|Scottish wildcat or a hybrid? Photo by Peter G Trimming|
It can be difficult to see the difference in appearance between a Scottish wildcat hybrid and the purebred Scottish wildcat.
One fairly clear difference is in the tail. The wildcat has a thick tail with clear dark banding (4 rings) ending in a black tip. The rings nearer the root of the tail are fainter than those at the tip. The dorsal stripe that follows the spine stops at the beginning (root) of the tail.
The hybrid cat has a less thick tail and the dorsal banding follows through continuously from the cat's back to the tail.
There are other more subtle differences on the crown of the head where stripes run backwards to the body. On the wild cat they are "broad and wavy" while on the hybrid they are thinner and straighter. And on the rump of the hybrid the stripes have broken into spots.
Both are in cat fancy terms, mackerel tabby cats. The Scottish wildcat is a very stocky (cobby) looking cat. The domestic cat and hybrid are not as stocky it seems to me. Although people understandably find it difficult to tell the difference. This must impact the monitoring of the wildcat in terms of sightings.
The Kellas cat is a black (melanistic?) version of a Scottish wildcat hybrid.