Foxes

Introduced to Australia in the mid 1800s for hunting purposes, the European red fox (Vulpes vulpes) can now be found in every part of the Australian mainland, except the tropical north. The fox is regarded as one of the most elusive animals in the world, which is probably why people are generally surprised to learn that there are an estimated 7 million foxes in Australia - that's around one fox for every 3 people. It is estimated that it took only 100 years for foxes to achieve their current distribution in Australia, which is not surprising when you consider the following:

• foxes are extremely adaptable, being equally at home in coastal dunes, bushland, urban environments and agricultural landscapes. In Australia the population density in urban areas is estimated to be around 12/km2 (in Melbourne as high as 16/km2)
• foxes are sexually mature from about 10 months of age
• they mate once a year in winter and produce on average four pups but can have as many as ten per litter
• around the age of 6 to 9 months foxes will disperse from where they were born. Females usually disperse 3-15km and males 11-43km, although distances much longer have been recorded
• foxes are primarily carnivorous scavengers and opportunistic predators that are well adapted to utilising a varied diet
• depending on breeding and immigration rates, fox populations can withstand up to 75% yearly mortality rates.

Australia's wildlife has not evolved in the presence of foxes and consequently usually lacks the necessary skills to avoid fox predation. To give an idea of the potential impact of foxes in Australian ecosystems, consider the following:

• any animal up to 5.5kg may be taken as prey, which includes the majority of Australia's mammals and almost all of its reptiles, birds and insects
• a single fox eats an average 400g of food per night, or 150kg per year, made up of a huge range of human scraps, mammals, reptiles, birds and invertebrates
• the fox is known to have caused the extinction of at least 6 Australian mammals and is in the process of driving a further 10 animal species to the brink of extinction, and
• through predation of eggs and hatchlings, the fox is one of the most significant threats to endangered loggerhead turtles nesting on Sunshine Coast beaches.

Foxes also regularly prey on domestic poultry and stock, which are usually easy targets for the hunting prowess of foxes. In 2004 it was estimated that the cost of foxes to the environment and the agricultural sector was in the order of almost $230 million.

The mortality of young foxes is high (up to 80% in the first year) with most deaths caused by road-kill, disease, trapping, poisoning and food shortage. In its native Europe and North America, distemper and mange are thought to be significant natural controlling factors but their role in the Australian environment is not currently known.

Despite the high mortality rate, its inherent capacity to breed quickly and establish new territories has resulted in a fox population in Australia that is at least stable and probably increasing in some areas.