Once a curiosity for sport, foxes, first introduced to Australia in 1870, have become a common invasive species. Introduced by British aristocracy to control game populations and support hunting practices, as they did in Great Britain, foxes readily adapted to their new ecological niche with devastating effects. By 1940, these animals had taken over nearly every inch of appropriate territory on the continent. This rapid expansion gave rise to significant questions regarding their impact on native wildlife.
Local elites introduced foxes in Geelong, Victoria. They set off to re-create the hunting culture that they had known in England. In just 70 years, foxes moved across all of southeastern Australia. They even made it to very remote areas such as the Pilbara region of Western Australia. Their population increased quickly, eventually leveling off at an incredible mid-20th century estimate of 1.7 million people. Today, foxes occupy nearly 80 percent of Australia, showing their incredible adaptability.
Ecological Consequences
The rapid spread of foxes was catastrophic for native wildlife. In fact, studies have shown that red foxes have contributed to the extirpation of 16 native mammal species since their introduction. As their populations increased, they became an apex predator across many different ecosystems, outcompeting natives for food and habitat.
Dr. Damien Fordham noted that the difficulty in attributing extinctions to predation by feral animals was a key challenge. His research will help direct future conservation efforts for Australia’s most at-risk mammals.
“What we hope then is to be able to use that information for restoration and to be able to reverse the population declines of so many animals in Australia,” – Damien Fordham
It’s a key issue, and local environmental coalitions and landscape control boards have made drastic strides in fox management nationally. Managing a species that has spread so widely poses daunting challenges.
Mapping the Spread
A federal program has closely tracked the advance of foxes through Australia. Maps at the highest resolution show where they have become widespread, which helps paint a picture of their colonization, giving vital information to conservationists.
These intuitive maps give an extraordinary visual representation of the recent spread of the red fox. They offer important lessons for understanding why some native species have outlasted others in the face of increasing competition for longer.
“By having historic maps and high resolution reconstructions of the colonisation of Australia by invasive species, it gives us an inkling or an insight into how we lost so many species so quickly,” – Sean Tomlinson
No matter how hard the management authorities and the community conservationists try, controlling foxes is a Herculean feat. As artist John Virtue remarked, it was very limiting to work with a pest so prevalent.
Ongoing Management Efforts
Because foxes can easily find food in urban environments, leading urban areas to have the highest concentrations of foxes, managing the fox population becomes more difficult. Few people realize that a temperate fox density can be a mere four to eight foxes per square kilometer.
“When a pest is very widespread, you’re not really going to try and contain its further spread,” – John Virtue
Fox populations are doing very well throughout the country. To counter, researchers and conservationists are hard at work developing proven strategies to minimize their impact on native species.
“Urban areas have got the highest numbers because there’s plenty of food sources available, so you’re dealing with a lot of foxes, and most people don’t realize how many are in their local neighbourhood,” – John Virtue
As fox populations continue to thrive across Australia, researchers and conservationists strive to develop effective methods for mitigating their impact on native species.
