Hi Alan and Malcom, for the static shots I used my 500mm f/4, however with the bird in flight shots, I found the birds to be too close and fast in order to find them in the viewfinder and track using the 500mm. For these shots I used my 70-200mm which proved to be quite versatile, especially for the Artic Terns.
If you go to Inner Farne be sure to take a hat, the Terns dive bomb you and peck at your head, and also show what they think of you by messing on your head.
Gordon