I found this link interesting. The cat tracker images showing where a cat has actually gone in the course of a week are amazing.
On the Dunedin study: >"A year-long study of 208 cats in urban Dunedin showed that they kill more birds, skinks, geckos, and weta than rats and mice."
>"37 Dunedin cats that were known to be prolific hunters, [...] without collars, the cats caught 378 animals, including 82 birds"
>"There is the well-documented case of a lighthouse-keeper’s cat causing the extinction of the Ste-phens Island wren. And near Tongariro National Park, one feral cat was filmed killing 102 short-tailed bats in the Rangataua forest, on the side of Mt Ruapehu, in just seven days in 2010."
https://www.forestandbird.org.nz/sites/default/files/2018-05...
https://zslpublications.onlinelibrary.wiley.com/doi/abs/10.1...
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2486....
The success of native breeding, conservation, and re-introduction programmes has been in spite of the country's feral and domestic cats.
The lighthouse story is tragic and maddening. While I opted not to adopt a new cat when my last one died, I don't support the predator-free approach to conservation.
Why?
If hypothetically (since I'm not familiar with the data) they're killing some birds but those bird populations remain healthy, is that a problem?
That TheOatmeal comic always comes to mind.
It's the same same story in Australia. I had multiple vocally Green neighbors in a vocally Green suburb of Melbourne who let their cats have free rein. The mutilated bird carcasses that littered the area were testament to that misguided liberty. Around election time the Greens mailers even included "protecting our pets" as one of its platform items, while at the same time advising voters to rank parties with actual environmental policies, such as the socialists, nearly last.
It's very frustrating, folks can't acknowledge that 'cute and familiar' is causing enourmous ecological harm because it's out of sight, out of mind.