Understanding the Impact: What Roaming Cats Are Doing to Wildlife
Australians love their pets—but too often, our affection for cats is blinding us to the harm they cause.
There’s a common sentiment: “My cat wouldn’t hurt anything.” We want to believe it. We need to believe it. But the truth is, even the gentlest, best-fed cats are natural-born hunters. And the numbers don’t lie.
Research by the Biodiversity Council, BirdLife Australia, Invasive Species Council, and several top universities found that:
71% of pet cats are allowed to roam freely.
Of those, 78% actively hunt, with most owners unaware—because cats only bring home about 15% of what they kill.
In urban areas, roaming pet cats kill 30 to 50 times more native wildlife per km² than feral cats do in natural environments.
We’re not talking about a few unfortunate birds. We’re talking about 546 million animals killed each year—many of them native, vulnerable, and irreplaceable. Roaming cats have contributed to 34 mammal extinctions and continue to threaten another 230 species today.
But physical predation is only part of the damage.
Cat scratches and bites can transmit deadly bacteria like Pasteurella multocida and Bartonella henselae, leading to infection, sepsis, or even death in wildlife. Cats also spread toxoplasmosis, a parasite that causes blindness, neurological disorders, and miscarriages in marsupials and birds.
This is Wynta, a Willie Wagtail. She was found in the mouth of a cat. Though her owners were convinced she hadn’t been bitten, Wynta tragically died not long after. A single puncture or even unseen trauma can be fatal. This is why containment matters.
And it doesn’t end there.
Just the presence of cats can change wildlife behaviour in lasting ways. Exposure to roaming cats causes PTSD-like changes in some species, including heightened stress, reduced reproductive success, and chronic fear responses. Animals spend more time hiding and less time foraging, resting, or caring for their young—all of which can decimate populations over time.
So no, it’s not true that your cat wouldn’t attack. They might—and they often do.
But there is a way forward. A way to love your pet and protect wildlife.
Please don’t mistake this message as anti-cat. I truly love cats. I had a beautiful girl named Luna—sweet, affectionate, and endlessly curious. I wanted to give her a safe, enriching home, but the truth was… she was a Houdini. No matter how hard I tried, she found ways to escape, both the house and her catio. It broke my heart, but ultimately, I made the painful decision to rehome her with someone who had a fully enclosed catio and could keep her secure. It wasn’t easy, but it was right—for Luna, and for the wildlife around us.
Because love isn’t just about keeping them close—it’s about protecting them, and everything they touch.
What You Can Do
Visit SafeCat.org.au—a practical, positive resource for pet owners who want to do better. You’ll find advice on:
Transitioning your cat to indoor life
Building secure outdoor enclosures (“catios”)
Enrichment tips to keep cats happy, healthy, and stimulated
The science behind cat containment and wildlife protection
Indoor cats live longer. They avoid traffic, disease, injuries, and fights. And Australia’s wildlife gets a chance to recover.
We can all be part of the solution. Let’s choose kindness, responsibility, and awareness—for our pets, and for the wild lives that depend on us.