Review of the management of feral animals and their impact on ...

<strong>animals</strong> that can break through most farm fences, making it harder for graziers to
manage overgrazing by stock (Fisher et al. 2004).
Depleting <strong>and</strong> despoiling water supplies
Camels despoil water sources in <strong>the</strong> desert. Robinson et al. (2003), writing recently
about <strong>the</strong> Anangu Pitjantjatjara L<strong>and</strong>s in north-western South Australia, note:
‘…Camels are … having an increasing <strong>impact</strong> on desert water supplies. Not
only do <strong>the</strong>y drink large volumes <strong>of</strong> this valuable resource, <strong>the</strong>y also foul rock
holes <strong>and</strong> waterholes when <strong>the</strong>y get stuck <strong>and</strong> die. They also contribute to
increased rates <strong>of</strong> siltation in <strong>the</strong>se catchments.’
They conclude that:
‘many water supplies at rock holes <strong>and</strong> waterholes are now severely
compromised by <strong>the</strong> large volumes <strong>of</strong> water being consumed by an increasing
<strong>feral</strong> camel population <strong>and</strong> by a decreasing capacity <strong>of</strong> many rock-holes to
hold water due to ongoing siltation (frequently accelerated by camel activity).’
Camels are causing severe degradation to Dragon Tree Soak in Western Australia
(Peter Mason pers. comm.), identified by Morton et al. (1995) as a significant refuge
for biological diversity within <strong>the</strong> Great S<strong>and</strong>y Desert.
A camel can drink 200 litres in three minutes. Camels groups range from two to 45
individuals, averaging 11 per group (Dörges & Heucke 1995). A large group <strong>of</strong> thirsty
camels can drain a rocky waterhole, leaving nothing behind for kangaroos, emus <strong>and</strong>
pigeons (P. Copley pers. comm.). Where <strong>the</strong>y do not drain a waterhole <strong>the</strong>y can leave
it unfit for o<strong>the</strong>r <strong>animals</strong>. Peter Kendrick (pers. comm.) has seen rock holes in <strong>the</strong>
Rudall River National Park, Western Australia, up to 50 metres across, bubbling with
eutrophication from camel urine <strong>and</strong> excrement.
Peter Copley (pers. comm.) speculates that camels, by depleting water supplies, could
have contributed to <strong>the</strong> decline in South Australia (Garnett & Crowley 2000), <strong>of</strong> <strong>the</strong>
rare princess parrot. The uncommon scarlet-chested parrot <strong>and</strong> Major Mitchell’s
cockatoo may also be suffering from camels depleting water supplies (Robinson et al.
2003).
3.7.13 Swamp Buffalo (Bubalis bubalis)
O<strong>the</strong>r name
Water Buffalo
Summary
A large <strong>feral</strong> pest that causes massive habitat disturbance. Populations were greatly
reduced in <strong>the</strong> past but are now multiplying <strong>and</strong> spreading, especially on Aboriginal
l<strong>and</strong>s, <strong>and</strong> this is a serious cause for concern.
Distribution
Swamp buffalo occupy <strong>the</strong> Top End <strong>of</strong> <strong>the</strong> Nor<strong>the</strong>rn Territory, where <strong>the</strong>y are mainly
confined to floodplains with permanent water because <strong>of</strong> <strong>the</strong>ir need to drink regularly
<strong>and</strong> to wallow or ba<strong>the</strong> on hot days. They can reach densities as high as 34 per square
kilometre (Skeat et al. 1996). Bulls sometimes w<strong>and</strong>er as far east as <strong>the</strong> Townsville
area in Queensl<strong>and</strong>, as far west as Broome in Western Australia, <strong>and</strong> as far south as
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