There are an estimated 1 billion domesticated dogs in the world. Most are owned animals – pets, companions or working animals who share their lives with humans. They are the most common large predator in the world. Pet cats trail far behind, at about 220 million.
We are all too aware of the negative effects of cats, both owned and feral, on wildlife. Feral dogs too are frequently seen as threats to biodiversity, although dingoes can have a positive role. By contrast, our pet dogs often seem to get a free pass.
This is, unfortunately, based more on feelings than data. Our beloved pet dogs have a far greater, more insidious and more concerning effect on wildlife and the environment than we would like to be the case.
In our new research, we lay out the damage pet dogs do and what can be done about it.
Dogs are predators. They catch many types of wildlife and can injure or kill them. Their scent and droppings scare smaller animals. Then there’s the huge environmental cost of feeding these carnivores and the sheer quantity of their poo.
We love our pet dogs, but they come with a very real cost. We have to recognise this and take steps to protect wildlife by leashing or restraining our animals.
The predator in your home
Dogs are domesticated wolves, bred to be smaller, more docile and extremely responsive to humans. But they are still predators.
Pet dogs are responsible for more reported attacks on wildlife than are cats, according to data from wildlife care centres, and catch larger animals.
Pet dogs off the leash are the main reason colonies of little penguins are nearing collapse in Tasmania.
In New Zealand, a single escaped pet dog is estimated to have killed up to 500 brown kiwis out of a total population of 900 over a five-week period.
Once off the leash, dogs love to chase animals and birds. This may seem harmless. But being chased can exhaust tired migratory birds, forcing them to use more energy. Dogs can kill fledglings of beach-nesting birds, including endangered birds such as the hooded plover.
The mere presence of these predators terrifies many animals and birds. Even when they’re on the leash, local wildlife are on high alert. This has measurable negative effects on bird abundance and diversity across woodland sites in eastern Australia.
In the United States, deer are more alert and run sooner and farther if they see a human with a leashed dog than a human alone.
Several mammal species in the United States perceived dogs with a human as a bigger threat than coyotes.
Dogs don’t even have to be present to be bad for wildlife. They scent-mark trees and posts with their urine and leave their faeces in many places. These act as warnings to many other species. Researchers in the US found animals such as deer, foxes and even bobcats avoided areas dogs had been regularly walked compared to dog exclusion zones, due to the traces they left.
Beach-nesting birds such as hooded plovers are vulnerable to off-leash dogs, who can easily trample eggs, kill hatchlings or scare off the parents.Martin Pelanek/Shutterstock
Keeping dogs healthy and fed has a cost
The medications we use to rid our pet dogs of fleas or ticks can last weeks on fur, and wash off when they plunge into a creek or river. But some of these medications have ingredients highly toxic to aquatic invertebrates, meaning a quick dip can be devastating.
Researchers have found when birds such as blue tits and great tits collect brushed-out dog fur to line their nests, it can lead to fewer eggs hatching and more dead hatchlings.
Then there’s the poo. In the US, there are about 90 million pet dogs, while the UK has 12 million and Australia has 6 million.
The average dog deposits 200 grams of faeces and 400 millilitres of urine a day. This translates to a tonne of faeces and 2,000 litres of urine over a 13 year lifespan. Scaled up, that’s a mountain of waste.
This waste stream can add to nitrogen pollution in waterways, alter soil chemistry and even spread diseases to humans and other wildlife. More than 80% of the pathogens infecting domesticated animals also infect wildlife.
Dogs largely eat meat, meaning millions of cows and chickens are raised just to feed our pets. Feeding the world’s dogs leads to about the same emissions as the Philippines and a land use “pawprint” twice the size of the UK.
No one likes thinking about this
People love their dogs. They’re always happy to see us. Their companionship makes us healthier, body and mind. Many farms couldn’t run without working dogs. We don’t want to acknowledge they can also cause harm.
Dogs, of course, are not bad. They’re animals, with natural instincts as well as the domesticated instinct to please us. But their sheer numbers mean they do real damage.
Many of us have a large dog-shaped blind spot. Little Brutus wouldn’t have done something like that, we think. But Brutus can and does.
Choosing to own a dog comes with responsibilities. Being a good dog owner means caring not just for the animal we love, but the rest of the natural world.
The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.
As Labor continues to target 82 per cent renewables by 2030, the amount of wind and solar in regional communities will continue to scale up. But balancing community and environmental interests has been challenging for companies and governments.
Amazon, Google and Microsoft are building datacentres in water-scarce parts of five continents
Amazon, Microsoft and Google are operating datacentres that use vast amounts of water in some of the world’s driest areas and are building many more, the non-profit investigatory organisation SourceMaterial and the Guardian have found.
