Tag Archives: dingo

Interspecific and Geographic Variation in the Diets of Sympatric Carnivores: Dingoes/Wild Dogs and Red Foxes in South-Eastern Australia

Authors: Naomi E Davis, David M Forsyth, Barbara Triggs, Charlie Pascoe, Joe Benshemesh, Alan Robley, Jenny Lawrence, Euan G Ritchie, Dale G Nimmo and Lindy F Lumsden.

Abstract

Dingoes/wild dogs (Canis dingo/familiaris) and red foxes (Vulpes vulpes) are widespread carnivores in southern Australia and are controlled to reduce predation on domestic livestock and native fauna.

We used the occurrence of food items in 5875 dingo/wild dog scats and 11,569 fox scats to evaluate interspecific and geographic differences in the diets of these species within nine regions of Victoria, south-eastern Australia.

The nine regions encompass a wide variety of ecosystems. Diet overlap between dingoes/wild dogs and foxes varied among regions, from low to near complete overlap. The diet of foxes was broader than dingoes/wild dogs in all but three regions, with the former usually containing more insects, reptiles and plant material. By contrast, dingoes/wild dogs more regularly consumed larger mammals, supporting the hypothesis that niche partitioning occurs on the basis of mammalian prey size.

The key mammalian food items for dingoes/wild dogs across all regions were black wallaby (Wallabia bicolor), brushtail possum species (Trichosurus spp.), common wombat (Vombatus ursinus), sambar deer (Rusa unicolor), cattle (Bos taurus) and European rabbit (Oryctolagus cuniculus). The key mammalian food items for foxes across all regions were European rabbit, sheep (Ovis aries) and house mouse (Mus musculus).

Foxes consumed 6.1 times the number of individuals of threatened Critical Weight Range native mammal species than did dingoes/wild dogs. The occurrence of intraguild predation was asymmetrical; dingoes/wild dogs consumed greater biomass of the smaller fox.

The substantial geographic variation in diet indicates that dingoes/wild dogs and foxes alter their diet in accordance with changing food availability.

We provide checklists of taxa recorded in the diets of dingoes/wild dogs and foxes as a resource for managers and researchers wishing to understand the potential impacts of policy and management decisions on dingoes/wild dogs, foxes and the food resources they interact with.

Davis NE, Forsyth DM, Triggs B, Pascoe C, Benshemesh J, Davis NE, Forsyth DM, Triggs B, Pascoe C, Benshemesh J, Robley A, Lawrence J, Nimmo DG, Ritchie EG, Lumsden LF (2015) Interspecific and Geographic Variation in the Diets of Sympatric Carnivores: Dingoes/Wild Dogs and Red Foxes in South-Eastern Australia. PLoS ONE 10(3): e0120975. PDF DOI

Resolving the value of the dingo in ecological restoration

Authors: Thomas M Newsome, Guy-Anthony Ballard, Mathew S Crowther, Justin A Dellinger, Peter J S Fleming, Alistair S Glen, Aaron C Greenville, Chris N Johnson, Mike Letnic, Katherine E Moseby, Dale G Nimmo, Michael Paul Nelson, John L Read, William J Ripple, Euan G Ritchie, Carolyn R Shores, Arian D Wallach, Aaron J Wirsing and Christopher R Dickman.

Abstract

There is global interest in restoring populations of apex predators, both to conserve them and to harness their ecological services.

In Australia, reintroduction of dingoes (Canis dingo) has been proposed to help restore degraded rangelands. This proposal is based on theories and the results of studies suggesting that dingoes can suppress populations of prey (especially medium- and large-sized herbivores) and invasive predators such as red foxes (Vulpes vulpes) and feral cats (Felis catus) that prey on threatened native species. However, the idea of dingo reintroduction has met opposition, especially from scientists who query the dingo’s positive effects for some species or in some environments.

Here, we ask ‘what is a feasible experimental design for assessing the role of dingoes in ecological restoration?’ We outline and propose a dingo reintroduction experiment — one that draws upon the existing dingo-proof fence—and identify an area suitable for this (Sturt National Park, western New South Wales).

