I spoke to Jaana Dielenberg – Science Communication Manager, The University of Queensland (National Environmental Science Program)
“Collectively, roaming pet cats kill 390 million animals per year in Australia… On average, each roaming pet cat kills 186 reptiles, birds and mammals per year, most of them native to Australia. Collectively, that’s 4,440 to 8,100 animals per square kilometre per year for the area inhabited by pet cats…”
Article here: https://theconversation.com/one-cat-one-year-110-native-animals-lock-up-your-pet-its-a-killing-machine-138412