Rabbits in Australia
Encyclopedia
In Australia
, rabbit
s are a serious mammal
ian pest and are an invasive species
. Annually, European rabbit
s cause millions of dollars of damage to crop
s.
Since their introduction from Europe in the 19th century, the effect of rabbits on the ecology of Australia
has been devastating. Rabbits are suspected of being the most significant known factor in species loss in Australia. The loss of plant species is unknown at this time. Rabbits often kill young trees in orchards, forests and on properties by ringbarking them.
Rabbits are also responsible for serious erosion
problems as they eat native plants, leaving the topsoil
exposed and vulnerable to sheet, gully and wind erosion. The removal of this topsoil is devastating to the land as it takes many hundreds of years to regenerate.
Rabbits were first introduced to Australia by the First Fleet
in 1788. They were bred as food animals, probably in cages. In the first decades they do not appear to have been numerous, judging from their absence from archaeological collections of early colonial food remains. However, by 1827 in Tasmania
a newspaper article noted ‘…the common rabbit is becoming so numerous throughout the colony, that they are running about on some large estates by thousands. We understand, that there are no rabbits whatever in the elder colony' [i.e. New South Wales]. This clearly shows that a localised rabbit population explosion was underway in Tasmania in the early 19th century. At the same time in NSW Cunningham noted that '... rabbits are bred around houses, but we have yet no wild ones in enclosures...’ He noted that the scrubby, sandy soil between Sydney and Botany Bay would be ideal for farming rabbits. Enclosures appears to mean more extensive rabbit-farming warrens, rather than cages. The first of these, in Sydney at least, was one built by Alexander Macleay
at Elizabeth Bay House
,'a preserve or rabbit-warren, surrounded by a substantial stone wall, and well stocked with that choice game'. In the 1840s rabbit-keeping became even more common, with examples of the theft of rabbits from ordinary peoples' houses appearing in court records, and rabbits entering the diet of ordinary people.
A question remains as to why there was no outbreak before the start of the current infestation. The localised Tasmanian rabbit plague was noted, but it would be surprising if there were no escapes from the many warrens and cages that would have been present throughout the area of European settlement in southeastern Australia. It is possible that native predators, particularly carnivorous dasyurids, were much more effective as natural controllers of the population than the later fox
es and feral cats. When their populations collapsed as a result of habitat destruction, and sometimes deliberate hunting, rabbit populations could rise with far less restraint.
The current infestation appears to have originated with the release of 12 wild rabbits by Thomas Austin
on his property, Barwon Park, near Winchelsea, Victoria
, in October 1859 for hunting
purposes. While living in England
, Austin had been an avid hunter, regularly dedicating his weekends to rabbit shooting. Upon arriving in Australia, which had no native rabbit population, Austin asked his nephew William Austin in England to send him 12 grey rabbits, five hares, 72 partridges and some sparrows so that he could continue his hobby in Australia by creating a local population of the species. However William could not source enough grey rabbits to meet his uncle's order. So he topped it up by buying domestic rabbits. One theory as to why the Barwon park rabbits adapted so well to Australia is that the hybrid rabbits that resulted from the interbreeding of the two distinct types were particularly hardy and vigorous. Many other farms released their rabbits into the wild after Austin. At the time he had stated, "The introduction of a few rabbits could do little harm and might provide a touch of home, in addition to a spot of hunting."
Rabbits are extremely prolific creatures, and spread rapidly across the southern parts of the country. Australia had ideal conditions for a rabbit population explosion. With mild winters, rabbits were able to breed the entire year. With widespread farming, areas that may have been scrub or woodlands were instead turned into vast areas with low vegetations, creating ideal habitat for rabbits.
In a classic example of unintended consequences
, within ten years of their introduction in 1859, rabbits had become so prevalent that two million could be shot or trapped annually without having any noticeable effect on the population. It was the fastest spread ever recorded of any mammal anywhere in the world. Today rabbits are entrenched in the southern and central areas of the country, with scattered populations in the northern deserts.
