xvii. 7 RITUAL FEEDING 5°i 



teristic of all bird displays that they involve sights and actions that 

 have a peculiar and exaggerated quality for us and probably also for 

 the partner (Figs. 304, 305). Watching the effects of such appearances 

 on the female one has the impression that this vision acts as it were as a 

 key or 'releaser', opening in her the appropriate course of behaviour. 

 Under its influence she acts as if 'mechanically', moving towards the 

 male and adopting the receptive position, while his display activity 

 passes over into that of mounting and coition. This sort of behaviour 

 we have seen elsewhere in bird life; there must be in the nervous 



Fig. 305. Display of the pheasant, Centrocercus. i. Beginning of inflation. 



2. Complete display with cervical air-sacs inflated. (From Stresemann, 



after Horsfall.) 



organization a receptive matrix ('the lock') ready to be actuated by the 

 appropriate 'key', which may be the display of structures as bizarre 

 as the wattles and tippets of a turkey. 



Many displays are modified versions of everyday actions of the 

 birds and some at least of these seem to be symbolic. Thus, in many 

 birds courtship and coition include ritual feeding of the female by the 

 male. Involved in this is a reversion by the female to an infantile con- 

 dition. She may beg for food, often with actions similar to those she 

 used as a nestling. The prime significance of this feeding is not in the 

 nourishment provided but, in many cases at least, in the fact that it is 

 the male who provides it. This is proved by the fact that the female 

 (robin, for instance) will not feed herself when food is all around, but 

 will beg the male to give it to her. Female herring gulls bringing back 

 fish may even beg to be fed by the male, who has not left the rock! 

 There are, of course, many cases of practical feeding of the sitting 

 female by the male, but it is possible that these have been derived from 

 the ritual feeding, rather than vice versa. 



