By Imogen Howse A remote Scottish island has been overrun by wild cats, causing a rescue operation and worries for the local wildlife. After two locals from Barra in the Outer Hebrides, Scotland died, more than 20 cats were left to roam around their home and barn. The felines have since multiplied, and with kitten season coming up, experts are worried about the impact on the island’s rare birds. The owners of the house, who live on the mainland, have tried to feed the cats but can’t keep it up. They’ve asked local animal charities for help, and Western Isles Support for Cats and Kittens (WISCK…