Rabbits are by far one of the cutest and most cuddly animals around. But did you know that in Australia, wild rabbits are a serious pest! They cause millions of dollars of damage to crops. Since the 20th century, various methods have been employed to control the widespread population of rabbits in Australia.
Conventional methods include shooting rabbits and destroying their warrens. However, these only had limited success. In 1907, a rabbit-proof fence was built in Western Australia. This also proved to be an unsuccessful attempt to control the rabbit population.
The Origin and Growth
Rabbits were first introduced in Australia in 1788. They are said to have been bred as food animals, probably in cages. Although initially it has been observed that their population growth was not as rapid, by 1827 in Tasmania, a newspaper article reported that the population had become so widespread that they were running around everywhere. Given that there were no rabbits in New South Wales, it seems the rabbit population was rather localized and specific to Tasmania.
By the 1840s, rabbits became quite common and their population remained stable until around 1866. Their population went out of control around 1867. This was probably because of the disappearance of native predators and also because of the emergence of a sturdier breed of rabbits by natural selection.
The population growth of rabbits is said to be the fastest spread recorded of any animal in the world!
The Small Positive
Although the rabbit was regarded as a notorious pest, it did prove to be useful during the depressions of the 1890s and 1930s and also during wartime. Trapping rabbits helped farmers, stockmen, and stationhands by providing food and an extra income. In some cases, rabbits were also used to help pay off farming debts.
Rabbits were also fed to working dogs and boiled to be fed to poultry. Later on, frozen rabbit carcasses were traded locally and were also exported. Pelts were used in the fur trade and are still used the felt-hat industry.
The Effect
Since their introduction, the effects of rabbits on the ecology of Australia has been devastating. It is hard to imagine how an animal such as the rabbit can become such a nuisance and problem but that is how it is. Rabbis are suspected of being the most significant factor in species loss in Australia.
Rabbits are also responsible for serious erosion problems This is because they eat native plants. As a result, the topsoil is exposed and is vulnerable to different types of erosion. Also, the removal of topsoil is also a problem in the sense that it takes many hundreds of years to regenerate.
Biological Control Measures
Out of the many measures taken to control the population of wild rabbits, biological measures were one of the prominent and successful ones. From releasing rabbit-borne diseases (which proved somewhat successful in the beginning) to chicken cholera a lot of things were tried. In 1950, myxoma virus was released into the rabbit population, causing it to decrease rapidly. The population went from 600 million to 100 million! Genetic resistance in the remaining rabbits allowed the population to recover to 200-300 million by 1991.
The release of the calicivirus (causing rabbit hemorrhagic disease) proved to be a huge success.
The Concern
In 2017, a deadly virus was released by the Australian authorities to wipe out its wild rabbit populations. This virus is said to be both extremely lethal and highly contagious. In southern Europe, the scarcity of rabbits threatens the predator species higher up the food chain that are endangered and depend on small game such as rabbits. These include Iberian Lynx and the Iberian Imperial Eagle.
For this very reason, conservation experts are extremely concerned about this biological warfare in Australia. Such viruses pose a serious problem, particularly in areas where the preservation of a viable rabbit population is problematic.
