Reading Practice
The dingo debate
Graziers
see them as pests, and poisoning is common, but some biologists think
Australia’s dingoes are the best weapon in a war against imported cats and
foxes.
A
A plane flies a slow pattern over Carlton
Hill station, a 3,600 square kilometre ranch in the Kimberley region in
northwest Australia. As the plane circles, those aboard drop 1,000 small pieces
of meat, one by one, onto the scrubland below, each piece laced with poison;
this practice is known as baiting.
Besides 50,000 head of cattle,
Carlton Hill is home to the dingo, Australia’s largest mammalian predator and
the bane of a grazier's (cattle farmer's) life. Stuart McKechnie, manager of
Carlton Hill, complains that graziers’ livelihoods are threatened when dingoes
prey on cattle. But one man wants the baiting to end, and for dingoes to once
again roam
Australia’s wide-open spaces. According to Chris Johnson of
James Cook University, ‘Australia needs more dingoes to protect our
biodiversity.’
B
About 4,000 years ago, Asian sailors
introduced dingoes to Australia. Throughout the ensuing millennia, these
descendants of the wolf spread across the continent and, as the Tasmanian tiger
disappeared completely from Australia, dingoes became Australia’s top
predators. As agricultural development took place, the European settlers found
that they could not safely keep their livestock where dingoes roamed. So began
one of the most sustained efforts at pest control in Australia’s history. Over
the last 150 years, dingoes have been shot and poisoned, and fences have been
used in an attempt to keep them away from livestock. But at the same time, as
the European settlers tried to eliminate one native pest from Australia, they introduced
more of their own.
C
In 1860, the rabbit was unleashed on
Australia by a wealthy landowner and by 1980 rabbits had covered most of the
mainland. Rabbits provide huge prey base for two other introduced species: the
feral (wild) cat and the red fox.
The Interaction between foxes, cats and rabbits is a huge
problem for native mammals. In good years, rabbit numbers increase
dramatically, and fox and cat populations grow quickly in response to the
abundance of this prey. When bad seasons follow, rabbit numbers are
significantly reduced - and the dwindling but still large fox and cat
populations are left with little to eat besides native mammals.
D
Australian mammals generally reproduce much
more slowly than rabbits, cats and foxes - and adaption to prevent overpopulation
in the arid environment, where food can be scarce and unreliable - and
populations decline because they can’t grow fast enough to replace animals
killed by the predators. Johnson says dingoes are the solution to this problem
because they keep cat and fox populations under control. Besides regularly
eating the smaller predators, dingoes will kill them simply to lessen
competition.
Dingo packs live in large, stable territories and generally
have only one fertile, which limits their rate of increase. In the 4,000 years
that dingoes have been Australia, they have contributed to few, if any,
extinctions, Johnsons says.
E
Reaching out from a desolate spot where
three states meet, for 2,500 km in either direction, is the world’s longest
fence, two metres high and stretching from the coast in Queensland to the Great
Australian Bight in South Australia; it is there to keep dingoes out of
southeast, the fence separates the main types of livestock found in Australia.
To the northwest of the fence, cattle predominate; to the southwest, sheep fill
the landscape. In fact, Australia is a land dominated by these animals - 25
million cattle, 100 million sheep and just over 20 million people.
F
While there is no argument that dingoes will
prey on sheep if given the chance, they don’t hunt cattle once the calves are
much past two or three weeks old, according to McKechnie. And a study in
Queensland suggests that dingoes don’t even prey heavily on the newborn calves
unless their staple prey disappears due to deteriorating conditions like
drought.
This study, co-authored by Lee Alien of the Robert Wicks
Research Centre in Queensland, suggests that the aggressive baiting programs
used against dingoes may actually be counter-productive for graziers. When
dingoes are removed from an area by baiting m the area is recolonized by
younger, more solitary dingoes. These animals aren’t capable of going after the
large prey like kangaroos, so they turn to calves. In their study, some of the
highest rates of calf predation occurred in areas that had been baited.
G
Mark Clifford, general manager of a firm
that manages over 200,000 head of cattle, is not convinced by Allen’s
assertion. Clifford says, ‘It’s obvious if we drop or loosen control on
dingoes, we are going to lose more calves.’ He doesn’t believe that dingoes
will go after kangaroos when calves are around. Nor is he persuaded of dingoes’
supposed ecological benefits, saying he is not convinced that they manage to
catch cats that often, believing they are more likely to catch small native
animals instead.
H
McKechnie agrees that dingoes kill the
wallabies (small native animals) that compete with his cattle for food, but
points out that in parts of Westers Australia, there are no fixes, and not very
many cats. He doesn’t see how relaxing controls on dingoes in his area will
improve the ecological balance.
Johnson sees a need for a change in philosophy on the part
of graziers. ‘There might be a number of different ways of thinking through
dingo management in cattle country,’ he says. ‘At the moment, though, that
hasn’t got through to graziers. There’s still just on prescription, and that is
to bait as widely as possible.’
Questions 1-7
Reading
Passage has eight sections, A-H.
Which
sections contains the following information?
Write
the correct letter, A-H, in boxes 1-7 on your answer sheet.
NB You may use any letter more than once.
1..................... a description of a barrier designed to
stop dingoes, which also divides two kinds of non-natives animals
2..................... how dingoes ensure that rival species do
not dominate
3..................... a reference to a widespread non-native
species that other animals feed on
4..................... a mention of the dingo’s arrival in
Australia
5..................... research which has proved that dingoes
have resorted to eating young livestock
6..................... a description of a method used to kill
dingoes
7..................... the way that the structure of dingo groups
affects how quickly their
numbers grow
Questions 8-10
Look
at the following statements (Questions 8-10) and the list of people below.
Match
each statement with the correct person, A, B, c or D.
Write
the correct letter, A, B, C or D, in boxes 8-10 on your answer sheet.
8..................... Dingoes tend to hunt native animals rather
than hunting other non-native predators.
9..................... The presence of dingoes puts the income of
some people at risk.
10..................... Dingoes have had little impact on the
dying out of animal species in Australia.
List of People
A Stuart
McKechnie
B Chris
Johnson
C Lee
Allen
D Mark
Clifford
Questions 11-13
Complete
the sentences below.
Choose
NO MORE THAN TWO WORDS from the
passage for each answer.
Write
your answers in boxes 11-13 on your answer sheet.
11. The
dingo replaced the 11.....................
as the main predatory animal in Australia.
12. Foxes
and cats are more likely to hunt native animals when there are fewer
12.....................
13. Australian
animals reproduce at a slow rate as a natural way of avoiding
13.....................
Solution:
1. B 8. D
2. D 9. A
3. C 10. B
4. B 11. Tasmanian
tiger
5. F 12. rabbits
6. A 13. overpopulation
7. D
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