BIRDS IN LONDON 337 



growing sicklier and more decayed. It is doubtful, for 

 example, whether the spotted flycatcher has nested in Hyde 

 Park or Kensington Gardens for some years past, though 

 it did so until quite recently ; and the same process of dimin- 

 ution or disappearance is noticeable in the case of the summer 

 migrants almost everywhere in the metropolitan area. Birds 

 which visit London in winter, on the other hand, have grown 

 far more numerous ; and in some cases they are not only 

 winter visitors, but residents all the year round. The regular 

 arrival of large flocks of black-headed gulls in autumn dates 

 from the great frost of 1895; and the increase of wood- 

 pigeons, with the remarkable change in their habits which 

 town life produces, has been more and more noticeable 

 during the same period. So it comes about that in London 

 the ordinary contrast between the seasons is precisely 

 inverted. Londoners see the first gulls return to the river 

 in autumn with the same sense of anticipative pleasure that 

 countrymen feel when they see the first swallow in spring. 

 The gulls begin to return to London in considerable numbers 

 about the third week in October, though a few immature or 

 unmated birds may be seen as stragglers in August, or even 

 earlier. Their date of migration to their winter home is thus 

 about a week later than that of the swallow and many other 

 summer migrants ; but it is part of the same great movement. 

 By November they have fairly settled down for the winter ; 

 and they depart about the third week in March, or a little 

 earlier in a very open season, leaving a few stragglers behind 

 them. Their numbers vary a good deal according to the 

 weather; after hard frosts or violent gales, the flocks 

 wheeling and screaming at the parapet of the Thames 

 Embankment are twice as numerous, and twice as hungry, 

 as in spells of calm. They feed to a great extent on what 

 they can find on the surface of the river and its foreshores, 



