Flock of gulls. Possibly common gulls or kittiwake?
No interactions present.
I've tried blowing up the image, and while I agree that there is no evidence of white 'mirrors', there is also little evidence of black wing tips on many of the gulls - and not much visible evidence to confirm that most of them have heads!
They do look like Kittiwakes though (I just wouldn't have been prepared to go for the "Sure as I can be" certainty level).
Migrating flocks of Kittiwakes are not uncommon at this time of the year on the west coast.
Lat/Lng: 57.222082933351, -5.6745457649231
OS grid ref: NG782205