Where did the Dingo go? By Lauren Sweet - a podcast by Liz Hadly

Hi I’m Lauren and your listening to “Where did the Dingo Go?”
We often think of Australia as a land hopping with kangaroos, wallabies, bilbies and other fuzzy critters. What most people don’t realize is that, despite this apparent diversity, in the last 2 centuries Australia has seen 19 of its unique mammal species become extinct (Johnson 2006) –that’s about half of all mammal extinctions worldwide in that period (Johnson et al. 2007). And Australia's mammals are still in great danger because of the slow demise of the wily dingo.
About 4000 years ago man brought the dingo to Australia. Since then, the dingo has gone from ancient companion to top predator(Ritchie & Johnson 2009).While you might think the Dingo is a pesky carnivore that eats livestock, gobbles up native animals and is generally the equivalent of the big bad wolf, the truth is that the dusty colored dingo is anything but bad. Since becoming top dog, dingoes have lived in relative harmony with the many small, rare Australian marsupials-you know, those cute mammals with pouches. This is mainly because dingoes are sparsely distributed and, because of a large body size, are specialized to hunt larger prey (Ritchie & Johnson 2009). To a dingo, a wallaby just doesn’t have enough meat on it to be as appetizing as a kangaroo. The same, however, cannot be said for the invasive red fox.
When Europeans introduced the red fox in 1855 for some recreational sporting (Dprt. of the Enviro. and Heritage (Australia) 2004) they could not have suspected that foxes would soon become the plague of Australia’s small mammals. In fact, foxes have been blamed for the extinction of many of Australia’s species. (Short 1998) (Johnson & VanDerWal 2009) (Johnson 2006)(Glen & Dickman 2005). The fox is a prey generalist, meaning he is not picky about what he eat. Rabbits, wallabies, birds—it all goes down the hatch. Foxes, because of their smaller size have more babies than dingos, more often (Dprt. of the Enviro. and Heritage (Australia) 2004) (Corbett 2004) and don’t need as much space per individual, so they can exist at high densities. Combine these three things—an undiscriminating appetite, lots of babies and the ability to pack many individuals into a small area-- and you can see how the fox is having a terribly negative effect on vulnerable ground dwelling marsupials (Ritchie & Johnson 2009).
Interestingly however, where dingoes exist, threatened marsupials are able to survive predation by foxes (Johnson et al. 2007) (Johnson & VanDerWal 2009). In fact, knowing where dingoes exist can be one of the best predictors of how well vulnerable species are doing (Wallach et al 2009) (Johnson et al. 2007). Turns out that the dingo is nowhere near the bad guy in this story. If anything he is the opposite, the good guy—protector of marsupials.
Why? Well, it turns out that dingoes play a very important role in culling fox populations. Dingoes actively attack foxes and, as a result of this persecution, foxes make a great efforts to avoid dingoes and dingo territory (Ritchie and Johnson 2009) Thus dingoes create a safety zone for the local small animal population(Ritchie & Johnson 2009) (Johnson and VanDerWal 2009).
Food webs are complicated and its important for us to understand that a top predator doesn’t effect only its prey but also impacts other predators and smaller animals that the apex carnivore doesn’t even directly associate with. In Australia, it is truly a dog-eat dog world—or in this case a dog-eat-fox.
Besides preserving Australia’s biodiversity, controlling the fox population also has significant economic impacts. The sheep industry in Australia produced 1/5 of the world’s wool in 2010. Yet, in some areas, foxes may kill up to 1/3 of lambs (Saunders 1995). And of course there is also the loss in ecotourism as more and more unique Australian species end up in the stomachs of foxes( Saunders 1995).
The dingo is as iconic to Australia as the wallaby, or the wombat and yet, despite the necessary role it play as protector of other iconic Australian mammals, the dingo is too often treated as a pest. Dingos are subjected to poisoning or otherwise exterminated and kept at low population levels (Johnson et all 2007) (Wallach et al. 2009). All of which hurts the dingo and those animals preyed upon by foxes. The dingo is a powerful tool in the saving of Australia’s fuzzy marsupials (Ritchie & Johnson 2009). But, dingoes are disappearing, and if they do, Australia will loose much more than just some wild dogs.

Thanks for listening

Cited Sources
Corbett, Laurie. 2004. Dingo. Canids: Foxes, Wolves, Jackals and Dogs. International Union for Conservation of Nature and Natural Resources.
Glen, Alistair S. and Dickman, Chris R. 2005. Complex interactions among mammalian carnivores in Australia, and their implications for wildlife management. Biological Review, 80: 387–401.
“Invasive species fact sheet: European red fox (Vulpes vulpes)”. Department of the Environment and Heritage (Australia). 2004.
Johnson, Chris N. 2006. Australia’s Mammal Extinctions: A 50 000 Year History. Cambridge University Press, Cambridge.
Johnson, Chris N., and VanDerWal, Jeremy. 2009. Evidence that dingoes limit abundance of a mesopredator in eastern Australian forests. Journal of Applied Ecology 46: 641–646.
Johnson, Chris N., Isaac, J.L. and Fisher, D.O. 2007. Rarity of a top predator triggers continent-wide collapse of mammal prey: dingoes and marsupials in Australia. Proceedings of the Royal Society B: Biological Sciences, 274: 341–346.
Ritchie, E. G. and Johnson, C. N. 2009. Predator interactions, mesopredator release and biodiversity conservation. Ecology Letters, 12: 982–998.
Saunders, Glen 1995. Managing Vertebrate Pests: Foxes. Canberra: A.G.P.S.
Short, Jeff. 1998. The extinction of rat-kangaroos (Marsupialia:Potoroidae) in New South Wales, Australia. Biological Conservation 86.3: 365-377.
Wallach, Arian D., Murray, Brad R., O’Neill, Adam J. 2009. Can threatened species survive where the top predator is absent?. Biological Conservation, 142: 43-52.
Photo: Creative Commons: Henry Whitehead

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