Although the rabbit is a notorious pest it proved helpful to many people during the Great Depression
and during wartime. Trapping rabbits helped farmers, stockmen and station
hands by providing something to eat, extra income and in some cases helped pay off farming debts. Rabbits were fed to working dogs, and boiled to be fed to the poultry. Later, frozen rabbit carcases were traded locally and exported. Pelts too, were used in the fur trade and are still used in the felt-hat industry
.
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A Royal Commission
was held to investigate the situation in 1901. Once the problem was understood, various control methods were tried to limit or reduce the population of rabbits in Australia. These methods had limited success until the introduction of biological control methods in the latter half of the 20th century.
Shooting rabbits is one of the most common control methods. However, this has little noticeable effect on rabbit populations.
Destroying warrens through ripping (a procedure where rabbits are dismembered or buried alive as a bulldozer dragging sharp tines is driven over their warrens/burrows), ploughing, blasting, and fumigating is widely used especially on large farms (known as 'stations'). The sandy soil in many parts of Australia makes ripping and ploughing a viable method of control, and both tractors and bulldozers are used for this operation.
Poison
ing is probably the most widely-used of the conventional techniques, as it requires the least effort. The disadvantage is that the rabbit cannot be used as food for either humans or pets afterward. Two commonly-used poisons for rabbit control are sodium fluoroacetate ("1080") and pindone
.
Another technique is hunting using ferret
s, where ferrets are deployed to chase the rabbits out to be shot or into nets set over the burrows. Since ferrets are limited in the number of rabbits they can kill, this is more a hunting activity than a serious control method.
Historically, trapping was also frequently used; steel-jawed leg-holding traps were banned in most states in the 1980s on animal cruelty grounds, though trapping continues at a lower level using rubber-jawed traps. All of these techniques are limited to working only in settled areas and are quite labour-intensive.
In 1907, the rabbit-proof fence
was built in Western Australia between Cape Keraudren and Esperance to try to control the rabbit population. European rabbits can both jump very high and burrow underground. Even assuming a perfectly intact fence stretching for hundreds of miles, and assuming that farmers or graziers do not leave gates open for livestock
or machinery, it was unlikely to be a success.
, Myxomatosis
was deliberately released into the rabbit population, causing it to drop from an estimated 600 million to around 100 million. Genetic resistance in the remaining rabbits allowed the population to recover to 200-300 million by 1991.
To combat this trend, Commonwealth Scientific and Industrial Research Organisation (CSIRO)
comprehensively tested over three years from June 1991 calicivirus
(also known as Rabbit Haemorrhagic Disease or RHD). The virus accidentally escaped from a quarantine compound on Wardang Island, South Australia where field tests were being carried out on the potential of the virus for biological control of wild rabbits, and by late October 1995 it was recorded in rabbits at Yunta and Gum Creek, in north eastern South Australia. By the winter of 1996, the virus was established in Victoria, New South Wales, the Northern Territory and Western Australia. The success of the virus was found to be higher in extreme heat. This was because it appears there is another calicivirus in the colder, wetter areas of Australia, and that this virus was immunising rabbits against the more virulent form.
A legal vaccine exists in Australia for RHD. There is no cure for either Myxomatosis or RHD, and many affected pets are euthanised. In Europe, where rabbits are farmed on a large scale, they are protected against myxomatosis and calicivirus with a genetically modified virus. The vaccine was developed in Spain.
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...
s are a serious mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
ian pest and are an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
. Annually, European rabbit
European Rabbit
The European Rabbit or Common Rabbit is a species of rabbit native to south west Europe and north west Africa . It has been widely introduced elsewhere often with devastating effects on local biodiversity...
s cause millions of dollars of damage to crop
Crop
Crop may refer to:* Crop, a plant grown and harvested for agricultural use* Crop , part of the alimentary tract of some animals* Crop , a modified whip used in horseback riding or disciplining humans...
s.
