Australasian Science: Australia's authority on science since 1938

Cats Kill More Than One Million Australian Birds Per Day

Feral cats kill 316 million birds and pet cats kill 61 million birds in Australia every year. More than 99% of these casualties are native birds.

The estimates, published in Biological Conservation, are based on results from nearly 100 studies of cat density across the country, and another set of nearly 100 studies that assessed cat diet nationally.

Lead researcher Prof John Woinarski of Charles Darwin University said that while previous research has looked at the impact cats are having on Australia’s mammals, this is the first nationwide assessment of the impact of cats on Australia’s birds. “Everyone knows that cats kill birds, but this study shows that, at a national level, the amount of predation is staggering, and is likely to be driving the ongoing decline of many species,” Woinarski said.

The study also found that the highest rates of cat predation on birds is on Australia’s islands and in remote arid Australia, where the number of birds killed by cats each year can reach 330 birds per square kilometre.

In a second study, the research team also looked at which bird species are at most risk from cat predation. They found records of cats killing 338 native bird species – almost half of Australia’s native bird species. This included 71 threatened bird species.

“We found that the birds most likely to be killed by cats are medium-sized birds, birds that nest and feed on the ground, and birds that occur on islands or in woodlands, grasslands and shrublands,” Woinarski said. “For Australian birds, cats are a long-standing, broad-scale and deeply entrenched problem that needs to be tackled more effectively.”

Australia’s Acting Threatened Species Commissioner, Sebastian Lang, added: “Our knowledge of the impacts of cats on threatened mammals was a major stimulus for our first-ever national Threatened Species Strategy, which prioritised actions to control feral cats. This new research emphasises the need to continue working to reduce the impact of cats on our native biodiversity.”