Author: Euan Ritchie

By Tim Doherty (Deakin University), Aaron J Wirsing (University of Washington), Chris Dickman (University of Sydney), Dale Nimmo (Charles Sturt University), Euan Ritchie (Deakin University), and Thomas Newsome (Deakin University)

Humans and their canine companions share many close bonds. Wolves (Canis lupus) were the first animal domesticated by people, some time between 15,000 and 50,000 years ago.

There are now an estimated 1 billion domestic dogs across their near-global distribution.

Domestic dogs include feral and free-ranging animals (such as village and camp dogs), as well as those that are owned by and completely dependent on humans (pet dogs).

Our latest research reveals that the ecological “pawprint” of domestic dogs is much greater than previously realised.

Using the IUCN Red List of Threatened Species, we counted how many species are negatively affected by dogs, assessed the prevalence of different types of impacts, and identified regions with the greatest number of affected species.

Dogs are third-most-damaging mammal

We found that dogs are implicated in the extinction of at least 11 species, including the Hawaiian Rail and the Tonga Ground Skink. Dogs are also a known or potential threat to 188 threatened species worldwide: 96 mammal, 78 bird, 22 reptile and three amphibian species. This includes 30 critically endangered species, two of which are classed as “possibly extinct”.

These numbers place dogs in the number three spot after cats and rodents as the world’s most damaging invasive mammalian predators.

Even though dogs have an almost global distribution, the threatened species they are known to affect are concentrated in certain parts of the globe. South-East Asia, South America, Central America and the Caribbean each contain 28 to 30 threatened species impacted by dogs. Other hotspots include Australia, Micro/Mela/Polynesia and the remainder of Asia.

Lethal and non-lethal impacts

Predation was the most commonly reported impact of dogs on wildlife. The typically omnivorous diet of dogs means they have strong potential to affect a diversity of species. For instance, dogs killed at least 19 endangered Kagu (a ground-dwelling bird) in New Caledonia in 14 weeks. Threatened species with small population sizes are particularly vulnerable to such intense bouts of predation.

Aside from simply killing animals, dogs can harm wildlife in other ways, such as by spreading disease, interbreeding with other canids, competing for resources such as food or shelter, and causing disturbances by chasing or harassment. For example, contact with domestic dogs increases disease risk for endangered African Wild Dogs in Kenya.

Part of the problem is that when wild animals perceive dogs as a threat, they may change their behaviour to avoid them. One study near Sydney found that dog walking in parklands and national parks reduced the abundance and species richness of birds, even when dogs were restrained on leads.

None of the Red List assessments mentioned such indirect risk effects, which suggests that their frequency is likely to be much higher than reported.

Friend and foe

Despite their widespread and sometimes severe impacts on biodiversity, dogs can also benefit some species and ecosystems.

For example, in Australia, the closely related dingo (Canis dingo) can suppress populations of introduced predators such as red foxes (Vulpes vulpes), and in doing so can benefit smaller native prey. It is possible that domestic dogs could perform similar ecological roles in some situations.

In some regions, dogs and their keen noses have been trained to help scientists find threatened species such as Tiger Quolls. Elsewhere they are helping to flush out and control feral cats.

An emerging and exciting conservation role for dogs is their growing use as “guardian animals” for wildlife, with the remarkable story of Oddball being the most well known.

Managing the problem

Dogs not only interact with wildlife, but can also attack and spread disease to humans, livestock and other domestic animals. As such, managing the problem requires looking at ecological, cultural and social perspectives.

Some of the regions with high numbers of species threatened by dogs are also hotspots for urbanisation and road building, which make it easier for dogs to access the habitats of threatened species. Urban development increases food waste, which feeds higher numbers of dogs. As dogs expand into new areas, the number of species they impact is likely to grow.

We can protect wildlife by integrating human health and animal welfare objectives into dog management. Vaccination and desexing campaigns can reduce disease risk and overpopulation problems. We should also focus on responsible dog ownership, removing dogs without owners, and reducing access to food waste.

Given the close relationship between humans and dogs, community engagement should form the basis of any management program. More research is needed to get a better picture of the scale of the problem, and of how dogs interact with other threats such as habitat loss. Such actions are critically important for ensuring the conservation of wildlife threatened by dogs around the world.

This article was originally published on The Conversation. Read the original article, including reader comments.

By Euan Ritchie (Deakin University) and Arian Wallach (University of Technology Sydney)

On any given night, many farmers go to sleep worrying about what they might wake up to in the morning. Few things are more stressful than seeing your livestock, such as sheep, lying dead or seriously injured in the paddock. Sometimes dingoes, free roaming and unowned (“feral”) dogs, and domestic dogs, or their hybrids, are responsible for such a scene. But what’s the best way to deal with this situation?

The Victorian government is set to reinstate a dingo and wild dog bounty scheme as a way to reduce livestock, especially sheep, being attacked and killed, in response to calls from farming and shooting groups.