Effects on Australia's ecology
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
has been devastating. Rabbits are suspected of being the most significant known factor in species loss in Australia. The loss of plant species is unknown at this time. Rabbits often kill young trees in orchards, forests and on properties by ringbarking them.
Rabbits are also responsible for serious erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
problems as they eat native plants, leaving the topsoil
Topsoil
Topsoil is the upper, outermost layer of soil, usually the top to . It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs.-Importance:...
exposed and vulnerable to sheet, gully and wind erosion. The removal of this topsoil is devastating to the land as it takes many hundreds of years to regenerate.
Rabbits were first introduced to Australia by the First Fleet
First Fleet
The First Fleet is the name given to the eleven ships which sailed from Great Britain on 13 May 1787 with about 1,487 people, including 778 convicts , to establish the first European colony in Australia, in the region which Captain Cook had named New South Wales. The fleet was led by Captain ...
in 1788. They were bred as food animals, probably in cages. In the first decades they do not appear to have been numerous, judging from their absence from archaeological collections of early colonial food remains. However, by 1827 in Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
a newspaper article noted ‘…the common rabbit is becoming so numerous throughout the colony, that they are running about on some large estates by thousands. We understand, that there are no rabbits whatever in the elder colony' [i.e. New South Wales]. This clearly shows that a localised rabbit population explosion was underway in Tasmania in the early 19th century. At the same time in NSW Cunningham noted that '... rabbits are bred around houses, but we have yet no wild ones in enclosures...’ He noted that the scrubby, sandy soil between Sydney and Botany Bay would be ideal for farming rabbits. Enclosures appears to mean more extensive rabbit-farming warrens, rather than cages. The first of these, in Sydney at least, was one built by Alexander Macleay
Alexander Macleay
Hon. Alexander Macleay MLC FLS FRS was a leading member of the Linnean Society and a fellow of the Royal Society.Macleay was born on Ross-shire, Scotland, eldest son of William Macleay, provost of Wick...
at Elizabeth Bay House
Elizabeth Bay House
Elizabeth Bay House is a historic home in the suburb of Elizabeth Bay in Sydney, New South Wales, Australia. Built between 1835 and 1839, Elizabeth Bay House was known as 'the finest house in the colony'. Elizabeth Bay House is a home in the Regency style, originally surrounded by a garden, but...
,'a preserve or rabbit-warren, surrounded by a substantial stone wall, and well stocked with that choice game'. In the 1840s rabbit-keeping became even more common, with examples of the theft of rabbits from ordinary peoples' houses appearing in court records, and rabbits entering the diet of ordinary people.
A question remains as to why there was no outbreak before the start of the current infestation. The localised Tasmanian rabbit plague was noted, but it would be surprising if there were no escapes from the many warrens and cages that would have been present throughout the area of European settlement in southeastern Australia. It is possible that native predators, particularly carnivorous dasyurids, were much more effective as natural controllers of the population than the later fox
Fox
Fox is a common name for many species of omnivorous mammals belonging to the Canidae family. Foxes are small to medium-sized canids , characterized by possessing a long narrow snout, and a bushy tail .Members of about 37 species are referred to as foxes, of which only 12 species actually belong to...
es and feral cats. When their populations collapsed as a result of habitat destruction, and sometimes deliberate hunting, rabbit populations could rise with far less restraint.
The current infestation appears to have originated with the release of 12 wild rabbits by Thomas Austin
Thomas Austin
Thomas Austin was an English settler in Australia who is generally credited with the introduction of rabbits into Australia in 1859.- Personal life :...
on his property, Barwon Park, near Winchelsea, Victoria
Winchelsea, Victoria
Winchelsea is a town in Victoria, Australia. It is in the Surf Coast Shire local government area and located on the Barwon River 115 km south-west of Melbourne and close to Geelong .- History :...
