A birding friend posted some delightful photos of the various owls she's seen in the UK. This caused me to reflect upon the fact that I only need four really rare species for the full UK set: Pigmy, Scops, Tengmalm's and Hawk. I should think the chances of me seeing any of these is virtually non-existent!
Then I started to think about the other 'sets': I've seen all six Grebes, all three Pratincoles, all four Skuas, all ten Crows and so on... I wonder if anyone among the top 'listers' has seen every bird on the BOU / UK400 lists? (Excluding extinct birds, of course!)