Is this a Great Skua?

QCan you please tell me what bird this is? It was taken on 31 July on Tiree. Is it a Great Skua? Michael Douglas

AIdentifying birds from silhouettes is fraught with all sorts of difficulties due to the lack of the usual visual features. However, that being said we think that this could indeed be a Great Skua, or ‘Bonxie’ as they are often called. The shape is ‘right’, although we’d have liked some hint of those pale wing flashes to make us more certain. Of course, it could equally be a gull, and the lack of wing flashes (even when we severely adjusted the picture in Photoshop), as well as stripiness at the tail, both suggest that it is a young gull rather than a skua.