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. 19

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. 22 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. 17 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. 16

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. 25

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. 15
Dingo packs live in large, stable territories and generally have only one fertile, which
limits their rate of increase.20 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. 18

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. 21

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 14-20
Reading Passage has eight sections, A-H.
Which sections contains the following information?
Write the correct letter, A-H, in boxes 14-20 on your answer sheet.
NB You may use any letter more than once.

14 a description of a barrier designed to stop dingoes, which also divides two kinds of
non-natives animals
15 how dingoes ensure that rival species do not dominate
16 a reference to a widespread non-native species that other animals feed on
17 a mention of the dingo’s arrival in Australia
18 research which has proved that dingoes have resorted to eating young livestock
19 a description of a method used to kill dingoes
20 the way that the structure of dingo groups affects how quickly their numbers grow

Questions 21-23
Look at the following statements (Questions 21-23) 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 21-23 on your answer sheet.

21 Dingoes tend to hunt native animals rather than hunting other non-
native predators.
22 The presence of dingoes puts the income of some people at risk.
23 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 24-26
Complete the sentences below.
Choose NO MORE THAN TWO WORDS from the passage for each answer.
Write your answers in boxes 24-26 on your answer sheet.
24 The dingo replaced the ………. as the main predatory animal in Australia.
25 Foxes and cats are more likely to hunt native animals when there are
fewer…………….
26 Australian animals reproduce at a slow rate as a natural way of avoiding …………….
 Pacific navigation and voyaging

How people migrated to the Pacific islands

The many tiny islands of the Pacific Ocean had no human population until ancestors
of today’s islanders sailed from Southeast Asia in ocean-going canoes approximately
2,000 years ago. At the present time, the debate continues about exactly how they
migrated such vast distances across the ocean, without any of the modern technologies
we take for granted.

Although the romantic vision of some early twentieth-century writers of fleets of

heroic navigators simultaneously setting sail had come to be considered by later
investigators to be exaggerated, no considered assessment of Pacific voyaging was
forthcoming until 1956 when the American historian Andrew Sharp published his
research. 28 Sharp challenged the ‘heroic vision’ by asserting that the expertise of the
navigators was limited, and that the settlement of the islands was not systematic, being
more dependent on good fortune by drifting canoes. 29 Sharp’s theory was widely
challenged, and deservedly so. If nothing else, however, it did spark renewed interest
in the topic and precipitated valuable new research. 30

Since the 1960s a wealth of investigations has been conducted, and most of them,
thankfully, have been of the ‘non-armchair’ variety. While it would be wrong to denigrate
all ‘armchair’ research - that based on an examination of available published materials -
it has turned out that so little progress had been made in the area of Pacific voyaging
because most writers relied on the same old sources - travelers’ journals or missionary
narratives compiled by unskilled observers. After Sharp, this began to change, and
researchers conducted most of their investigations not in libraries, but in the field.

In 1965, David Lewis, a physician and experienced yachtsman, set to work using his
own unique philosophy: he took the yacht he had owned for many years and navigated
through the islands in order to contact those men who still find their way at sea using
traditional methods. He then accompanied these men, in their traditional canoes, on test
voyages from which all modern instruments were banished from sight, though Lewis
secretly used them to confirm the navigator’s calculations. His most famous such
voyage was a return trip of around 1,000 nautical miles between two islands in mid-
ocean. Far from drifting, as proposed by Sharp, Lewis found that ancient navigators
would have known which course to steer by memorizing which stars rose and set
in certain positions along the horizon 33 and this gave them fixed directions by
which to steer their boats.

The geographer Edwin Doran followed a quite different approach. He was interested in
obtaining exact data on canoe sailing performance, and to that end employed the
latest electronic instrumentation. Doran traveled on board traditional sailing canoes
in some of the most remote parts of the Pacific, all the while using his instruments to
record canoe speeds in different wind strengths - from gales to calms - the angle
canoes could sail relative to the wind. In the process, he provided the first really precise
attributes of traditional sailing canoes.

A further contribution was made by Steven Horvath. As a physiologist, Horvath’s interest

was not in navigation techniques or in canoes, but in the physical capabilities of the men
themselves. By adapting standard physiological techniques, Horvath was able to
calculate the energy expenditure required to paddle canoes of this sort at times when
there was no wind to fill the sails, or when the wind was contrary. He concluded that
paddles, or perhaps long oars, could indeed have propelled for long distances what
were primarily sailing vessels.

Finally, a team led by p Wall Garrard conducted important research, in this case by
making investigations while remaining safely in the laboratory. Wall Garrard’s unusual
method was to use the findings of linguists who had studied the languages of the Pacific
islands, many of which are remarkably similar although the islands where they are
spoken are sometimes thousands of kilometres apart. Clever adaptation of computer
simulation techniques pioneered in other disciplines allowed him to
produce convincing models suggesting the migrations were indeed systematic, but not
simultaneous. Wall Garrard proposed the migrations should be seen not as a single
journey made by a massed fleet of canoes, but as a series of ever more ambitious
voyages, each pushing further into the unknown ocean.

What do we learn about Pacific navigation and voyaging from this research? Quite
correctly, none of the researchers tried to use their findings to prove one theory or
another; experiments such as these cannot categorically confirm or
negate a hypothesis. 37 The strength of this research lay in the range of
methodologies employed. 38 When we splice together these findings we can propose
that traditional navigators used a variety of canoe types, sources of water and
navigation techniques, and it was this adaptability which was their greatest
accomplishment. 39 These navigators observed the conditions prevailing at sea at the
time a voyage was made and altered their techniques accordingly. Furthermore, the
canoes of the navigators were not drifting helplessly at sea but were most likely part of a
systematic migration; as such, the Pacific peoples were able to view the ocean as an
avenue, not a barrier, to communication before any other race on Earth. Finally, one
unexpected but most welcome consequence of this research has been a renaissance in
the practice of traditional voyaging. In some groups of islands in the Pacific today young
people are resurrecting the skills of their ancestors, when a few decades ago it seemed
they would be lost forever.

They say I Say

Andrew Sharp --- lucky

Skills