312 



The Bird 



to deposit an egg. A few other instances are known, as 

 where a fierce, bird-kiUing hawk resembles a harmless, 



insectivorous species, 

 perhaps by this decep- 

 tion deluding small 

 birds. 



Mam' of the plovers 

 have one, or even two, 

 bands of black encir- 

 cling the neck or 

 breast, and in the 

 Crook-billed Plover of 

 New Zealand there is 

 a most interesting mod- 

 ification of this ap- 

 parent ornament. This 

 bird feeds by running 

 rapidly around boulders 

 and inserting its crook- 

 ed bill beneath them 

 to obtain the insects 

 which compose its diet. 

 The pectoral ring of 

 black, instead of being complete, is said to be often less 

 developed on the left-hand side. Buller accounts for this 

 fact by arguing that that side of the bird is much more 

 exposed to danger, as it continually scurries about the boul- 

 ders, keeping always to the right, and thus the side next 

 to the stone needs no protective colouring; and so we 

 find this one-sided development of the band. How much, 



Fig. 249. 



-Ciyrfalcon. Aggressive coloration 

 in an Arctic Hawii. 



