"The impact of unsupervised #cats can be great. Feral cats are even believed to be behind the extinction of animals on several islands.

One study estimated that each year, cats kill 1.3 billion to four billion birds and 6.3 billion to 22.3 billion mammals."

https://www.cbc.ca/news/climate/what-on-earth-cats-birds-9.7141192

How many birds do cats actually kill? | CBC Climate Change News

In this issue of our environmental newsletter, we get the latest scientific estimate of how many birds cats kill each year; check out the forecast for this year's El Niño; and find out what's in the e-waste Canadians throw out (hint: a lot of good stuff).

CBC

@harold I have but one data point for a feral cat that was not only supervised by given a condo to survive SK winter.

https://cogdogblog.com/2025/11/crookers-the-cat-a-year-in-the-box/

Crookers is now a pampered house cat in Saskatoon ;-)