I've been wondering how long do most UK rarities survive upon finding themselves in these islands? Obviously there will be major differences between taxa/species - you would expect say a Vega Gull to survive quite happily for years, whereas a Tanager spp. might not last more than a few days or weeks. I'd imagine predation and climate to be very significant risks for smaller species and that most would succumb quite quickly, but what about the more mobile and/or adaptable? I'm intrigued by how long something like eg. the famous Hebridean white-throated needletail might have survived had it not collided with the wind turbine, and where it might have gone...