Tuesday, February 23, 2010

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.

6 comments:

  1. Obvious when pointed out but not a fact I'd registered before. Thanks again. What are their feathers made of? Have always assumed in mammals that hair and claws were keratin.

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  2. These are beautiful skulls Phil. I find my self rather envious! I just wanted you to know that I have included a piece from your Ivy Flower piece ( the excellently named Last Chance saloon ) on my blog today. Have been drawing the Ivy Bee.. you have told me much about ivy I did not know! Thankyou.

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  3. Hi Adrian, the feathers are keratin too. useful stuff.

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  4. I agree Valerie, interesting but slightly macabre objects. Thanks for quoting my blog, and for the compliment in your post. Much appreciated. Kind regards, Phil

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  5. Great post Phil - skulls are fascinating. We must compare collections one day (or get a life maybe!). The lighting you've got on them is really effective and clearly shows the indentations on the top above the eyes where the salt glands sit. This inspired me to ponder some more on this - see my post at (http://standandstare-nyctalus.blogspot.com/2010/03/salt-with-everything.html)

    (I wonder - could the top one be a fulmar do you think?)

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  6. Now you come to mention it, Nyctalus, it could be a fulmar. The sloping profile of the forehead is herring gull-like but that beak tip is very strongly hooked... I thoughout it might be like that because of the way the keratin from the rest of the beak had decayed, but I think you may be right....

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