212 BRITISH BIRDS. [vol. xni. 



danger itself which in time will call out the appropriate response 

 without the aid of the stimulus provided by the adults. 

 Similarly the protective response becomes transferred to the 

 danger calls of other individuals of the same or of different 

 species. When in danger the young tend to run in a direction 

 opposed to that taken by the adults, and thus the adults 

 are able to control indirectly the direction taken by the 

 young. Later the young learn to react appropriately to 

 the position and direction of movement of the danger 

 independently of the parents by acquiring spatial and other 

 references for themselves. They also learn to discriminate 

 among dangers and to modify their reactions accordingly 

 on a basis of experience of the different modes of reaction 

 of the adults to the same dangers. Thus running out of the 

 way of cattle and hiding up on the approach of a man or a 

 dog are in their discriminative aspect differential reactions 

 acquired from experience of the different behaviour of the 

 adults in the two situations. 



Under the conditions of daily observation the first associa- 

 tions of the chicks are formed with the human danger. Under 

 more natural conditions the first associations are probably 

 formed with food. By the 2nd week the relation of crouching 

 and free activity to the behaviour and calls of the adult is 

 perfected. The food signal and the offer of cover evoke an 

 immediate response. Dangers are recognized at a distance. 

 Hunger is associated with the local feeding ground. The 

 young try to induce the parents to leave the shingle (refuge) 

 to feed, by tapping the parent's bill or (5th week) by tapping 

 the ground before the parent, and if these fail by attempting 

 to lead the adults in the direction of the feeding grounds. In 

 the 3rd week certain signs are effectively associated with 

 the presence of food deeply buried in the soil. 



Learning is sensory rather than motor, inhibitory rather 

 than formative. The motor responses are racial or specific 

 characters which appear inevitably during progress towards 

 maturity. They undergo remodelling and precising through 

 the action of experience. But new forms of motor response 

 have not been observed. The motor reactions are innately 

 connected with parental behaviour from which they are 

 transferred to environmental stimuli, at first of a general 

 type, later of a more definite character. The sensory field 

 gradually widens simultaneously with the refinement of 

 sensory discrimination which in the Oystercatcher appears 

 mainly to be visual, auditory and tactual. Association 

 consists here in connecting the products of improving sensory 



