I walked the Cleveland Way along the clifftops from Whitby to Robin Hood's Bay in Yorkshire on the 1st of June. Near Whitestone Point and Whitby Lighthouse, I spent some time watching the kittiwake colony. Low down, near the base of the cliffs, I saw, at intervals, two or three alcids flying rapidly out to sea, and then returning to the cliffs just as rapidly. From my viewing angle atop the cliffs, I was never able to see any of them land, so all of my observations were of the birds in flight, at quite a distance. I wasn't able to get a clear look at the birds' bills at any point. I managed a couple of photos which at least show that they must have been either Razorbills or Guillemots, but since I have no experience with this particular ID problem, I have no idea if it's possible to determine the species from these pictures with any high degree of probability. I'm happy to leave these birds unidentified to species if there's no way to tell them apart, but the Collins bird guide does suggest that such an ID is at least doable, so I thought I'd ask. Note that the two photos were taken several minutes apart and may well show two different individuals.