The introduction of pest species to Australia has largely, and regrettably, been extremely “successful”. The incredible rate of spread, and success of establishment, of pest species has been a major contributory to Australia’s infamous title for harbouring almost half of the world’s mammal extinctions over the past 200 years2.
Arguably, one of Australia’s worst introduced pests is the European rabbit (Oryctolagus cuniculus).
But could something so little and cute really be that much of a problem? Well, from my work experience with ACT Parks, Conservation and Lands, I have definitely come to the realization that yes – they definitely are a very big and ugly problem!
Rabbits grazing and burrowing habits can cause serious erosion, reduce survival and regeneration rates of native plants, create competition for food against native species, and altogether alter their habitats. What’s more, the damages brought about via economical losses in agriculture due to rabbits overgrazing is estimated at $115-250 million per year2,7.
Rabbits were originally released in Australia in the mid 1800s to sustain the sport of hunting3,5. By the early 1900s they had spread throughout much of the Australian continent (Figure 2).
Broad scale attempts to control rabbits from rabbit-proof fencing were said to be too late to make any difference. Biological control, such as the Myxoma virus, showed more promise, but eventual population immunity meant total eradication of rabbits was not possible5. Successful control measures have occurred on smaller scales though, such as Macquarie Island, where a program of aerial baiting and dogs were used to track down rabbits from July 20116. The project was a momentous success, no rabbits have been reported since November 2011 and the island is once again a thriving Antarctic ecosystem1,4 .
Aiming for a similar success is the rabbit eradication program at Mulligans Flat Nature Reserve, which is protecting the critically endangered box-gum grassy woodland residing there. The rabbits are causing harm to native vegetation regeneration and creating competition for habitat from the important reintroduced species and ecosystem engineer, the bettong. As baiting is not an option due to the danger presented to bettongs, the rangers of ACT Parks are actively managing the rabbits through night-time shootings and burrow gassing. I was fortunate enough to see this active management first hand on my work experience. This involved searching for rabbit burrows and warrens, then gassing and fumigating them with phosphine (Figure 4).
In the small area treated for this trial no rabbits were recorded during night-time spot-lighting approximately a week later, and only one burrow had shown an attempt at re-entry. This is a very promising result, and shows positive signs for intensive management that will hopefully see future eradication of rabbits within the Mulligans Flat Nature Reserve boundaries, and set the standard for pest management within Australia. However, it is important to remember that this is only a small-scale operation and broad scale eradication from Australia would need substantial funding, research, active management and cooperation between different land users to ever completely rid Australia of the rabbit.
Want more info? Check out these recourses:
- Gregory S. D., Henderson W., Smee E., Cassey P. (2014). ‘Eradications of vertebrate pests in Australia: A review and guidelines for future best practice.’ PestSmart Toolkit publication, Invasive Animals Cooperative Research Centre, Canberra, Australia.
- McLeod, S. R., Saunders, G. (2014). ‘The European rabbit; Australia’s worst mammalian invader’ in H. Prins, & I. Gordon, (eds), Invasion Biology and Ecological Theory: Insights from a continent in transformation, Cambridge University Press, UK, pp. 429-451.
- NSW Government, (2011). ‘Rabbits – fact sheet.’ accessed 28/4/15, available at: http://www.environment.nsw.gov.au/pestsweeds/RabbitFactsheet.htm
- Stevens, C. (2014). ‘Macquarie Island brought back from the brink.’, WWF: Australia, 15 April, accessed 1/5/15, available at: http://www.wwf.org.au/?9600%2FMacquarie-Island-brought-back-from-the-brink
- Williams, C. K., Parer, I., Coman, B. J., Burley, J., Braysher, M. L. (1995). ‘Managing Vertebrate Pests: Rabbits.’ Bureau of Resource Sciences/CSIRO Division of Wildlife and Ecology, Australian Government Publishing Service, Canberra.
- Zukerman, W. (2009). ‘Australia’s battle with the bunny.’ ABC Science, 8 April, accessed 30/4/15, available at: http://www.abc.net.au/science/articles/2009/04/08/2538860.htm
- Fight to save Antarctic Island, (2011). Video, Australian Broadcasting Corporation, 16 May, accessed 28/4/15, available at: http://www.abc.net.au/7.30/content/2011/s3218459.htm
- Rabbit Revival, (2009). Video, Australian Broadcasting Corporation, 14 April, accessed 30/4/15, available at: http://www.abc.net.au/landline/content/2008/s2538137.htm