New research has indicated feral cats kill 316 million birds and pet cats kill 61 million birds in Australia every year.
That’s more than one million birds in Australia each day.
More than 99 per cent of these casualties are native birds.
Recently published in the science journal Biological Conservation, the research was undertaken by a team of leading Australian environmental scientists from the Threatened Species Recovery Hub of the National Environmental Science Programme and compiles evidence from over 200 separate studies.
Australia’s acting threatened species commissioner Sebastian Lang said the evidence was “extremely important and of great concern”.
“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,” Mr Lang said.
A strategy that was first implemented in Western Australia’s Peel region in late 2015, early 2016.
Mr Lang said while the number of birds killed by pet cats was also high, he commended pet owners who contained their cats instead of letting them roam freely.
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.
The estimates are based on results from around 100 studies across Australia, each sampling cat density, and another set of nearly 100 studies across the country that assessed cat diet.
Charles Darwin University lead researcher Professor John Woinarski said that while previous research has looked at the impact cats are having on Australia’s mammals, this is the first nation-wide 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,” Mr Woinarski said.
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, which is 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.”
“For Australian birds, cats are a long-standing, broad-scale and deeply entrenched problem that needs to be tackled more effectively,” Mr Woinarski said.
Mr Lang said the new research emphasised the need to continue work to reduce the impact of cats on Australia’s native biodiversity.