Study Finds Cats Are Killing Machineshttp://www.ozpolitic.com/forum/YaBB.pl?num=1345002324cats are badhttp://www.ozpolitic.com/forum/YaBB.pl?num=1183443762Feral cats now cover 99.8% of Australiahttp://www.ozpolitic.com/forum/YaBB.pl?num=1483561037Should it be legal to kill pet cats on the loosehttp://www.ozpolitic.com/forum/YaBB.pl?num=1329450615Big cats prowl the bushhttp://www.ozpolitic.com/forum/YaBB.pl?num=1277554509
Cats kill more than 1 million birds in Australia every day, new estimates showhttp://www.abc.net.au/news/2017-10-04/cats-killing-one-million-birds-in-australia-every-day-estimates/9013960
Cats kill more than a million birds every day across Australia, according to our new estimate — the first robust attempt to quantify the problem on a nationwide scale.
Rates are highest in Australia's dry interior, suggesting that feral cats pose a serious and largely unseen threat to native bird species.
This has been a contentious issue for more than 100 years, since the spread of feral cats encompassed the entire Australian mainland.
In 1906 the ornithologist AJ Campbell noted that the arrival of feral cats in a location often immediately preceded the decline of many native bird species, and he campaigned vigorously for action:
"Undoubtedly, if many of our highly interesting and beautiful birds, especially ground-loving species, are to be preserved from total extinction, we must as a bird-lovers' union, at no distant date face squarely a wildcat destruction scheme."
To provide a first national assessment of the toll taken by cats on Australian birds, we have compiled almost 100 studies detailing the diets of Australia's feral cats.
The results show that the average feral cat eats about two birds every five days.
We conclude that, on average, feral cats in Australia's largely natural landscapes kill 272 million birds per year.
Bird-kill rates are highest in arid Australia (up to 330 birds per square kilometre per year) and on islands, where rates can vary greatly depending on size.
We also estimate (albeit with fewer data) that feral cats in human-modified landscapes, such as the areas surrounding cities, kill a further 44 million birds each year. Pet cats, meanwhile, kill about 61 million birds per year.
Overall, this amounts to more than 377 million birds killed by cats per year in Australia — more than a million every day.
In a related study, we also compiled records of the bird species being killed by cats in Australia. We found records of cats killing more than 330 native bird species — about half of all Australia's resident bird species.
In natural and remote landscapes, 99 per cent of the cat-killed birds are native species. Our results also show that cats are known to kill 71 of Australia's 117 threatened bird species.
Birds that feed or nest on the ground, live on islands, and are medium-sized (60-300g) are most likely to be killed by cats.
But our coarse assessment from many published estimates of local bird density suggests that there are about 11 billion land birds in Australia, suggesting that cats kill about 3-4 per cent of Australia's birds each year.
However, particular species are hit much harder than others, and the population viability of some species (such as quail-thrushes, button-quails and ground-feeding pigeons and doves) is likely to be especially threatened.
Overall, bird killings by cats seem to greatly outnumber those caused by humans.
In Australia, cats are likely to significantly increase the extinction risk faced by some bird species.
In many locations, birds face a range of interacting threats, with cat abundance and hunting success shown to increase in fragmented bushland, in areas with high stocking rates, and in places with poorly managed fire regimes, so cat impacts compound these other threats.
What can be done to reduce the impact? The Federal Government's Threatened Species Strategy recognises the threat posed by feral cats, albeit mainly on the basis of their role in mammal extinctions.