Backbencher
Weblog for HIST 381 at NDSUWednesday, February 27, 2008
Research Paper: A brief discussion on the impacts of the introduction of the European rabbit (Oryctolagus cuniculus) in Australia
"The introduction of a few rabbits could do little harm and might provide a touch of home, in addition to a spot of hunting." Thomas Austin (10). This mentality helped introduce the worst vertebrate pest in Australian history. Here I will briefly discuss the significance of the European rabbit (Oryctolagus cuniculus) on the environment in Australia.
The first European rabbits landed in Australia with the First Fleet in 1788 (2,3). Over the years there were a number of other introductions of rabbits to the land. It is believed that most current rabbits descend from 13 (3) or 24 rabbits released by Thomas Austin of the Victorian Acclimatization Society in 1859 near Greelog (4, 7). At the time, people didn't really think about exotic species as a problem. Unfortunately the European rabbits got a foot hold in the environment and subsequently turned into an invasive species that dominates the land (6).
Rabbits are very hardy creatures and "breed like rabbits!" Many species can start to breed around 3 months of age and can produce dozens of kits each year. In Australia they flourished because of a lack of natural predators and other checks that usually keep rabbit populations manageable. This was a major factor in the rabbits as becoming invasive species (6).
Most rabbits live in community burrows or warrens that disrupt native vegetation and support weedy or undesirable plants. Rabbits live a semi-fossorial life style and dig up the soil in order to construct the warrens. This leads to high clay percentage or soil and increased pH levels on the mounds versus untouched land. These factors help increase erodibiltiy of the soil resulting in a loss of nutrients and poorer quality of the soil. The lower quality soils are mainly characterized by exotic plants whereas the untouched areas are dominated by native species (1).
The European rabbits have been blamed for having direct and indirect impacts on a number of native birds and mammals. The wombat population has declined likely due to food competition with rabbits. The wombats have to change their grazing habits. The adults can cope, but their young don't cope as well to the change. The bilby has been pushed into a few isolated areas. It only takes the rabbits around 10 years after colonizing an area to push out the bilbys (9). The Gould's petrels that nests on Cabbage Tree Island, NSW, populations dwindled because of rabbits reducing cover vegetation, exposing nesting sites, and exposing the bird-lime tree that traps birds (5).
The rabbits were not the only species brought over from Europe. Predators of the rabbits were also brought over such as the European red fox in 1868 (4, 9). Unfortunately the native species were naïve and foxes found them tasty and easy to catch. The population of red foxes was not only supported by the rabbits but the new prey as well. This has had detrimental effects to the populations of many native species.
It is estimated that the rabbits cause over $600 million (Australian) dollars of damage to agriculture every year and can impact the economy. That amount doesn't include the effects to native species, landscape, or future problems (4). The over browsing of vegetation and composition changes of the soil and flora has negatively affected pastoral productivity especially in arid and semi-arid areas (2). They have been declared pests by the Agriculture and Related Resources Protection Act of 1976 in Western Australia (7, 8). The cattle and sheep markets are a major part of the Australian economy. The cost of loss in production in the wool industry alone is over $115 million annually (9). It takes only 10-16 rabbits to eat what one sheep can consume (4). In some cases the rabbits will graze vegetation to the roots destroying the plant. The sheep and cattle normally won’t eat the roots (9).
By the late nineteenth century, people recognized the rabbits were becoming a problem. One of the first efforts to stop the rabbits was a rabbit proof fence that was completed in 1907 and spans 2,023 miles (10). The fence is by no means fool-proof, but it has some other positive effects. It is a firebreak and also keeps other unwanted animals away from farmers' lands. Without the fence, the monetary damage to crops and pastures would be a whole lot worse.
Australians have tried many different ways to exterminate or control the European rabbit population. Biocontrol agents such as myxomatosis in the 1950s, European rabbit flea, and rabbit calicivirus (RCD, RHD, or RHDV) have been employed with some success but the rabbits are still around (3, 5, 7). A few other ways of controlling include a viral-vectored immunocontraception (VVIC), bait with a brodifacoum anticoagulant, traps, poisons (pindone, 1080), and by destroying warrens (5, 1, 2).
I think it's safe to say that Thomas Austin and the Victorian Acclimatization Society had no idea of what the future impacts on the environment would be after releasing the rabbits in Australia. One would hope that we all could learn from past mistakes, but for some reason that doesn't always happen. Releasing a non-native or exotic species (even biocontrol agents) to an environment for any reason should be taken with great consideration and not hastily. One of the viruses might have worked and wiped out the entire population of rabbits if there had been a perfectly executed plan. Another example of poor judgment was the introduction of cane toads (Bufo marinus) to eat bugs destroying the sugarcane crop. The life habits (especially the excessive breeding of the toads) of the toad and beetles could have been studied more extensively and they would have found if they were incompatible before it was too late. Now areas are overrun with toads.
