A fashion relic of the late eighties and nineties, the humble scrunchie has found a new lease on life preventing the slaughter of wildlife by domestic cats.

In a new study, West Australian researchers found putting a scrunchie-like collar on cats reduced the amount of native wildlife killed by more than half.

Murdoch University PhD student Catherine Hall spearheaded the research which observed the behaviour of 114 cats for two years.

Over the course of the study, the owners of the cats froze everything their pets caught, both with and without the collar.

She said the results showed the scrunchie-esque neckwear reduced the number of birds, reptiles and amphibians captured by the cats by 54 per cent.

"Bright colours are very noticeable to songbirds, they should see the cats further away, allowing them to escape earlier," Ms Hall said.

"Because it's based on colour and vision, cats won't be able to learn to make it stop working.

"Unlike what people say about bells. [They say] that cats can learn to make them less effective over time."

The study found the collar did not make a difference to the number of mice and other mammals caught as their colour vision was not as good, meaning owners could still use their cats to catch garden pests.

"For people who want their cats to catch small rodents like rats and mice but don't want them to catch birds, this is an effective device to use," Ms Hall said.

Serpentine resident Robyn Brown's two cats, Chocco and Milo, were recruited for the study.

She said they used to be active wildlife hunters and would often leave birds like wrens on her doorstep.

"We were very concerned about that. We've tried everything. We've tried double bells and all kinds of things and we've tried locking them in at night time," she said.

But she said since the collars were placed on her cats more than two years ago, they had not caught a single bird.

"We just can't believe it. We're very happy," Ms Brown said.

"I've always loved cats ... I didn't want to give up cats because I had birds as well, and I loved having them in the environment, but now I can have both."