(falco rusticolus)
The Gyr Falcon (or Gyrfalcon) is resident in Iceland, Norway and along the arctic tundra and has the distinction of being the largest falcon in the world, almost as big as a Buzzard. It is an occasional vagrant to Scotland and the UK.
In the winter of 2015/16 a white morph bird turned up in the Outer Hebrides and was seen intermittently in South and North Uist over many weeks. In March 2016 it became more predictable and spent a lot of time in the Balranald area of North Uist feeding on carrion, mostly dead geese and a dead Mute Swan. The unfortunate swan had flown into overhead electricity wires. At this point the bird became twitchable and after a couple of weeks of worrying I made the trip to North Uist.
On our first day the bird was eventually found at 17:10 feeding on a Greylag Goose on the north side of Loch Cloghearraidh giving rather distant views. On our second day the bird was not showing and as a last gesture before we had to head back to Lochmaddy for the ferry home we had a final drive past the dead swan location - and the bird was there ! The light was a bit dull with some drizzle in the air but I wasn't complaining.
Certainly a once in a lifetime opportunity !