With Donald Trump pledging to support them, the three technology giants are planning hundreds of datacentres in the US and across the globe, with a potentially huge impact on populations already living with water scarcity.
It surprised many Australians when the Coalition announced a plan straight from the progressive side of politics: force large gas companies to reserve gas for domestic use – at a lower cost than they could sell it for overseas.
As a populist move during a cost-of-living election, it’s a good one. Australia’s gas producers sell 70% of gas extracted on the east coast overseas under long-term contracts, even as southeastern states such as Victoria face possible gas shortages. Western Australia has long had an effective policy requiring up to 15% of offshore gas to be reserved for domestic use.
After a fortnight’s delay, the Coalition has now publicly released the modelling behind its policy. Undertaken by Frontier Economics, the modelling indicates that reserving 50 to 100 petajoules of gas in the first year would cut wholesale prices by 23%. This would mean a 15% drop in prices for large-scale users – but only a 7% fall for household gas bills and a 3% fall in electricity bills.
This doesn’t sound like much, because it isn’t. Gas prices soared during the Ukraine war and haven’t yet returned to their pre-war levels. Labor has dubbed the plan “gaslighting”, and will rely instead on a gas policy released last year to open up more gasfields and build import terminals. Gas producers don’t like the Coalition’s plan, and neither does billionaire Liberal benefactor Gina Rinehart. Dutton’s plan isn’t crazy – it’s just not likely to make a big difference.
The Coalition has proposed what it calls an East Coast Reservation Scheme, with the goal of progressively decoupling Australia’s east coast gas market from the volatile international market.
It has two parts. First, it would require new exporters, in the first year of operation, to reserve an additional 50–100 petajoules for the domestic market. Second, it would create a gas security charge, to be imposed on gas producers seeking to export “additional” (non-contracted) gas on the international market.
This would give gas producers an incentive to sell non-contracted gas to the domestic market, because they would get greater profits selling in Australia, even at a lower base price.
Further, the policy would prevent gas producers from charging domestic buyers international prices, setting a competitive price.
In effect, the gas security charge is akin to a levy or a reverse tariff. The levy can be avoided if producers supply up to 100 petajoules to domestic markets. That’s about as much gas as New South Wales’ gas pipelines deliver each year – 101 petajoules (PJ) as of 2022–23, or the equivalent of 26 full liquefied natural gas (LNG) carriers, which hold about 3.8 PJ on average.
What are the issues with this plan?
There are legitimate concerns. First, the policy does not directly address domestic gas pricing and won’t help with the cost of living crisis. Over time, it could create a more competitive domestic market, but the fact producers could make marginally more money selling gas on the domestic market doesn’t guarantee change.
Second, the policy does not directly address the looming gas supply crisis. That’s because existing gas producers would not be legally obliged to commit to more gas domestically – they could still export it. The obligation to commit an additional 50-100 petajoules to the domestic market only applies to gas exporters in their first year of operation.
If policymakers want to solve the supply crisis, they would be better served by imposing direct export controls in the form of a clear gas reservation mandate. This works, as Western Australia’s long experience shows.
How did we get here?
When Russia invaded Ukraine in 2022, it led to huge spikes in global gas prices and shortages in Europe as the world moved away from Russian gas.
In the 2010s, Australia had already been ramping up gas production. But in the wake of the Ukraine war, Australia became a major gas exporter. Producers traded as much gas as possible on the international market, selling it for over A$40/GJ. Meanwhile, Australia’s coal production was falling.
Domestic gas demand shot up, and prices went from $8 to $30 a gigajoule. In response, the Albanese government introduced an emergency price cap for the wholesale gas market, prohibiting producers from entering into supply contracts with domestic purchasers for prices above a cap, currently set at $12/GJ. While the cap did partly insulate domestic consumers, it was always intended as a temporary measure.
The Australian Competition and Consumer Commission recently predicted a gas supply shortfall of up to 40 petajoules in the southern states as early as September due to declining production in Victoria and South Australia as well as higher demand. Without access to uncontracted Queensland gas, supply will run very low. This is a significant energy security risk, and one the Coalition’s gas policy doesn’t directly address.
Victorian residents are more reliant on gas than other states – and shortfalls are looming.M-Production/Shutterstock
What’s next?
Australia is one of the world’s top three LNG exporters. The fact a gas giant could be facing domestic shortages is both unnecessary and embarrassing. Reaching this point represents decades of policy failure.
Reserving gas for domestic use works for the west coast, and it would work for the east. But the Coalition’s plan is not quite a gas reservation scheme. It doesn’t create a comprehensive reservation mandate and questions remain about its capacity to address domestic pricing and supply.
At present, it seems like a lot of effort without great benefit. Will households really notice their gas bill is 7% cheaper?
Samantha Hepburn does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
