The elongated "Curlew-like" upper mandible on this young Herring Gull is getting longer and longer...and yet it doesn't seem to be affecting the bird's survival. I did not notice any deformity of the beak when ringing this gull as a chick on Jethou in June 2010. Interestingly though there is a second 1st summer Herring Gull, which is only a few ring numbers different, which also has an elongated upper mandible. I wonder if they are from the same nest, and it is a genetic deformity which has been passed to two of the offspring? (Because gull chicks do not stay in the nest, but hide in pebbles and vegetation close by, it is almost impossible to know which birds are siblings when we ring the chicks). In August 2010 I saw Herring Gull White 6.AP0 several times on Pembroke Beach, Guernsey (but made no comment about the upper mandible). I next saw the bird on 15 January 2011, when the mandible was noticeably elongated...so it has taken time to grow to the proportions shown in the photograph. Surely it cannot keep growing, but the end will get chipped/eroded soon? It will be interesting to follow this bird's progress!
Herring Gull White 6.AP0 with elongated upper mandible - Chouet Beach 27 April 2011 - PKV