The Hunted
Here in Australia
we have become a
There are now many animals living in Australia
that have been deliberately introduced to the wild. Some came by accident, others were escapees from aviaries, aquaria and
zoos. They were introduced for a number of reasons that now may sound quaint or
impractical. It is a good history lesson to examine past introductions so that
the same mistakes are not repeated in the future.
When populations of domestic animals such as livestock or
household pets become established in the wild they are called feral animals.
These include the feral cats, feral pigs, the hare, feral goats, and feral
horse or brumby. However, the introduced species that did not originate from
domestic livestock are referred to as exotics, exotic wild animals or
introduced wild animals. Here are some reasons why these wild animals from
other countries were introduced into Australia
and just a few example of the species involved:
Pigs
This Web Page is The hunted Australia
has been warned feral pests, such as the 20 million wild pigs in the country.
Domestic pigs were introduced to Australia
at the time of European settlement as a food source. Unfortunately many of these pigs were often
allowed to roam free. During the 19th
Century, many domestic pigs were transported to other settlements and due to
either insufficient enclosures or deliberate releases,
it was not long before feral populations of pigs became established.
Feral pigs are found from western Victoria,
through New South Wales into Queensland;
and across northern Australia,
from Cape York in the east to the Kimberley
region in the west (insert distribution map).
The principal factors affecting feral pig distribution are reliable
supplies of food, water and shelter. As
feral pigs need to drink daily in hot weather, they are not found in dry inland
areas of Australia
where there is no permanent surface water.
If conditions are favourable, feral pigs can breed
throughout the year. Usually one or two
litters are produced each year, with an average of six piglets being born.
Piglets become sexually mature when they are about six months old. Piglets are
however prone to a high mortality rate, depending on food supplies and weather
conditions. Sows (female pigs) will
aggressively protect their young from any threat.
Feral pigs are omnivores, which means
that they will eat both plant material and animals. Feral pigs will eat fruit,
roots, beetles, reptiles, crocodile eggs, young rabbits and other small animals
as well as scavenge on carrion. Grass makes up the bulk of their diet where
available
Natural ecosystems are damaged by feral pigs
. Their habit of wallowing and rooting around the edges of watercourses
and swamps destroys the vegetation that prevents erosion, and provides food and
nesting sites for native wildlife.
Because feral pigs have such varied eating habits, species such as
ground nesting birds are also vulnerable.
On Lord Howe Island, both the endemic woodhen and
the providence petrel have disappeared from areas where pigs are found.
Feral pigs are also a serious agricultural pest in Australia. They eat and damage crops and pasture, they
also damage fences. Feral pigs kill and
eat up to 40 percent of lambs born in some areas, costing the sheep industry
millions of dollars each year. The
greatest threat feral pigs pose to agriculture is their potential to carry
certain diseases such as foot and mouth disease and to act as hosts for the
screw worm fly should these be accidentally introduced.
There are a number of techniques available to control the
damage done by feral pigs. In open
country, mustering and shooting from helicopters can be effective in the
short-term. Pigs shot in the wild may be used for their meat if the appropriate
facilities are nearby. In 1990, Australia
exported in excess of 1500 tonnes of wild pig meat to European countries.
Poisoning is an effective control method. The most commonly used poison for feral pigs
is 1080 in grain. Traps, baited with
grain, are also used in an effort to control feral pigs. Traps are built near areas where pigs show
signs of activity, such as watering holes.
Landholders often leave traps permanently erected,
only activating the gate when pig signs become evident.
Feral pig populations can increase at 80 to 110% per annum,
depending on the area and seasonal conditions.
Consequently, control strategies need to be efficiently and effectively
applied to prevent population recovery after a control operation has been
executed.
Feral pigs are both an environmental and agricultural
pest. They can cause quite serious
damage to the environment with their habit of wallowing and rooting for
food. Feral pigs can also kill up to 40
percent of lambs in some areas of Australia. Unfortunately, because of the high
reproductive rate of feral pigs, they have the capacity to recover quickly from
control operations. Research is
continuing into techniques that will control the damage caused to the
environment and agriculture.
Foxes
The average fox
Cats Feral
I hate
cats
Rabbits / Hare
Yum Rabbits are one of Australia's
foremost environmental pests. They have been one of the main causes of habitat
destruction, native flora and fuana extinction, land
degradation and crop destruction. This site explores the history of the rabbit
and its impact on native Australian flora and fauna. Special emphasis is placed
on immunocontraception- a current research project in
biological rabbit control
Goats
Sorta
Buffalo
Deer
These
first wild deer in Australia
were seen as a great success and a further five species of deer from different
parts of the world were eventually established in the wild. They were fallow
deer, red deer, sambar, rusa deer, chital and hog deer. However, none of them have
become widely distributed. Each species has a different and fairly narrow set
of requirements so that they are now found in widely varying climatic regions
in small pockets of favourable habitat.
Only the sambar, found in the forested ranges of Victoria
through to south-eastern New South Wales,
could be regarded as having the potential to increase its range. However,
hunting appears to prevent this deer from becoming a pest. Consequently, no
species of deer is regarded as a serious pest and since their numbers are
limited by environmental factors such as climate, cover and food supply, they
are more likely to be viewed as a recreational resource. Farming deer for
venison and antler velvet is a growing industry with approximately 100 000 deer
on farms in Australia.
Camels