, in October 1859 for hunting
Hunting
Hunting is the practice of pursuing any living thing, usually wildlife, for food, recreation, or trade. In present-day use, the term refers to lawful hunting, as distinguished from poaching, which is the killing, trapping or capture of the hunted species contrary to applicable law...
purposes. While living in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, Austin had been an avid hunter, regularly dedicating his weekends to rabbit shooting. Upon arriving in Australia, which had no native rabbit population, Austin asked his nephew William Austin in England to send him 12 grey rabbits, five hares, 72 partridges and some sparrows so that he could continue his hobby in Australia by creating a local population of the species. However William could not source enough grey rabbits to meet his uncle's order. So he topped it up by buying domestic rabbits. One theory as to why the Barwon park rabbits adapted so well to Australia is that the hybrid rabbits that resulted from the interbreeding of the two distinct types were particularly hardy and vigorous. Many other farms released their rabbits into the wild after Austin. At the time he had stated, "The introduction of a few rabbits could do little harm and might provide a touch of home, in addition to a spot of hunting."
Rabbits are extremely prolific creatures, and spread rapidly across the southern parts of the country. Australia had ideal conditions for a rabbit population explosion. With mild winters, rabbits were able to breed the entire year. With widespread farming, areas that may have been scrub or woodlands were instead turned into vast areas with low vegetations, creating ideal habitat for rabbits.
In a classic example of unintended consequences
Unintended Consequences
Unintended Consequences is a novel by John Ross, first published in 1996 by Accurate Press. The story chronicles the history of the gun culture, gun rights and gun control in the United States from the early 1900s through the late 1990s...
, within ten years of their introduction in 1859, rabbits had become so prevalent that two million could be shot or trapped annually without having any noticeable effect on the population. It was the fastest spread ever recorded of any mammal anywhere in the world. Today rabbits are entrenched in the southern and central areas of the country, with scattered populations in the northern deserts.
Although the rabbit is a notorious pest it proved helpful to many people during the Great Depression
Great Depression
The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...
and during wartime. Trapping rabbits helped farmers, stockmen and station
Station (Australian agriculture)
Station is the term for a large Australian landholding used for livestock production. It corresponds to the North American term ranch or South American estancia...
hands by providing something to eat, extra income and in some cases helped pay off farming debts. Rabbits were fed to working dogs, and boiled to be fed to the poultry. Later, frozen rabbit carcases were traded locally and exported. Pelts too, were used in the fur trade and are still used in the felt-hat industry
Akubra
Akubra is an Australian brand of bush hat, whose wide-brimmed styles are a distinctive part of Australian culture, especially in rural areas. The name is believed to be derived from an Aboriginal word for head covering....
.
Control measures
Royal Commission
In Commonwealth realms and other monarchies a Royal Commission is a major ad-hoc formal public inquiry into a defined issue. They have been held in various countries such as the United Kingdom, Australia, Canada, New Zealand, and Saudi Arabia...
was held to investigate the situation in 1901. Once the problem was understood, various control methods were tried to limit or reduce the population of rabbits in Australia. These methods had limited success until the introduction of biological control methods in the latter half of the 20th century.
Conventional control measures
Destroying warrens through ripping (a procedure where rabbits are dismembered or buried alive as a bulldozer dragging sharp tines is driven over their warrens/burrows), ploughing, blasting, and fumigating is widely used especially on large farms (known as 'stations'). The sandy soil in many parts of Australia makes ripping and ploughing a viable method of control, and both tractors and bulldozers are used for this operation.
Poison
Poison
In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....
ing is probably the most widely-used of the conventional techniques, as it requires the least effort. The disadvantage is that the rabbit cannot be used as food for either humans or pets afterward. Two commonly-used poisons for rabbit control are sodium fluoroacetate ("1080") and pindone
Pindone
Pindone is an anticoagulant drug for agricultural use. It is commonly used as a rodenticide in the management of rat and rabbit populations.It is pharmacologically analogous to warfarin and inhibits the synthesis of Vitamin K-dependent clotting factors....
