Alas, Poor Fulmarus glacialis...

Half a lifetime of beachcombing has left me with a box full of artefacts picked up from the strandline, including a collection of seabird skulls. I know that's a little weird (as my wife often points out) but these are fascinating pieces of evolutionary architecture. What strikes you immediately, when you first pick them up, is the combination of lightness and strength. The structure is pared down to the absolute minimum that's consistent with their function. Then there are those massive eye sockets, testament to the important of acute vision in these marine scavengers and predators. And the beak. The example above, identfied by Nyctalus, is a fulmar Fulmarus glacialis. The functional part of the beak - the buff-coloured section with that wicked hooked tip that probably hacked at innumerable food items during the bird's lifetime - is made of keratin, the same protein that forms our fingernails. In the dead bird it simply slides off the jaws and the lower beak has been lost in this specimen, while partial decay of the keratin in the upper beak has accentuated the hook at the tip, which is made of thicker, tougher keratin.

There are times when a bird's bill looks decidedly dangerous and you can't help wondering whether that glint in this gull's eye suggests that it's considering the possibility of tackling larger prey....

The second skull, above, belongs to a guillemot and in this one the keratin beak is still present on both upper and lower mandibles. Notice how, in the view from above, the upper beak is slightly curved to the right. Minor deformities are apparently quite common in birds' beaks. In this species the slim, streamlined head, adapted for diving, is a distinctive feature.