72 BRITISH BIRDS. WITH THEIR NESTS AND EGGS. 



dark band on the tail vanishes. In the second spring the bird is preparing to 

 mate, and puts on its nuptial dress ; but for some years the brown on 

 the primaries may still be visible, indeed it may be four or five years before 

 they attain the full whiteness of the outer primaries, which characterizes the adult. 

 The brown hood of the breeding bird appears, according to Saunders, as a dark 

 line gradually running " from each ear-patch across the head ; later a similar and 

 parallel line grows up from the eyes, so that the head appears to have two narrow 

 bands of dusky grey ; then the dark feathers increase between, and lastly they 

 come as in front, till the base of the bill is reached." Saunders and others state 

 that the hood appears by a pigment change in the feathers and not by their being 

 truly moulted. This is denied by Mr. Tait, who observed birds in Portugal 

 in all stages of changing, from the white to the black feathers, and found 

 new ones to be springing up already black in their sheaths among the white 

 feathers. It is probable that both observers are correct ; for it may be that 

 in young birds, which are assuming their hood for the first time, the dark feathers 

 may come in new ; but in older birds the hood may be assumed by a pigment 

 change in the feathers only. It is to be remarked, however, that, in other birds, 

 where the main change is one of pigment, there do come in, as the present 

 writer has observed, a few by true moult as well. After the birds have reared their 

 brood, there then commences the true moult of the year, the result of which is 

 the Gull's winter dress, in which the dark hood has entirely disappeared, leaving 

 the head white, except for a grey patch on the ear-coverts and one in front of 

 the eye ; while the rosy tint of the breast is much fainter. 



On the completion of their parental duties, the Black-headed Gulls leave their 

 breeding places and move towards the coast, accompanied by the young birds. 

 Later in the season many of them migrate further south, large numbers, however, 

 spend the winter with us, however severe it may be. The present writers will 

 not soon forget the interesting sight which they were fortunate to witness during 

 the severe frost of February and March, 1895, when Black-headed Gulls, young 

 and old, were in thousands on the Thames, between the London bridges ; now 

 flying in circles, with noisy cries, on the look out for food thrown to them, or 

 resting on the blocks of floating ice which were being carried down by the tide. 

 "This unusual sight was viewed," as recorded in the "Field" of that date, "by 

 crowds of people, who forgot the cold in the fascination of watching these birds, 

 among which numbers of Terns, Kittiwakes, and Herring Gulls were associated. 

 Not only on the Thames but on the ponds in the various parks, where the water 

 was kept open purposely to allow the water-fowl there domesticated to feed, all 

 these birds congregated to the great delight of thousands of Londoners, to many 