.
Another technique is hunting using ferret
Ferret
The ferret is a domesticated mammal of the type Mustela putorius furo. Ferrets are sexually dimorphic predators with males being substantially larger than females. They typically have brown, black, white, or mixed fur...
s, where ferrets are deployed to chase the rabbits out to be shot or into nets set over the burrows. Since ferrets are limited in the number of rabbits they can kill, this is more a hunting activity than a serious control method.
Historically, trapping was also frequently used; steel-jawed leg-holding traps were banned in most states in the 1980s on animal cruelty grounds, though trapping continues at a lower level using rubber-jawed traps. All of these techniques are limited to working only in settled areas and are quite labour-intensive.
Rabbit-proof fence
The State Barrier Fence of Western Australia, formerly known as the No. 1 Rabbit-proof Fence, the State Vermin Fence and the Emu Fence, is a pest-exclusion fence constructed between 1901 and 1907 to keep rabbits and other agricultural pests, from the east, out of Western Australian pastoral...
was built in Western Australia between Cape Keraudren and Esperance to try to control the rabbit population. European rabbits can both jump very high and burrow underground. Even assuming a perfectly intact fence stretching for hundreds of miles, and assuming that farmers or graziers do not leave gates open for livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
or machinery, it was unlikely to be a success.
Biological measures
Releasing rabbit-borne diseases has proven somewhat successful in controlling the population of rabbits in Australia. In 1950, after research carried out by Frank FennerFrank Fenner
Frank John Fenner, AC, CMG, MBE, FRS, FAA was an Australian scientist with a distinguished career in the field of virology...
, Myxomatosis
Myxomatosis
Myxomatosis is a disease that affects rabbits and is caused by the Myxoma virus. It was first observed in Uruguay in laboratory rabbits in the late 19th century. It was introduced into Australia in 1950 in an attempt to control the rabbit population...
was deliberately released into the rabbit population, causing it to drop from an estimated 600 million to around 100 million. Genetic resistance in the remaining rabbits allowed the population to recover to 200-300 million by 1991.
To combat this trend, Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Commonwealth Scientific and Industrial Research Organisation
The Commonwealth Scientific and Industrial Research Organisation is the national government body for scientific research in Australia...
comprehensively tested over three years from June 1991 calicivirus
Rabbit haemorrhagic disease
Rabbit haemorrhagic disease , also known as rabbit calicivirus disease or viral haemorrhagic disease , is a highly infectious and often fatal disease that affects wild and domestic rabbits of the species Oryctolagus cuniculus...
(also known as Rabbit Haemorrhagic Disease or RHD). The virus accidentally escaped from a quarantine compound on Wardang Island, South Australia where field tests were being carried out on the potential of the virus for biological control of wild rabbits, and by late October 1995 it was recorded in rabbits at Yunta and Gum Creek, in north eastern South Australia. By the winter of 1996, the virus was established in Victoria, New South Wales, the Northern Territory and Western Australia. The success of the virus was found to be higher in extreme heat. This was because it appears there is another calicivirus in the colder, wetter areas of Australia, and that this virus was immunising rabbits against the more virulent form.
A legal vaccine exists in Australia for RHD. There is no cure for either Myxomatosis or RHD, and many affected pets are euthanised. In Europe, where rabbits are farmed on a large scale, they are protected against myxomatosis and calicivirus with a genetically modified virus. The vaccine was developed in Spain.
External links
- Dr Brian Cooke from CSIRO Wildlife and Ecology receiving the 2000 POL Eureka Prize for Environmental Research, for his lifetime commitment to reducing the devastation caused by rabbits on the Australian environment
- Australian Broadcasting Corporation Landline
- Australian Broadcasting Corporation Rabbiting On - Australian stories of experiences with the pest
- CSIRO Protection for Pet rabbits
- Culture Victoria – Nox All Rabbits video about rabbits and rabbit control in Australia