A NEW paper by Mike Letnic from the University of Sydney adds more weight to the argument that the best way to save Australia’s small native rodents, in particular the dusky hopping mouse, is to protect the dingo because it also preys on foxes and foxes are more damaging to the small cute and furies than the dingo.
Landholder Jim Inglis reckons the scrub tick does a better job than the dingo at controlling foxes in higher rainfall regions – foxes that kill the pademelons on his property.
The European fox, Vulpes vulpes, was introduced into Australia in the early 1870s for recreational hunting purposes. Along with the domestic cat, Felis catus, the species has been implicated in the extinction or range reduction of many Australian native marsupials and rodents.
The dingo, Canis lupus dingo, is a descendant of the wolf and thought to have been in Australia for a bit longer than either the fox or cat – about 4,000 years longer.
Dingoes will eat foxes and cats, but they also eat lambs and other livestock. Baiting programs have traditionally been more effective against dingoes than, for example, foxes to the extent that there is now an Australian Dingo Conservation Association – concerned the species could be driven to extinction.
An increasing number of ecologists are claiming that one way of saving small native marsupials and rodents is to actually protect dingoes, because they suppress numbers of foxes.
Mike Letnic from the School of Biological Science at the University of Sydney is one of the latest to publish findings along these lines. His latest research, just published in the journal ‘Animal Conservation’, claims that maintaining or restoring dingo populations may be a useful strategy to mitigate the predatory impacts of foxes on small and medium sized mammals in arid environments.
Dr Letnic qualifies his findings though, acknowledging, that the mass extinction of mammals from the Australian deserts has occurred in the last 100 years, despite the presence of dingoes, makes it clear that dingoes are not a ‘silver bullet’ for biodiversity conservation.”
A regular reader of this weblog and landholder, Jim Inglis, sent me the picture of the headless Red Necked Pademelon, Thylogale thetis, killed on his lawn on May 1, 2009, by a fox. He has also written that foxes are thriving alongside dingoes at his place which has a higher rainfall than the Strzelecki Desert where Dr Letnic carried out his research.
According to Mr Inglis,
“Dingoes are bad news for the natives that are their natural prey but could possibly help the preservation of these smaller animals that were more the focus of foxes and cats.
“As Dr. Lentic says, they certainly aren’t any silver bullet. Though they possibly restrict cats and foxes in open desert country, these two species “play them off a brake” in rough scrub and forest country.
“What controls cats and foxes in coastal mountain bushland more than dingoes is the scrub tick which luckily no one has yet developed a way to eradicate though I believe they are still foolishly trying.
“If people get a scrub tick they should extract it gently and put it back where they got it.”
Links and Notes
Not Available online:
Does a top-predator provide an endangered rodent with refuge froman invasive mesopredator?
M. Letnic, M. S. Crowther & F. Koch, Animal Conservation (2009) 1-11.
In arid environments, ecological refuges are often conceptualised as places where animal species can persist through drought owing to the localised persistence of moisture and nutrients. The mesopredator release hypothesis (MRH) predicts that reduced abundance of top-order predators results in an increase in the abundance of smaller predators (mesopredators) and consequently has detrimental impacts on the prey of the smaller predators. Thus according to the MRH, the existence of larger predators may provide prey with refuge from predation. In this study, we investigated how the abundance of an endangered rodent Notomys fuscus is affected by Australia’s largest predator, the dingo Canis lupus dingo, introduced mesopredators, introduced herbivores, kangaroos and rainfall. Our surveys showed that N. fuscus was more abundant where dingoes occurred. Generalised linear modelling showed that N. fuscus abundance was associated positively with dingo activity and long-term annual rainfall and negatively with red fox Vulpes vulpes activity. Our results were consistent with the hypothesis that areas with higher rainfall and dingoes provide N. fuscus with refuge from drought and predation by invasive red foxes, respectively. Top-order predators, such as dingoes, could have an important functional role in broad-scale biodiversity conservation programmes by reducing the impacts of mesopredators.