I can recall seeing my first one in the early 60's here in England when I was a kid. I checked all my bird books but couldn't find it. By the early 70's they were fairly common and soon put on the pest lists. They had spread in from continental Europe by natural means. They are not a great problem and I only shoot them round farm buildings if asked to do so. They are fine to eat. It's amazing how fast they spread but then they seem to find a natural limit. Lagopus.....