Much of this impact may be attributed to feral, unowned cats, but domestic cats contribute substantially to predation on wildlife in urban areas. Predation rates per area by domestic cats in residential areas are 28–52 times higher than predation rates by feral cats in natural environments (Legge et al., 2020). Urban areas support diverse wildlife including threatened species, with 46% of nationally threatened Australian animals (almost 200 species) occurring in urban areas (Ives et al., 2016; Soanes & Lentini, 2019). Pet cats have been documented as having caused local eradication of native species populations (Bamford & Calver, 2015; Legge, Woinarski, et al., 2020), and even a single domestic cat can have major impacts on population decline and reproductive failure in a bird colony (Greenwell, Calver, & Loneragan, 2019).

[–] chicken@lemmy.dbzer0.com 2 points 2 days ago

I couldn't find a comparison between the two (though the first sentence of what you quoted seems to acknowledge it), but I did find this article which makes an argument that the meaningful ecological impact of cats is context dependent:

There is general agreement that free-roaming cats can pose a significant risk to wildlife populations; however, the credible evidence is quite clear that this risk is limited to very specific contexts (e.g., small islands) and even then is likely only one part of a larger story. Sweeping claims that lack necessary context (e.g., conflating island and mainland environments) confuse the issue and impede productive conversation about how best to manage free-roaming cat populations.

Published research and mainstream media accounts often focus on areas where free-roaming cats come into conflict with protected native wildlife species [46–49]. Although this attention is understandable, it’s important to recognize that such situations attract attention precisely because they are exceptional.

This seems consistent with what you linked, which also emphasizes islands and protected species. Maybe it makes sense to restrict outdoor cats specifically on islands.