GLAUCOUS GULL. 685 



p. 36). Another strong migration took place on I7th October 

 1898, with a north-east gale. In spring also this gull is 

 noticed moving northward at the same time as the Lesser 

 Black-back is observed on passage towards the nesting grounds, 

 although, as is well known, there is no breeding station of this 

 bird on the east coast. The late J. Cordeaux's remarks as to 

 its former nesting at Flamborough (Zool. 1864, p. 9247) are 

 not supported by any evidence that I am aware of. 



The Great Black-back is not so common as some others 

 of its genus away from the coast, but has been met with in 

 the south and centre of the West Riding, chiefly on sheets of 

 fresh water, and occasionally occurs in the valleys of the Aire, 

 Nidd, Ure, Swale, and Tees. 



Individuals vary greatly in size ; I obtained an adult 

 female on I2th November 1875, which measured thirty-one 

 inches from bill to tail, and whose wings extended to the 

 width of six feet. George Mussell, the Middlesbrough 

 taxidermist, is of opinion that, as this bird advances in age, 

 the pink tinge of the legs and feet becomes fainter until those 

 parts are almost colourless ; an example examined on 6th 

 January 1902, had the legs and feet nearly white, while the 

 spots on the head and neck were very faint ; this, according 

 to the above-mentioned theory, indicates great age. 



Local names : Black-back, in general use ; Black and 

 White Gull ; Saddleback, at Redcar ; Black-backed Hannock, 

 at Bridlington, and Wagel Gull, applied to the immature bird. 



GLAUCOUS GULL. 

 Larus glaucus (Faber). 



Winter visitant on the coast ; immature birds are met with every 

 season, but not numerously, except in very severe weather ; mature 

 specimens are rarer. 



The first allusion to this bird in the county is found in 

 Thomas Allis's Report of 1844, thus : 



