BIRDS IN LONDON 343 



along the riverside at Chiswick Mall or Strand-on-the- Green. 

 Unable to rest on the water, like the gulls, they are less at 

 home on the river between Westminster and St. Paul's ; the 

 noise of the traffic and the absence of any convenient resting- 

 place at high water keeps them restless and timorous, and 

 they flit uneasily over the plane-trees and across the river 

 with an anxious cry. Often this familiar call first draws 

 attention to their slender forms as they waver across the 

 wide brown channel of the river. There is a strange contrast 

 between these London scenes and the shores of the mountain 

 torrents where they are familiar in the summer half of the 

 year. 



Brown owls are chiefly winter visitors to the more central 

 parts of London, though one or two pairs may possibly still 

 remain to breed. They are sometimes heard in spring and 

 summer within a mile of St. Paul's ; but these may be unmated 

 birds. For many years in succession a large hollow elm in 

 the northern part of Kensington Gardens was tenanted every 

 winter by a brown owl, which arrived in autumn and left 

 again in spring. The ground beneath the tree was littered 

 with numerous undigested pellets, each of which contained 

 the bones and feathers of a sparrow neatly packed up. For 

 the last few seasons there has been no sign of this tree being 

 tenanted ; but owls are still often to be heard in Kensington 

 Gardens and Holland Park, and are occasionally seen perched 

 among the branches by day. Brown owls feed chiefly on 

 small birds, and thus find a plentiful source of subsistence in 

 the London sparrow-flocks ; but white or barn owls live 

 chiefly on mice and young rats, caught in the open, and are 

 therefore seldom seen or heard in the central parts of London, 

 though they are not very uncommon in the suburbs. The 

 peril of owls in the dark may be one reason why London 

 sparrows are fond of roosting in trees which are lit up all 



