The European settlers who arrived on our shores in the late 1700s were not alone. They brought new animals with them too. Species that weren't necessarily compatible with our native wildlife. Two of the most problematic introduced species – the red fox and feral cat – have proved extremely destructive. Predation by feral cats is now the greatest threat to Australia's terrestrial mammals. Cats have contributed to the extinction of 28 species and subspecies and threaten the survival of another 100 mammal species and subspecies. And we’re yet to develop an effective way of controlling them across the Australian landscape that they prowl. The opportunistic red fox is equally well adapted to a variety of environments and has few natural predators. It has a particular appetite for our small and medium sized mammals and ground-nesting birds, but will also dine on reptiles, amphibians and invertebrates. On the threatened species listed under the Environment Protection and Biodiversity Conservation Act 1999, foxes are considered a threat to 14 bird, 48 mammal, 12 reptile and two amphibian species.
Predation by feral cats and foxes is one of the greatest threats to Australian threatened species, especially critical weight range mammals, birds, reptiles and frogs. Cats have been recorded to eat or kill over 400 vertebrate species in Australia and, together with foxes, they have played a major role in the decline of many native animals. Cats can also carry diseases like toxoplasmosis and sarcosporidiosis, which can not only be passed on to native animals but humans and domestic livestock too.
What we're doing
With our partners, WWF-Australia is actively working to protect species threatened by foxes and feral cats so we can swing the balance back in their favour. Predator control is critical. WWF has developed a plan to save 21 species by 2021. This plan aims to protect key species from not only the effects of feral predators, but also from the impact of climate change, habitat loss and inappropriate fire regimes.
In the Kimberley region
We’re working on the species that cats are likely to impact, such as - the black-footed rock-wallaby, nabarlek, monjon, bilby, golden bandicoot, and the northern quoll. We’re also working on the protection of the Gouldian finch and purple-crowned fairy wren, which we also fear feral cats may be impacting on.
Again, with our partners and volunteers, we’re working in Queensland on the northern bettong, where cats are a real threat to this species. It’s also reasonable to include foxes as a threat to the northern bettong. They’ve been discussed as a possible reason for bettong disappearance from the southern part of their range, and there are worries that fox numbers are increasing within current northern bettong habitat.
In Southwest Australia
We’re focusing on the black-flanked rock-wallaby, woylie (brush-tailed bettong), quokka and numbat. One example of species protection against introduced predators happened after discovering that the rock-wallaby population at Nangeen Hill had plummeted. The WA Department of Parks and Wildlife and WWF-Australia supporters joined forces to fund a specially designed five-kilometre predator-proof fence around the perimeter of Nangeen Hill Nature Reserve. Exclusion fences are a great way to create sanctuaries for native animals, however they need to be monitored constantly to ensure that they are not breached.
Another way to help Australia’s species combat feral predators is to provide a safe haven for important animals to reproduce. WWF was able to provide support to Kanyana Wildlife Rehabilitation Centre to help improve their breeding enclosures for the critically endangered woylie or brush-tailed bettong. The woylies housed in these facilities are from Tutanning, one of four woylie populations classified as vital to maintaining the genetic diversity of the species. Sadly, all four populations have declined drastically during the past decade and the Tutanning population is now believed to be extinct in the wild. By helping these animals breed in captivity we’re ensuring that important genetics can live on even when the wild population has been decimated by introduced cats and foxes.
Cats may have arrived as early as the 17th century following Dutch shipwrecks. They were certainly well established in the wild by the 1850s and intentional releases during the late 1800s — in an attempt to control mice, rats and rabbits — bolstered this population. Cats are highly adaptable animals and have spread across the continent. They now occupy 99% of Australia, including the harshest of environments , and can breed in any season and survive with limited water. European red foxes were introduced to Victoria for recreational hunting in 1855. By the early 1870s, wild fox populations were well established and, over the next century, foxes spread across most of Australia, with the exception of Tasmania. The red fox will scavenge and prey on whatever food is available. Widespread control programs have made an impact, especially in Western Australia, where native animals have a natural resistance to the poison used. Here, the Western Shield fox baiting program is successfully undertaken across a large area.
While there has been some success with baiting programs to control fox numbers, large-scale control of cats is proving very difficult and encouragingly the Australian Government’s recently launched Threatened Species Strategy explicitly includes tackling predation by feral cats as a key priority.