Although challenging, this initiative would test whether dingoes can help restore Australia’s rangeland biodiversity, and potentially provide proof-of-concept for apex predator reintroductions globally.

Newsome TM, Ballard G, Crowther MS, Glen AS, Dellinger JA, Fleming PJS, Greenville AC, Johnson CN, Letnic M, Moseby KE, Nimmo DG, Nelson MP, Read JL, Ripple WJ, Ritchie EG, Shores CR, Wallach AD, Wirsing AJ, Dickman CR (2015) Resolving the value of the dingo in ecological restoration, Restoration Ecology PDF DOI

Science Network Western Australia: Thousands predicted to die along state barrier fence

The south-west of WA is a global biodiversity hotspot. The state barrier fence has had a questionable impact on controlling pest species and extending it would likely cause more harm than good.

Read more, including reader comments, on the Science Network Western Australia website.

A comment on the influence of dingoes on the Australian sheep flock

Authors: David Forsyth, Andrew Woolnough, Dale Nimmo, Euan Ritchie, Malcolm Kennedy, Anthony Pople and Ian Watson

Published in: Australian Veterinary Journal, volume 92, number 12 (December 2014)

Allen and West recently proposed that dingoes (Canis dingo, including hybrids with feral dogs C. lupus familiaris) are a critical causal factor in the decline of Australia’s sheep (Ovis aries) flock and implied that dingoes would cause the rangeland sheep industry to disappear within 30−40 years.

We agree that dingo predation can reduce the profitability of affected sheep properties and has important negative social effect on rural communities, and that exclusion fences and a range of lethal control methods are options for reducing those negative effects.

However, we argue that the importance of dingoes as a cause of the decline in Australia’s sheep flock has been overstated.

Forsyth D, Woolnough AP, Nimmo D, Ritchie EG, Kennedy M, Pople A, Watson I (2014) A comment on the influence of dingoes on the Australian sheep flock. Australian Veterinary Journal, 92: 461–462. PDF DOI

Top dogs: Australian predators can provide 24-7 feral cat control

Feral cats are devastating our wildlife, so we need a long-term, sustainable solution. This is where Australia’s natural predators come in.

Feral cats are decimating native wildlife. Could the introduction of apex predators be part of the solution? Image credit Timo via Flickr.

Feral cats are decimating Australian wildlife. Could the introduction of apex predators be part of the solution? Image credit Timo via Flickr.

A few moments on the internet will reveal that, as companion animals, cats are rivalled only by dogs. Our love affair with them is hardly surprising: they are elegant, graceful and affectionate animals. But they are also highly adaptable and successful hunters. Sadly our soft spot for them brings with it disastrous consequences for smaller wildlife species, particularly mammals, birds and reptiles.

Cats are wreaking havoc on our native wildlife, from northern Australia’s Kimberley to southern Australia’s Alps: nowhere is unaffected. Along with other threats such as habitat loss and fire, cats are pushing many native animals to the brink of extinction.

How serious is the cat problem? It’s been estimated that there may be as many as 15 million feral cats in Australia, each killing about five native animals per night: a nightly total of around 75 million native animals. And it’s not just feral cats doing the damage; that adorable Fluffy has a sinister side too. It often isn’t recognised that there is abundant and diverse native wildlife in and around many Australian cities and towns, including bandicoots, sugar gliders, quolls, koalas, parrots, water dragons and snakes. The development of remotely triggered camera traps has provided ample evidence that such wildlife frequently falls victim to domestic cats on their nightly excursions.

For a long time our other invasive predator of note, the European red fox, was seen as enemy number one to our wildlife, particularly mammals, but there’s a growing realisation that its many meals are eclipsed by those of cats, both feral and owned. Globally, cats are rated at 38th and red foxes at 99th on the IUCN’s list of 100 of the World’s Worst Invasive Alien Species.

And it’s not just cats’ appetites that are doing the damage. Cats are the primary host of the parasite Toxoplasma gondii, which can infect most mammals and birds, causing the potentially fatal disease toxoplasmosis (toxo). Even when not lethal, toxo can impact wildlife populations indirectly, through effects that include impaired vision, disorientation, loss of coordination, anorexia, lethargy, fever, skewed offspring sex ratios and abortion. Most bizarrely, animals infected with toxo are often attracted to the smell of cats and hence are more likely to be killed and eaten by them; a kind of parasite-driven mind control.

