This is a fleeting idea but it is based on what I hope is logically deduction. We know that brightly coloured collars worn by domestic cats allowed outside help to protect birds. The birds pick up on the movement of the brightly coloured collar as the cat stalks them. This gives them time to escape. It indicates that a sharp, coloured pattern is more noticeable to birds than a camouflaged pattern. We also know that the best cat coat for camouflage is the spotted or mackerel tabby. This is the original wildcat coat, only the wildcats tabby coat has less contrast.
Domestic cat coats have evolved through mutations over the preceding 10,000 years to become far less efficient as camouflage: quite the opposite. A lot of domestic cat coats nowadays are not made for camouflage. This should help protect birds. The tabby coat is still very common.
On that basis, what sort of domestic cat coat might be more easily picked up by a bird? I’ve come to the conclusion quite quickly that a harlequin cat with ginger or red spots will be the nearest match to a brightly coloured collar. A ‘harlequin cat‘ is a cat with a predominantly white coat and a few colour-patches. The picture shows you:
An alternative would be a parti-coloured cat with a substantial amount of white. So, for example, a calico cat is likely to be picked up by birds more so than a tabby cat. Or the bicolor cat is less good as camouflage.
It is, potentially, a little thing that a person might consider before adopting a cat companion for the first time. A lot of cat caregivers are concerned about their cat preying on birds and other animals for that matter. Birds seem to be placed on a pedestal compared to other animals when it comes to domestic cat predation.
The bottom line would be that a cat with a poorly camouflaged coat is the sort of cat which might protect birds if their owner allows them outside unsupervised. The ultimate deterrent is to keep a cat indoors but there is still resistance to this by a significant section of society.
SOME MORE ON CALICO CATS: