By the path around Handa, left there by a gull or skua. As with Guillemot eggs [[2311711]] they are strongly pear-shaped. Not the most efficient shape for maximising the volume or strength of the egg, but it means they roll in a circle and are therefore less likely to fall off their ledge.
Uploaded to Geograph by Hugh Venables on 9 June 2010
Photo © Hugh Venables, 9 June 2010. Licensed for reuse under this Creative Commons licence