Anonymous
Thank you for reminding everyone of this. I live near highpoint and there has been a constant influx of abandoned cats over the years, especially following the tear downs. I have shelter, food/water and even a litter box outside so the neighbors don’t receive little gifts in the garden. I’ve also had all the one’s I watch out for, neutered.
It requires so little effort compared to the benefits. I have never had a single rodent in or around my house. To those worried about birds, my dog has found and brought only one into the house. No way to tell how it met its demise. Another time, I heard a bird squeal and was able to scare the cat into dropping it. This is over the course of several years.
I know it’s possible more have been caught, but I have not found any other evidence of it. I still have three different bird species brave enough to nest every spring and close to a dozen different types, visit in large numbers all summer long.
As to the net effect of increasing the colony, if you trap and neuter, the numbers automatically decline. Left alone, they almost all survive long enough to have a litter or two.