230 BIRD BEHAVIOUR 



that it does not interfere with the gaze, and is 

 hardly noticed by the onlooker. The Dipper, or 

 Water-Ouzel, also blinks the upper eyelid like an 

 Owl ; the reason of this seems obscure, since other 

 birds that hunt under water do not do so. 



Nor, as far as that goes, do all Owls hunt at 

 night ; many, such as the Snow Owl, Hawk-Owl, 

 Short-eared Owl, and Burrowing Owl and some 

 others, hunting either by day or by night, while 

 the Little Owl and Indian Little Owl {Athene 

 noctua and A. bramd) come out while it is still 

 daylight ; in India I used to notice the latter out 

 at about five o'clock in Dehra Dun, while in Cal- 

 cutta they did not show themselves till nightfall, 

 no doubt owing to the hostility of the numerous 

 Crows, for I have seen a homing Crow swoop 

 at an Owl which had appeared a little too soon. 



There are also some Nightjars which hunt by 

 day, such as the American Night-Hawk (Chordeiles 

 fofetue), which is often abroad high in the air in 

 bright sunlight. Woodcocks and Snipe, which are 

 usually night-birds, may also feed by day. 



Conversely, many of the birds which have no 

 speciail adaptation for night vision often fly and 

 feed at night, such as many members of the EJuck 

 and Plover tribes, especially the common Lapwing 

 and Mandarin Duck, whose unusually large eyes 

 may, however, be an adaptation to these habits. 

 Certainly the last-named bird, in spite of his gay 

 colours — such being almost unknown in true noc- 

 turnal birds, which are sombre like mammals — ^is, 



