Billions of native animals fall victim to rampaging cats and foxes across Australia each year.
Scientists have put a number to the death toll for the first time.
A new study claims 697 million reptiles, 510 million birds and 1.4 billion mammals are killed each year.
It has previously been estimated one feral or pet cat can kill on average 1100 native animals each year.
Scientists say the study, led by Charles Darwin University in Darwin, again shows there needs to be better management of these introduced predators.
CDU adjunct researcher and lead author of the study, Dr Alyson Stobo-Wilson, said this research gives conservation managers valuable insights to guide responses to these two introduced predators.
“We already had good information about the cats’ impact on other species,” she said.
“This research gave us a clearer picture on the impact of both species nationally and in different and more remote environments.”
The study was undertaken by a team of 23 scientists from 16 universities and conservation agencies and is underpinned by over 50,000 poo and stomach samples and hundreds of densities counts for cats and foxes across the country.
The research was coordinated by the Threatened Species Recovery Hub of the federal government’s National Environmental Science Program.
CDU adjunct researcher and lead author of the study, Dr Alyson Stobo-Wilson.
Dr Stobo-Wilson said without a major increase in cat and fox control in Australia, these predators would continue to take a heavy toll on many species which are often also struggling from other threats such as habitat loss.
“Feral animal density is very important to understand the impact of foxes and cats in different environments,” she said.
There are an estimated 1.7 million foxes in Australia, ranging across 80 per cent of the country.
Researcher found foxes have been recorded killing 350 species of Australian native mammals, reptiles and birds.
“We found that fox densities and impacts are highest in temperate southern mainland Australia,” Dr Stobo-Wilson said.
“In temperate forests they collectively kill at least 1000 animals per square kilometre per year,” she said.
The highest toll by cats is around urban areas where the number of animals killed per square kilometre per year is 5670 killed by feral cats and 13,100 by pet cats.
The project’s senior scientist from Charles Darwin University’s Research Institute for the Environment and Livelihoods said that the findings highlight that targeted and integrated management of both foxes and cats is essential to conserving Australian wildlife.

Victoria has the only reward scheme for the shooting or trapping of foxes, with the annually tally approaching one million.
“Since foxes and cats were introduced to Australia by Europeans, they have played a major role in the declines and extinctions of many native animals,” Professor John Woinarski from CDU said.
“To be effective management programs need to be highly strategic as numbers of both of these predators can rebound quickly when management is not on-going or is piecemeal across a landscape.
“While some areas of Australia benefit from broad-scale baiting of foxes and similar control measures for cats, most of Australia has no effective management practices in place and so the impacts on biodiversity are likely to be severe, widespread and ongoing,” Professor Trish Fleming said.
Professor Fleming said foxes took a heavy toll on forest animals like possums and gliders, but cats were more numerous so had a wider diet than included more than 700 species of native mammals, reptiles and birds.
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The story Death toll among native animals from cats and foxes in the billions first appeared on Farm Online.