342 THE HERON 



feathers are of one uniform, dull hue. From this we may gather that 

 the protective value of the coloration is not dependent on the precise 

 tint or pattern of the plumage, but on its general resemblance to the 

 surroundings, and one other factor the assumption of a peculiar 

 pose at just those critical moments when alone the coloration is of 

 vital importance. Then the part played by pose and pigment is 

 startling. Briefly, the bird, if alarmed, tilts up the body, and thrusts 

 the neck and head straight upwards, so that the tip of the beak points 

 skywards, and having assumed this attitude it remains as motionless 

 as the reeds surrounding it on all sides. Long lines of dark chesnut- 

 brown running down the front of the neck simulate the shadows 

 between the reeds, the lighter background and thick dark lines 

 simulate dead reed-stems. As a consequence, it is only by the merest 

 chance that the presence of the bird is detected, and even then 

 it is by no means easy, and after a close approach, to elicit any 

 sign of life. At times the body is held in a crouching position, and 

 the head drawn close down at the shoulders. Then woe betide 

 the man or beast who comes too near, for with a lightning speed the 

 long neck and dagger-like beak are shot upwards, and with terrible 

 effect. 



No observations seem to have been made, or at any rate recorded, 

 as to the part played by the peculiar erectile frill which, as we have 

 remarked, runs down each side of the neck and over the back of the 

 head. It is present in both sexes and in young birds, and, strictly 

 speaking, should be regarded as an ornament, a secondary sexual 

 character, originally a seasonal adornment of the male, but now per- 

 manent, and assumed with the juvenile plumage. It is quite possible 

 that it may be used, on occasion, as a terrifying agent, adding ferocity 

 to the bird's appearance, when endeavouring to repel enemies other 

 than man. 



That this frill may be used during the " courting " period, as in 

 the case of the great crested-grebe, wherein both sexes are in like 

 manner similarly adorned, is quite possible. But we unfortunately 



