BIRDS OF THE DISTRICT OF STAINES. 309 



unique and fascinating study to all ornithologists, and, although 

 much has been written of the bird, there are still many things 

 yet to be explained. 



Barn- Owl (Strix flammed) . — Of rare occurrence. 



Short-eared Owl (Asio accipitrinus) . — Exceedingly un- 

 common. 



Tawny Owl (Symium alaco) .—Has considerably increased of 

 late years. In early spring its calling may be heard every 

 evening quite close to the town. 



White-tailed Eagle (Haliaetus albicilla). — At Virginia Water 

 in 1876 (cf. Zool. 1902, p. 230). 



Sparrow-Hawk (Accipiter nisus). — Sparsely distributed, but if 

 only left alone I think it would soon become more numerous. 



Kestrel (Falco tinnunculus). — A decreasing species. Has 

 not been known to breed for many years now. 



Common Heron (Ardea cinerea). — There is a small heronry of 

 about fifteen nests at Virginia Water ; the number of nests is 

 always about the same. Although this spot is within a stone's 

 throw of the lake, the birds now fly daily several miles to the 

 Staines reservoirs, and spend the day standing on the sloping 

 concrete sides fishing. The reservoirs have been well stocked, 

 and teem with fish, so that the birds are probably well repaid 

 for the longer journey. 



Mute Swan (Cygnas olor). — There are plenty of these birds 

 on the river. As a rule they do not fly far, or at any great 

 height, so it is curious that one discovered the reservoirs, which 

 are two or three miles away from, and at a much greater eleva- 

 tion than, the reach frequented by this bird. Every morning it 

 would fly right over the houses and railway-station, and settle 

 on the waters of the reservoir, pass the day there, and return to 

 the river at dusk; and in a very short time two companions 

 joined in these expeditions. The object of this behaviour is not 

 clear, for the bird's chief food is the various weeds that grow in 

 the river, but owing to the depth of water such weeds are entirely 

 absent from the reservoir, and it would seem that these birds 

 must prefer an entirely fish diet. In the winter, when the river- 

 weeds have died down, the birds often come ashore, along the 

 banks and in the meadows, to eat fresh green grass. At breed- 

 ing-time the males fight fiercely if one intrudes on another's 