Just what is a dingo?

One of the problems with managing dingoes is that the boundary between them and “wild dogs” is contentious. Some have even claimed that there are no pure dingoes in Victoria.

Defining what dingoes are is harder than you might think. There is considerable variation in how dingoes look, for example, in terms of their overall size and colour, as is common with many other members of the dog family (canids).

And if a dingo isn’t considered 100% “pure”, containing genes from domestic dogs, should hybrids be managed differently to dingoes?

Research suggests “pure” dingoes do exist in Victoria, albeit in smaller numbers than other regions.

Notably though, genetic samples in Victoria have been collected largely from areas close to towns, where there are likely more hybrid dogs, and less so from deep within Victoria’s more remote natural regions (the mallee, alpine, and Gippsland forests), where dingoes are often sighted.

Two other recent studies are important in the Victorian context. One suggests dingo characteristics prevail even within hybrids and another has found there are two distinct dingo populations. Importantly, the south east dingo population is at increased risk of extinction.

Many ecologists would argue that splitting hairs about dingo genetic “purity” is a moot point, because what really matters is what dingoes and dingo-dog hybrids are doing in the environment. This is because dingoes are known to have important ecological roles, including the suppression of feral species (such as cats, pigs, and goats), red foxes, and kangaroos.

How are wild dogs and dingoes managed in Victoria?

The decision to reinstate a dingo and wild dog bounty in Victoria is vexed. In 2007 the Victorian government established protection of dingoes, due to conservation concerns about the species, with hybridisation between dingoes and domestic dogs identified as a threatening process.

As a result, dingoes in Victoria are listed as a threatened species under the Flora and Fauna Guarantee Act 1988 and protected under the Wildlife Act 1975.

In Victoria wild dogs are classed as pest animals and can be legally controlled. However, the Victorian Department of Environment states that “dingoes are visually indistinguishable from wild dogs, making it impossible to ensure they are not inadvertently destroyed in wild dog control programs in any given area where both exist” and “dingoes are protected wildlife and it is an offence under the Wildlife Act 1975 to take or kill protected wildlife without an authorisation to do so”.

Management misfire

Legal and species identification issues aside, do bounties and lethal control of predators actually work?

In short, scientific evidence suggests the answer is largely no (see for instance here, here, here, here, and here).

There are a range of reasons cited for why bounties fail. These include:

• an inability to sufficiently reduce numbers of the the target species and hence their impact, due to rapid breeding and/or immigration from other areas
• corruption by those claiming bounties, whereby animals claimed for bounty payments have not actually been killed in the area where the bounty is intended to benefit
• an inability to access some animals over large and/or remote areas
• a disincentive to completely eradicate animals as this removes the source of income
• disruption of predator social structures causing higher livestock predation.

Investing in predator-friendly farming

So what solutions do we have that might allow productive farms without the need to kill predators? A range of nonlethal solutions exist for protecting livestock, including improved husbandry techniques (such as corralling and herding), and in particular, a growing body of research suggests guardian animals provide a great step forward.

Nonlethal methods to protect livestock are also consistent with a growing social demand that both domestic and wild animals are treated humanely and ethically on farms.

Predator-friendly farming is growing across Australia, as you can see in the image above. Large livestock on large landholdings, such as beef cattle on thousands of square kilometre stations, are reducing conflict by enabling dingo packs to stabilize and by supporting healthier cows that are better able to defend their calves (top left).

Smaller farms are also employing protective strategies, including guardian dogs, even if the livestock species is large, such as dairy cows and buffalo, because lethal control on neighboring farms continues to disrupt the dingo’s social structure (bottom left).

Technological innovations in nonlethal methods for protecting livestock from predators have been developed in Australia and used worldwide, such as “Foxlights” (top right). And vulnerable stock, such as chickens, are being successfully protected with guardian dogs and enclosures (bottom right).

There are substantial gains to be made for agriculture, people, wild animals and the environment if decision-makers use scientific evidence and ethical analysis, rather than responding to lobby groups, as the basis for taxpayer-sponsored actions.

Education is also a key aspect of any change, and scientists are being proactive here too, providing guidance on new approaches to rangeland livestock management that are supported by research.

The fact is, bounty schemes don’t work. If instead the substantial funds currently being invested in bounties were invested in supporting farmers to move to more long-term, cost-effective, and more environmentally-friendly solutions, we may all be able to sleep better at night.

This article was originally published on The Conversation. Read the original article, including reader comments.

It’s raining feral cats and wild dogs on social media!

Today I spoke to Radio National’s Patricia Karvelus about what’s been happening in my social media feeds, from dog bounties to hashtag #scicomm.

Streaming audio via Radio National website

Today on Triple R, I had the honour and pleasure of sharing the airwaves with Australian Nobel Laureate Professor Peter Doherty.

Listen via 3RRR Radio on Demand (requires Flash)