THE BLACKHEADED-GULL 139 



presence not only of the foraging males, but of a large number of 

 immature birds born in the previous summer, and easily identified 

 by the flecks on the wing, the black rim to the tail, and the absence 

 of a brown hood. 1 These came each evening to roost, and departed 

 in the morning. They distributed themselves all over the gullery, 

 possibly returning each to its birthplace. 



The number of the non-breeding gulls is not limited to these 

 immature birds, but to what extent, if at all, non-breeding adults 

 are to be found on the breeding-ground itself I do not know. Some 

 are to be seen on the coast throughout the summer. 2 The most 

 remarkable example is provided by a bird which spent the whole 

 summer by itself on the South Walsham Broad, in Norfolk, where 

 its solitary white figure was a striking object seen flying amid the 

 deep green foliage round the lake. 



The gulls that pair have, like other species, a love-display. This 

 I saw at Ravenglass on May 16, when the eggs were already hatching. 

 The performance took place away from the breeding-ground on the 

 mud-flats in front of the village. One of the pair, which I judged 

 from her more restrained demeanour to be the female, kept her beak 

 bent vertically downward. Otherwise her attitude did not depart 

 from the usual. Her mate had his beak bent downward, his tail 

 fanned and somewhat deflected, his wings hanging, and his plumage 

 puffed out. He presented a very queer object indeed. Like the 

 female, he kept moving about with precise and formal little steps. 

 Both held themselves stiffly, and looked as if they were performing a 

 ritual. I did not see them face each other ; they walked one after 

 the other bowing, and sometimes the cock turned round so that they 

 bowed in opposite directions. The performance was accompanied by 

 a loud discordant note, uttered by one or possibly both. It was 

 continued for several minutes. 



1 At Scoulton I saw none of these immature birds with a brown hood except one, which 

 had, however, the forehead white. At Ravenglass in mid-May (16th to 21st) there were a few 

 abont the gullery in the daytime. These had the hood more or less brown. One of them was 

 actually sitting on eggs, but it was the only one I saw thus engaged. 



2 Nelson, Birds of Yorkshire, p. 070. 



