I may well have fumbled.
There I was stalking some Greenland Whitefronts with Greylags around Bragar/Shawbost/Labost among the squally snow showers and a big falcon came in over the coast and flew on towards Arnol. All the geese went up because of it. In my experience they don’t flinch for Peregrines.
It aroused my suspicions enough that I digi-binned it, as it was pale and big – but not pure white. It clearly wasn’t a white Gyr, or juv, but I did wonder about it being a grey one (Icelandic?). It certainly had the bulk, and I have not seen a Peregrine as pale as this before, or as stocky among other things. Maybe a falconers bird? Doubtful but see below.
If I hadn’t pfaffed digi-binning it I would have had better views, and seen more features. So much for the pressure of getting an image these days. As it is I suspect I can’t do much more with it.
I strongly suspect the ten rare men of BBRC don’t accept 30 second bins views of a flyover grey Gyr in a snow storm. Darn it. One that got away?
You need to be cautious even though we have had a November grey Gyr before
but a real potential pitfall is an escaped falconers bird. Tiree has had a white Gyr with jesses, St Kilda a hybrid escape, and then you get tricky candidates like this (which at least has jesses on it so nailed the origin if not the identification)