Exotic species can be defined as "species that occur outside their natural ranges because of human activity (6)." These species are not just a problem in Australia, but all over the world. As long as humans keep colonizing areas, we're going to intentionally or unintentionally bring new species with us. The best we can do is to try and learn from our mistakes and try to minimize negative impacts to the environment. At least Australians found a market for rabbit fur and canned rabbit meat. Unfortunately the market isn't worth hundreds of millions of dollars to offset the damage done by the European rabbits.
1. Eldridge, D.J., Myers, C.A., 2001. The impact of warrens of the European rabbit (Oryctolagus cuniculus L.) on soil and ecological processes in a semi-arid Australian woodland. Journal of Arid Environment 47, 325-337.
2. Eldridge, D.J., Simpsom, R. 2002. Rabbit (Oryctolagus cuniculus L.) impacts on vegetation and soils, and implications for management of wooded rangelands. Basic and Applied Ecology 3, 19-29.
3. Hayes, R. A., Richardson, B.J., 2001. Biological control of the rabbit in Australia: lessons not learned? TRENDS in Microbiology 9, 459-460.
4. Hinds, L.A., Cooke, B.D., Robinson, T.J., Williams, C.K. Paper prepared for Prime Minister’s Science and Engineering Council, Sept. 1996. Rabbits – prospects for long term control: mortality and fertility control.
5. Priddel, D., Carlile, N., Wheeler, R. 2000. Eradication of European rabbits (Oryctolagus cuniculus) from Cabbage Tree Island, NSW, Australia, to protect the breeding habitat of Gould’s petrel (Pterodroma leucoptera leucoptera). Biological Conservation 94, 115-125.
6. Primack, R.B. A Primer of Conservation Biology. Sinauer Associates, Inc.; Publishers Sunderland, Massachusetts, 2004.
7. Department of Agriculture. Staff of the Vertebrate Pest Research Section. 2003. Farmnote: European rabbit. www.agric.wa.goc.au accessed 1/30/08
8. Department of Agriculture. Lowe, T. and Twigg, L. 2007. Rabbit control in urban and semi-urban areas. www.agric.wa.goc.au 1/30/08
9. Australia's Commonwealth Scientific and Industrial Research Organization. 1997. Environmental damage by wild rabbits: eating the heart out of the country. www.csiro.au/communication/rabbits/qa2.htm accessed 2/2/08
10. Agriculture Protection Board. 2001. The State Barrier Fence of Western Australia Centenary 1901-2001 http://www.agric.wa.gov.au/content/pw/vp/barrier_intro_history.pdf accessed 2/20/08
The first European rabbits landed in Australia with the First Fleet in 1788 (2,3). Over the years there were a number of other introductions of rabbits to the land. It is believed that most current rabbits descend from 13 (3) or 24 rabbits released by Thomas Austin of the Victorian Acclimatization Society in 1859 near Greelog (4, 7). At the time, people didn't really think about exotic species as a problem. Unfortunately the European rabbits got a foot hold in the environment and subsequently turned into an invasive species that dominates the land (6).
Rabbits are very hardy creatures and "breed like rabbits!" Many species can start to breed around 3 months of age and can produce dozens of kits each year. In Australia they flourished because of a lack of natural predators and other checks that usually keep rabbit populations manageable. This was a major factor in the rabbits as becoming invasive species (6).
Most rabbits live in community burrows or warrens that disrupt native vegetation and support weedy or undesirable plants. Rabbits live a semi-fossorial life style and dig up the soil in order to construct the warrens. This leads to high clay percentage or soil and increased pH levels on the mounds versus untouched land. These factors help increase erodibiltiy of the soil resulting in a loss of nutrients and poorer quality of the soil. The lower quality soils are mainly characterized by exotic plants whereas the untouched areas are dominated by native species (1).
The European rabbits have been blamed for having direct and indirect impacts on a number of native birds and mammals. The wombat population has declined likely due to food competition with rabbits. The wombats have to change their grazing habits. The adults can cope, but their young don't cope as well to the change. The bilby has been pushed into a few isolated areas. It only takes the rabbits around 10 years after colonizing an area to push out the bilbys (9). The Gould's petrels that nests on Cabbage Tree Island, NSW, populations dwindled because of rabbits reducing cover vegetation, exposing nesting sites, and exposing the bird-lime tree that traps birds (5).
The rabbits were not the only species brought over from Europe. Predators of the rabbits were also brought over such as the European red fox in 1868 (4, 9). Unfortunately the native species were naïve and foxes found them tasty and easy to catch. The population of red foxes was not only supported by the rabbits but the new prey as well. This has had detrimental effects to the populations of many native species.
