At the time of our visit to Stackpole Head in early May the guillemots were gathering ready for the breeding season. This species does not build a nest but lays a single pyriform (pear shaped) egg directly onto the rock ledge. The advantage of an unusually pointed egg is that, if it rolls, it does so in a tight circle and is therefore less likely to fall off the ledge.
In the southern UK the first eggs are laid in mid-May. In the north early June is more typical. Guillemots are communal nesters (and feeders, as the second photograph shows.
Incidentally, the location of the guillemots in the first photograph can just be discerned on the lower right hand edge of the top photograph of the previous post.
photo 1 © T. Boughen Camera: Nikon P900
photo 2 © T. Boughen Camera: Nikon Z 5
