COURTSHIP AND SEX 177 



§ 2. Modes of Courtship Summarised 



A. Appeals to Sense of Hearing : — 



Song, twittering, cooing, crowing, calling, flapping 

 of wings. 



B. Appeals to Sense of Sight : — 



Display of plumage and of skin-ornaments such as 



wattles. 

 Display of movements showing agility and grace, in 



strutting, parading, fluttering, flying. 

 Often repeated rhythmical movements, e.g. bowing, 



curtseying, dancing; " suggestive " movements, as 



when the male jumps over the female (pigeons). 



C. Appeals to sense of touch : — 



E.g. when male chough strokes the head of the female 

 with his bill, when male pigeon presses his neck 

 over that of his desired mate, when male pigeon 

 receives in his open mouth the bill of the female. 



D. Chasing the female on the ground or in the air, or 



driving her towards the nest. 



E. Varied subtler modes, some of which may have a symbolic 



significance, e.g. when the Great Crested Grebes offer 

 water-weed to one another. 



§ 3. The Mating Behaviour of Pigeons 



The prolonged observations made by the late Professor 

 CO. Whitman (191 9) on various kinds of domestic pigeon 

 and wild dove yielded many very interesting results. 



The impulse to sexual activity is primarily from within, 

 arising for the most part automatically, but the fire is fanned 

 by the mutual influence of the sexes, and it may be intensified 

 or depressed by extrinsic influences such as diet and weather. 



The impulses arise synchronously in the two sexes, but 

 it is normal for the male to take the initiative in beginning 

 the cycle. Modifications of the usual behaviour will result 

 if the two birds are very different in their state of readiness ; 



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