It is estimated that the rabbits cause over $600 million (Australian) dollars of damage to agriculture every year and can impact the economy. That amount doesn't include the effects to native species, landscape, or future problems (4). The over browsing of vegetation and composition changes of the soil and flora has negatively affected pastoral productivity especially in arid and semi-arid areas (2). They have been declared pests by the Agriculture and Related Resources Protection Act of 1976 in Western Australia (7, 8). The cattle and sheep markets are a major part of the Australian economy. The cost of loss in production in the wool industry alone is over $115 million annually (9). It takes only 10-16 rabbits to eat what one sheep can consume (4). In some cases the rabbits will graze vegetation to the roots destroying the plant. The sheep and cattle normally won’t eat the roots (9).
By the late nineteenth century, people recognized the rabbits were becoming a problem. One of the first efforts to stop the rabbits was a rabbit proof fence that was completed in 1907 and spans 2,023 miles (10). The fence is by no means fool-proof, but it has some other positive effects. It is a firebreak and also keeps other unwanted animals away from farmers' lands. Without the fence, the monetary damage to crops and pastures would be a whole lot worse.
Australians have tried many different ways to exterminate or control the European rabbit population. Biocontrol agents such as myxomatosis in the 1950s, European rabbit flea, and rabbit calicivirus (RCD, RHD, or RHDV) have been employed with some success but the rabbits are still around (3, 5, 7). A few other ways of controlling include a viral-vectored immunocontraception (VVIC), bait with a brodifacoum anticoagulant, traps, poisons (pindone, 1080), and by destroying warrens (5, 1, 2).
I think it's safe to say that Thomas Austin and the Victorian Acclimatization Society had no idea of what the future impacts on the environment would be after releasing the rabbits in Australia. One would hope that we all could learn from past mistakes, but for some reason that doesn't always happen. Releasing a non-native or exotic species (even biocontrol agents) to an environment for any reason should be taken with great consideration and not hastily. One of the viruses might have worked and wiped out the entire population of rabbits if there had been a perfectly executed plan. Another example of poor judgment was the introduction of cane toads (Bufo marinus) to eat bugs destroying the sugarcane crop. The life habits (especially the excessive breeding of the toads) of the toad and beetles could have been studied more extensively and they would have found if they were incompatible before it was too late. Now areas are overrun with toads.
Exotic species can be defined as "species that occur outside their natural ranges because of human activity (6)." These species are not just a problem in Australia, but all over the world. As long as humans keep colonizing areas, we're going to intentionally or unintentionally bring new species with us. The best we can do is to try and learn from our mistakes and try to minimize negative impacts to the environment. At least Australians found a market for rabbit fur and canned rabbit meat. Unfortunately the market isn't worth hundreds of millions of dollars to offset the damage done by the European rabbits.
1. Eldridge, D.J., Myers, C.A., 2001. The impact of warrens of the European rabbit (Oryctolagus cuniculus L.) on soil and ecological processes in a semi-arid Australian woodland. Journal of Arid Environment 47, 325-337.
2. Eldridge, D.J., Simpsom, R. 2002. Rabbit (Oryctolagus cuniculus L.) impacts on vegetation and soils, and implications for management of wooded rangelands. Basic and Applied Ecology 3, 19-29.
3. Hayes, R. A., Richardson, B.J., 2001. Biological control of the rabbit in Australia: lessons not learned? TRENDS in Microbiology 9, 459-460.
4. Hinds, L.A., Cooke, B.D., Robinson, T.J., Williams, C.K. Paper prepared for Prime Minister’s Science and Engineering Council, Sept. 1996. Rabbits – prospects for long term control: mortality and fertility control.
5. Priddel, D., Carlile, N., Wheeler, R. 2000. Eradication of European rabbits (Oryctolagus cuniculus) from Cabbage Tree Island, NSW, Australia, to protect the breeding habitat of Gould’s petrel (Pterodroma leucoptera leucoptera). Biological Conservation 94, 115-125.
6. Primack, R.B. A Primer of Conservation Biology. Sinauer Associates, Inc.; Publishers Sunderland, Massachusetts, 2004.
7. Department of Agriculture. Staff of the Vertebrate Pest Research Section. 2003. Farmnote: European rabbit. www.agric.wa.goc.au accessed 1/30/08
8. Department of Agriculture. Lowe, T. and Twigg, L. 2007. Rabbit control in urban and semi-urban areas. www.agric.wa.goc.au 1/30/08
9. Australia's Commonwealth Scientific and Industrial Research Organization. 1997. Environmental damage by wild rabbits: eating the heart out of the country. www.csiro.au/communication/rabbits/qa2.htm accessed 2/2/08
10. Agriculture Protection Board. 2001. The State Barrier Fence of Western Australia Centenary 1901-2001 http://www.agric.wa.gov.au/content/pw/vp/barrier_intro_history.pdf accessed 2/20/08
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