So what can we do to reduce the damage done by cats and mitigate this national conservation disaster? The most urgent needs are for vigorous education and awareness campaigns about the impacts of cats on wildlife, and tighter regulations and enforcement around responsible cat ownership. This should include mandatory desexing, the imposition of night-time curfews and containment of cats within pet owners’ properties at all times.

In addition, a number of on-ground solutions are already available or under consideration; there is no doubt that a range of measures will be essential. These include the development of cat-specific poison baits and release of a cat-specific virus. However cat control through disease and poison programs are unlikely to be effective long-term, as natural selection will favour disease-resistant and cautious cats which will result in rapid population bounce-back. After all, cats are known for their smarts, being more attracted to moving prey and suspicious of foreign objects. Under good conditions, furthermore, they can reproducequickly and bountifully.

Fencing can effectively exclude cats from habitats and provide wildlife refuges, and they play a critical role in holding the line for species such as bilbies, already teetering on the edge of extinction. However the use of fencing as a regular and ongoing strategy for wildlife conservation in our vast country will not only be logistically challenging (perhaps impossible) but also forbiddingly expensive. More fences will also result in it becoming harder and harder to see bilbies, bandicoots and many other native species in the wild. What a sad outcome for our nation and what an indictment of our allowing cats to reign supreme and unchecked!

Cue the predator

Why are cats able to run rampant? A significant reason is the lack of balance that now characterises our ecosystems. A crucial step is likely to be returning native top predators, in particular dingoes and Tasmanian devils, to landscapes, so that they can resume their important ecological roles. Scientific research (pdf) is strongly suggesting that dingoes not only kill cats but also instill fear in them, which means that they avoid areas and times where dingoes are active. Hence dingoes can provide a 24-hour-a-day, seven-day-a-week, cat control service.

If we want to conserve our iconic and globally unique wildlife then we need to work with, rather than against nature, and supporting more positive management of dingoes and returning Tasmanian devils to mainland Australia for their biodiversity benefits (pdf)would be one of the best and most cost effective things policy-makers could do now. Non-government conservation organisations such as the Australian Wildlife Conservancy are already leading the way.

In 1995 the USA and Canada worked together to reintroduce wolves to Yellowstone for their ecosystem benefits. The success of this bold step is now the stuff of legend. Isn’t it time we had our ‘Yellowstone moment’ and began restoring Australia’s ecosystems to some of their former glory?

This post was originally published on the ABC. Click here to read the original article, including reader comments and extra content.

Ecological connectivity or Barrier Fence? Critical choices on the agricultural margins of Western Australia

Authors: Keith Bradby, James A Fitzsimons, Andrew Del Marco, Don A Driscoll, Euan G Ritchie, Jenny Lau, Corey JA Bradshaw and Richard J Hobbs.

Abstract

Western Australia’s State Barrier Fence represents a continuation of colonial era attitudes that considered kangaroos, emus and dingoes as vermin.

Recent plans to upgrade and extend the Barrier Fence have shown little regard for ecological impacts or statutory environmental assessment processes.

EmusAtBarreirFence

Emus are known to travel up to 1000 kilometres between seasons. This is what happens when their migration is impeded by the West Australian State Barrier Fence. Image credit : Graeme Chapman.

Bradby K, Fitzsimons JA, Del Marco A, Driscoll DA, Ritchie EG, Lau J, Bradshaw CJA Hobbs RJ (2014) Ecological connectivity or Barrier Fence? Critical choices on the agricultural margins of Western Australia. Ecological management and restoration 15(3) 180–190 PDF DOI

Radio National Bush Telegraph: Does kangaroo shooting lead to plagues?

Parts of Australia are teeming with over-abundant herbivores, such as feral goats and native kangaroos. But is shooting the best approach? Or can a well-managed dingo population lead to a well-managed kangaroo population?

Summary and reader comments on the Radio National website