The NPR headline is catchy but the underlying study is dogged by questions.<p>The cited study (<a href="https://doi.org/10.1111/acv.12563;" rel="nofollow">https://doi.org/10.1111/acv.12563;</a> sci-hub.tw has a copy) has some methodological flaws:<p>* The cat studied were were not randomly selected; they were chosen by "local volunteers". There may be confounding variables that explain part of the effect and so turn the observed effects from being statistically significant to not being statistically significant.
* The data on kills was self-reported, allowing bias to creep in.
* All the cats were English-speaking.
* Only 10 un-neutered pet cats were studied. I don't know if being neutered would increase, decrease, or have no effect on the kill rate, but the subject is not discussed.<p>I also question the conclusion that cats have a significant impact on local fauna.<p>* The average kill rate for a pet cat was (roughly) less than two animals per week, which doesn't seem very high. I'm left with the feeling that the authors had to resort to killings/area to make the results impressive.
* The authors did not report on the total size of the home ranges of cats compared to total area. So, for example, if the ratio was 1:1000, then so what? If the ratio was 1:20, then house cat might have a significant affect on local fauna.<p>Finally, I have a question about the presentation of the data: Figure 2b does not indicate that "75% of cats spent 90% of their time in disturbed habitats". The graph indicates that 500+ (out of 875 cats) spent between 95% and 100% of their time in developed habitats. Perhaps the y-axis is mislabeled, but even if it is, the graph does not match what the authors say.