Australia is a prime example of how bad things can go if we introduce new species of animals or plants to a new environment. In today’s post I want to write a bit about how the Red Fox (Vulpes vulpes) were introduced to Australia, and how much chaos it brought to the local ecosystems.
Two red foxes. Image by Keven Law, posted with the Creative Commons Attribution-Share Alike 2.0 Generic license.
How the red foxes got to Australia
The red fox was originally brought to Australia in 1871, and were released in Victoria (some sources claim earlier, as far back as the 1830s). They were intended to be used for recreational hunting, but quickly spread around the country. They spread to Queensland by 1907, and Western Australia by 1912, and have since been found on all of mainland Australia. Right now they are expected to be found in about 76 % of the continent, so they are pretty much found at all places.
The red fox naturally became an apex predator on mainland Australia, and luckily for the fox, rabbits were also introduced and spread all around Australia at the same time, so it never had a problem with getting food. The foxes were generally not as successful in areas with a lot of dingoes (Canis dingo), but they were still able to be population areas with dingoes nearby, just not as good as in areas without them.
Image by Alan D. Wilson, posted with the Creative Commons Attribution-Share Alike 3.0 Unported license.
The damages the red fox has caused to Australia
The Department of Environment and Conservation in Australia estimates that invasive predators are responsible for at least ten native species, so they are a serious threat to the local fauna. They have been directly linked to the decline and extinction of desert rat-kangaroo (Caloprymnus campestris), a small hopping marsupial found in desert regions of Central Australia. The paper I linked to pretty much shows how the population of the rat-kangaroos (Family Potoroidae) decline when the foxes enter the region is correlated, and even shows how the foxes were the major perpetrators, not drought like other people had assumed.
A desert rat-kangaroo. Image is Public Domain.
The Department of Environment and Conservation also believes that the foxes are able to predate 77 different native species, which includes 10 threatened species. They are generally able to kill prey that are up to 5 kilo in body weight, which means that they are able to kill most small and medium-sized marsupial and rodent species, as well as many different species of birds (and their eggs).
Will the foxes even predate on koalas?
Everyone loves koalas, and it seems that the foxes does as well, but they would rather eat than pet them. Until 2016 no one expected the red foxes to be able to climb trees in order to get their paws on koalas, but this behavior was documented by Valentina Mella at the University of Sydney, Australia during her koala research. She found several cases of red foxes climbing up the eucalyptus trees, and believe that they do this in order to predate on koalas! The cameras she had did not capture footage of a fox actually killing a koala, but it showed the fox with hunting behavior in a eucalyptus tree, which makes it very likely. that it was in fact in the hunt for koala meat.
No one can really know what happens when we release plants and animals into new regions
The point that I really want to make with this post is about how complex the ecosystems often are, and how even small changes can have a huge effect on many different species. The hunters who wanted to shoot some foxes did not anticipate that they would be responsible for the extinction of 10 different endemic species, or that it would have lots of different ecological consequences for over three quarters of Australia.
While Australia is a very complex example due to it not really having all that many predators, similar consequences can be seen in other parts of the world when new species are introduced. There are countless of examples of areas that have had their local ecology altered or even destroyed by invasive species, and species that have gone extinct because they were killed or outcompeted by an introduced species.
Can Australia get rid of the red fox?
It seems very unlike that Australia will ever be able to get rid of the red fox at this point, but the government seems to be trying its best to get rid of it. It is legal to hunt it in all states, and even poison it, but the eradication of the species has still proven very difficult due to the fact that they are nocturnal, breed easily and don’t always eat the poison.
Lots of dead foxes in Victoria, Australia. Image by Wikimedia user Mattinbgn, posted with the Creative Commons Attribution 3.0 Unported license.
Some scientists want to use dingoes or even reintroduce Tasmanian devils to the mainland Australia in order to reduce the fox population, which might actually work. Speaking of Tasmania, this little island south of Australia is very afraid that the foxes will get a foothold on this island, and have very strict policies in place to prevent this from happening. If you spot a fox in Tasmania you are urged to call the “Invasive Species Hotline”, which will deploy a hunting team to get rid of the fox. It sounds a bit over the top, but this seem to actually work a lot better than just incentivizing the hunters to shoot them when they are bothered.
Thanks for reading
Thanks for reading about how a few hunters were able to completely destroy several native Australian species by releasing foxes into the nature! I hope you enjoyed the post despite the grimness of it.