Tlie Behavior of Noddy and Sooty Terns. 



25' 



become. The jerky, uneven reactions of the adult sooty are already showing 

 themselves in the early behavior of the young sooty. 



THE BEHAVIOR OF THE NODDIES IN LEARNING A MAZE. 



The same routine of learning the maze was adopted in the case of the 

 noddies as was described above for the sooties. The noddies, however, were 

 19 days of age before they were comparable as regards development with 

 the sooties, 15 days of age. 



Table 4 and the graph constructed from it (fig. 4) show the time-records 

 and the characteristic features of the formation of this association. 



Table 4. — Individual and average time records of three noddies in learning Porter's 

 simple maze in minutes and decimals of minutes. 



The noddy is very much slower in learning the maze than the sooty : 

 (i) because of less general activity, and (2) because of longer periods of 

 standing. Mention has already been made of the habit of the adult noddies 

 of standing motionless for hours upon the top of any object which projects 

 from the surface of the water. When the young noddy is placed at the 

 unfamiliar position at H, he shows the tendency to react in this way to a 

 marked degree. Although I exerted every care to keep the food conditions 

 constant, I found that the first few trials of the noddy were quite unsatis- 

 factory. So persistently would they stand in their tracks at H tliat I finally 

 had to arouse them by tapping on the wall. The first three trials recorded 

 above are valueless for this reason. From the fourth trial on, however, the 

 records were made in the usual way. The errors are not markedly different 

 in point of numbers or in kind from those of the sooty. The above curve, 

 with the limitation above noted, is quite characteristic. It will be observed 

 that 13 trials were necessary to bring the curve down to the point repre- 

 senting one minute of time. This point was reached by the sooty at tlie 

 eighth trial. This brings out the general fact which I have noted else- 

 where,^ that the young sooty is much more active than the young noddy. 



• See p. 243. 



