that
when chimpanzees take this ‘medicine’, they only do so
in the morning, whereas normally they would feed in the
afternoon. They believe that they do this because the level of
medication in their body has decreased overnight. Another
explanation is that these wild animals look for the juice of this
bitter plant for the same reason that humans drink a cup of coffee
in the morning – to help them wake up and give them energy!
In her book, Wild Health: How Animals Keep Themselves Well
and What We Can Learn From Them, author Cindy Engel gives
several other examples of how animals treat health problems.
According to her, it’s not only plants they use as medication.
Elephants in western Kenya, for example, are said to go regularly
at night-time to a cave on the side of Mount Elgon, an extinct
volcano. Once they are in the cave, they use their tusks to break
off parts of the soft rocks, crunch them in their mouths, and
then swallow them. For a long time, little was known about the
reasons for this behaviour, but recently scientists have discovered
that the rocks contain a high level of sodium, which is needed
to help neutralise the toxins that elephants are known to take
in with their plant diet. The behaviour of these elephants and of
other animals shows that they have developed amazing abilities
to care for their own health – without any doctor having told
them what medication to take!
Discussion box
1 What conclusions do you draw from
reading this article?
2 Would you like to be a scientist studying
animal behaviour? Why / Why not?
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UNIT 13