In the UK at least, the RSPB aren't fussed about cats being free. https://www.rspb.org.uk/birds-and-wildlife/advice/gardening-for-wildlife/animal-deterrents/ca

In the UK at least, the RSPB aren't fussed about cats being free. https://www.rspb.org.uk/birds-and-wildlife/advice/gardening-for-wildlife/animal-deterrents/cats-and-garden-birds/are-cats-causing-bird-declines/ https://www.rspb.org.uk/birds-and-wildlife/advice/gardening-... >there is no clear scientific evidence that such mortality is causing bird populations to decline >of the millions of baby birds hatched each year, most will die before they reach breeding age. This is also quite natural