BIRD LIVERIES AND THEIR MEANING. 31 



— heigho, as if in obedience to the magician's 

 wand our bird has vanished ; what appears to be 

 a bundle of rags remains in its place. 



The colouration of some of the most sombre 

 plumaged birds we are apt to regard as instances 

 of the "dull but usefur' order: and to reflect, 

 with the eye of a careful house-wife, on its good 

 wearing properties : and here we generally leave 

 it. As a matter pf fact, it is fraught with a 

 deep significance. It certainly affords us some 

 admirable illustrations of protective colouration. 

 Take the case of the night -jar or goatsucker, 

 the bird which shares with the bat and the owl, 

 the charming twilight evening hours of our rural 

 England. Its exquisitely mottled plumage of 

 grey and brown so perfectly harmonises with the 

 bough along, and not across which it rests, or 

 when sitting on its eggs, with bits of bark and 

 stone strewn about the ground, that it be- 

 comes invisible, and can only be detected by 

 the merest accident. Again, in the "common" 

 bittern of our Islands — alas ! no longer common 

 — we have a splendid instance of protective 

 colouration, aided, as in other cases, by posturing 

 on the part of the bird. The general tone of its 

 plumage is buff, streaked with black in such a 

 way as to simulate the colour of the dried stems 

 of the reed-beds which it frequents, and the 

 shadows between the stalks. On alarm, the bird 

 straightens itself out so that the head, neck and 

 spine form one vertical line, pointing skywards. 

 Thus posed, it remains absolutely still till danger 

 is past : the chances of detection amid such 

 surroundings being infinitely remote. How 



