Tlic Behavior of Noddy and Sooty 'ferns. 227 



alighted upon the pan in its new position and sat down on egg. I then 

 scared tlie bird away, 5 successive times, to see if it would alight imme- 

 diately upon the pan. Each time on returning the bird alighted at the old 

 ground position and proceeded from this point to the new position of the nest. 



I then put the pan back in its old position. Bird returned and aHghted 

 on pan immediately. In this position I then raised the pan to a height of 

 200 cm. This raised the nest well up above any of the surrounding bushes. 

 This did not cause the bird the slightest disturbance. I forced it to make 

 three or four adjustments to the nest in immediate succession. It made 

 them all with equal precision. 



I continued my experiments on this bird in a similar way for several 

 days and by repeatedly moving the nest now to the east, now to the west, 

 etc., I succeeded in getting the bird to the point where it would immediately 

 adjust to the nest regardless of its position.' 



.\s was the case with the noddy, I found that the nest environment could 

 be markedly altered without the bird's being disturbed in the slightest so 

 long as the position of the nest was not disturbed. 



SUMMARY. 

 In the case of both the noddy and the sooty, the nest locality is the im- 

 portant factor, the nest itself being reacted to by virtue of its location within 

 this locality. Since environment can be greatly changed without disturbing 

 the bird's accurate adjustment to the nest, it is evident that if the adjust- 

 ment is made in terms of visual data the visual environment which serves 

 as the stimulus must be complex and have a wide extension. I am not pre- 

 pared to admit from the above experiments that adjustment takes place in 

 terms of vision alone. 



SOME EXPERIMENTS ON DISTANT ORIENTATION. 



In the present connection, I shall not take up in detail the various theories 

 concerning the factors entering into distant orientation. Anyone familiar 

 with the literature on the subject knows that the facts, as well as the theories, 

 are in a chaotic state. I wish in the present instance to present a few facts 

 bearing upon the subject. It is generally supposed that the homing pigeon 

 possesses the function of orienting itself from a distance in a higher degree 

 than any other animal. It is also supposed that even in the case of the 

 pigeon training is necessary in order to get the bird to return to its home 

 from a distance. The method^ usually adopted is, first, to allow the bird to 

 get thoroughly habituated to its cote; then at successive trials the bird is 

 allowed to return to its nest from distances beginning at 0.125 mile, then 



'These tests are all confined to a radius of some 4 to 5 meters. I had intended 

 carrying the test further to see if I could force the establishment of so strong an 

 association that I could move nest from one part of island tn another, but a storm 

 which continued for several days made it impossible to continue the work. 



"Hodge: Method of Homing Pigeons; Popular Science Monthly, .■\pril, 1894, 

 pp. 758-776- 



