VOL. xm.] THE OYSTERCATCHER. 211 



or possibly of alarm. Fear as shown by startled eyes and 

 open bill is apparent by the 12th day. On the next day a 

 definite sign of satisfaction is observed in sidewise waggling 

 of the tail after feeding. Precocious sexual activities appear 

 from the 4th week onwards as billing, the utterance of vocal 

 trills, and later as nuptial pursuits of other chicks or of the 

 parents. Rivalry for food appears as early as the end of 

 the 3rd day, but at this stage the presence of other chicks 

 probably has little to do with the behaviour. Curiosity or 

 alarm in response to invisible auditory stimuli even at 200 

 yards distance is very evident in the 5th week. The attitude 

 assumed is that described by Craig for Pigeons in alarm, and 

 it is also assumed by young Oystercatchers when the adults 

 are indulging in post-nuptial antics. As at these times the 

 young eventually hide or crouch, alarm is probably the real 

 affective correlate. 



Attention. — Attention is apparent on the ist day, but 

 objects as a whole are not recognized. Attention is attracted 

 by parts which are not welded into a whole by perception. 

 Thus the chick at first responds negatively to the human 

 eye. Towards the end of the ist day it is negative to the 

 hands as well, but it is still positive to the trouser leg, or a 

 large object moving away from it. By the 2nd day all parts 

 of the person are reacted to as being dangerous, but it is 

 doubtful if they form a connected whole for the chick before 

 the 3rd day. At the end of the ist week the chicks begin 

 to attend to the signs of food in the ground and to the appear- 

 ance of probings made by the adults. Attention of this 

 kind becomes increasingly important as the chick grows 

 older. At first attention quickly lapses : later it can be 

 maintained for 2-3 minutes. In the 2nd week dangers at 

 a distance are attended to and recognized, as well as auditory 

 stimuli such as the danger call of the Lapwing, while from 

 the 3rd week onwards the nuptial antics of the adults are 

 closely watched. 



Imitation. — The following instinct is a more potent factor 

 in nature than it appears to be in the laboratory. It is a 

 direct incentive to bathing, preening, probing, and to flight. 

 Its anticipatory value, however, is small. At the most it 

 hastens the appearance of motor activities which are shortly 

 due. But it serves a purpose in overcoming hesitation and 

 in making a motor act more immediately effective. 



Association. — The first reactions to danger are in reality 

 responses to the danger calls and actions of the parents. 

 Very early these reactions come to be associated with the 



