ob"J BIBDS OF XOEFOLK. 



tlie reed or rotting pieces of" boulder," but wbeu the time 

 of liatchiag approaches the old bii-ds considerably enlarge 

 the base of the sti-ucture, adding dead stems of glad- 

 don till quite a floating raft is formed ; this, as in the 

 ease of the gi*eat-crested grebe p. 240), is evidently 

 intended as a resting-place for the voung, which other- 

 wise, the nests being only slightly above and quite sur- 

 rounded by the water, would hare no di-y sui-face to rest 

 upon. 



It is very rai'e to observe any signs of immaturity 

 about the breeding gulls. Occasionally one is seen 

 with a bai'red tail, the last mark of youth, but this is 

 decidedly exceptional : on the other hand, the bii'ds on 

 the coast are most fi*equently in immature plumage. 

 The appetite of the black-headed gull seems to recog- 

 nise very little distinction of food ; it has been seen 

 hawking for moths on a summer's evening, flying over 

 the grass like a swallow. Cockchafers, wii-eworms, 

 aquatic insects, frogs, mice, and even small bii'ds in 

 the nesting-season — probably captui'ed on their nests — 

 have been known to minister to its necessities. It 

 may be seen miles away, following the plough, doing 

 inestimable service to the fanner, and, strangest food of 

 all, in the year 1663, when great numbers of the young 

 perished from want of food, owing to the long continued 

 drought, ALr. Stevenson tells us ''the dead fed the 

 living, since the maggots from the bodies of the dead 

 nestlings formed a scanty provision for those hatched 

 later in the year." 



There is reason to beheve that the bulk of the black- 

 headed gulls which breed here pass south in the autumn. 

 'Sir. Stevenson says he has frequently distinguished the 

 harsh notes of this species, apparently in large numbers, 

 fonning part of the flocks of migrants passing over this 

 city on dark autumnal nights, but the place of these 

 wanderers is filled by others, probably aniving from 

 more northerly locahties, for this species is one of those 

 most commonly met with on our coast during the whole 

 year, even during the breeding season considerable 

 numbers of immature bii-ds frequent the shore, as it 

 rai-ely nests till it has assumed its foil plumage, which 

 requii-es two or perhaps three years to acquire. lu 



