his impressive large, pale gull was uncommon on our visit. Four subspecies are usually recognized. This is L. h. pallidissimus which breeds from the Taymyr Peninsula east to the Bering Sea and winters from northwest China east to Japan. It is the largest, biggest billed, and palest subspecies. This is an immature. Note bicolored bill and short wing-tip projection beyond the tail, decidedly less than length of bill. This can help distinguish adults from the similar but much smaller nominate Iceland Gull (L. g. glaucoides). Canon PowerShot SX60.
References:
Burger, J., Gochfeld, M. & Garcia, E.F.J. (2019). Glaucous Gull (Larus hyperboreus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/53979 on 18 March 2019).
Howell, S.N.G. and Dunn, J. (2007) A Reference Guide to the Gulls of the Americas. Peterson Field Guides, New York.
Malling Olsen, K. & Larsson, H. (2003) Gulls of Europe, Asia and North America. Christopher Helm, London.
Weiser, E. and H. G. Gilchrist (2012). Glaucous Gull (Larus hyperboreus), version 2.0. In The Birds of North America (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.573