Rebirth of the Bilby

Easter in Australia involves not only the ubiquitous chocolate bunnies and eggs but also the native Bilby.

Since the 1990s chocolate bilbies have been appearing on in Australian shops around Easter time. These Easter Bilbies are an Australian alternative to rabbits, which in Australia are considered invasive pests and cause extensive damage to native species and ecosystems.

Karleah Trengove a PhD student with the Environment Institute has been studying these reintroduced populations, this is what she has to say about the bilby.

The Greater Bilby (Macrotis lagotis) has been greatly affected by European settlement. Originally distributed over 70% of the continent including Western Australia, South Australia, Northern Territory, Queensland and New South Wales, it is now believed they occupy only 20% of their former range (Southgate 1990). Unfortunately these populations still appear to be declining. The bilby is listed as nationally vulnerable, and was extinct in South Australia.

Recently though, efforts have been made to bring the bilby back to South Australia, and bilbies have been reintroduced at three locations within the state: the Arid Recovery Reserve, Venus Bay Conservation Park and an island offshore from Eyre Peninsula.

These releases were successful and bilbies established small populations at all three sites. I am currently conducting research on the Venus Bay and offshore island populations. My research is looking at breeding success, mating system, genetic diversity and burrow use of the bilbies in these populations, and hopefully my research will allow us to manage these populations for long term conservation of the bilby in South Australia and possibly help to plan any future releases.

The offshore island population has increased dramatically since release, and numbers are now estimated by my trapping results to be in the thousands. Bilbies here are in relatively high density, due to the high amount of food resources available to bilbies on the island and lack of predators, and animals are breeding well with a large number of young surviving. Similarly, the Venus Bay bilbies increased after release, however population growth has slowed in recent years as a number of cats have gained access to the park and are reducing survivorship of the young bilbies once they leave the pouch. There are still a large number of breeding adults in the population, so I hope that once the cats are caught the population will continue to flourish.

As one of these populations occurs on an island, and the other in a fenced off conservation park, there is only limited potential for population growth. These bilbies are not truly wild yet, as islands and fenced reserves are our only option for them at present as cats and foxes are so prevalent across the state. As cats and foxes appear to be a major cause of decline in bilby populations, we really need to put a lot of effort in to dramatically reducing the occurrence of these species before bilbies will ever be able to be released in to the wild, without fences to protect them.

The reintroductions have indeed proved to be successful in my view, and I hope my research will help us look to the future. Further reintroductions and better feral predator control are what I consider to be the next steps in increasing the number of bilbies in South Australia.

The Foundation for a Rabbit Free Australia, introduced the Easter Bilby in the early 1990s. Part of the proceeds from the sale of chocolate bilbies goes towards helping to rehabilitate the bilby back into the Australian landscape.

So this Easter instead of buying an invasive bunny, buy a bilby and support the rebirth of the bilby in the wild.

Rabbit Free Australia website www.rabbitfreeaustralia.org.au

Arid Recovery Program www.aridrecovery.org.au

Haighs Chocolates - http://haighschocolates.com.au/our_company/environment.html

Darrell Lea and Save the Bilby http://www.easterbilby.com.au/

Southgate, R.I. (1990a). Distribution and abundance of the Greater Bilby Macrotis lagotis Reid (Marsupialia: Peramelidae). In ‘Bandicoots and Bilbies’. (Eds. J.H. Seebeck, P.R. Brown, R.L. Wallis and C.M. Kemper) pp 293-302. (Surrey Beatty and Sons: Sydney.)