158 BIRDS IN LONDON 



are situated advantageously may be found in 

 the fact that three of the species which have 

 estabhshed colonies in London within the last 

 few years (wood-pigeon, moorhen, and dabchick) 

 first formed settlements here, and from this 

 centre have spread over the entire metropolis, 

 and now inhabit every park and open space 

 where the conditions are suited to their require- 

 ments. These three needed no encouragement : 

 the summer visitors do certainly need it, and at 

 Battersea, and in some other parks less than one 

 fourth the size of Hyde Park, they find it, and 

 are occasionally able to rear their young. Even 

 the old residents, the sedentary species once 

 common in the central parks, find it hard to 

 maintain their existence ; they have died or are 

 dying out. The missel-thrush, nuthatch, tree- 

 creeper, oxeye, spotted woodpecker, and others 

 vanished several years ago. The chaffinch was 

 reduced to a single pair within the last few 

 years ; this pair lingered on for a year or a little 

 over, then vanished. Last spring, 1897, a few 

 chafiinches returned, and their welcome song 

 was heard in Kensington Gardens until June. 

 Not a greenfinch is to be seen, the commonest 

 and most prolific garden bird in England, 



