238 Papers from the Marine Biological Laboratory at Tortngas. 



end of the first day the birds were able to stand fairly erect and to move 

 their heads with some freedom, following my pen-point with both head and 

 eyes when it was moved in front of their heads. When taken from the nest 

 and pnt npon the floor, the birds showed a marked tendency to shrink when 

 the shadow of the hand was thrown across the head. As I write with one 

 npon the table before me, it is pecking vigorously at my fingers. Pecked 

 once at a large spot on the table, then at its toe. They show no fear at 

 being handled. They can not swim at the end of the first day. They were 

 tried first in fresh water. No coordination of limbs was present. Head 

 could not be held up and birds began to sink rapidly. Water caused defeca- 

 tion in one case and disgorgement in another (they had been left with the 

 parent for 5 hours). The movements used in disgorgement were as 

 rhythmical and perfect almost as is the case with the adult. The birds 

 yawned a great deal (the same is true of adult noddies and sooties). This 

 reaction is quite different from that used in opening the beak for food. 

 While yawning they will not accept food. The note of the young noddy 

 is very dilferent from the hoarse, rattling sound of the adult. It is a soft, 

 liquid, slow, plaintive " querk-querk-querk." 



The huddling reaction^ is present the first clay. The birds all huddle 

 together after being separated. They lower their heads and attempt to 

 nestle under the bodies of their companions. .A.t the end of the first twelve 

 hours these birds are the superiors in the point of development of the 

 sooties, but the sooties very rapidly outstrip the noddies. 



All of these reactions which are present in the young bird on the first 

 day are of vital importance to them, with the possible exception of yawning 

 (even this reaction, apart from its possible value in respiration, may be of 

 value in strengthening the musculature of the jaws, etc.). It is abso- 

 lutely imperative for them to have the free use of the head and eyes and 

 to be able to stand erect and to peck during the first day. The feeding 

 parent on returning alights near the young bird, puts down its beak, and suc- 

 cessively touches and taps the beak of the young bird, then its part of the re- 

 action is at an end, provided by successive disgorgements it keeps its beak 

 and throat filled with small minnows. The young bird must stand up and 

 strike the beak of the parent until the parent opens its beak sufficiently wide 

 to admit the beak of the young bird. When the fish in the mouth of the 

 parent come into contact with the buccal cavity of the young, the swallow- 

 ing reflex follows perfectly. The pecking of the young birds at the objects 

 in their surroundings is not at first a pecking in the sense that the little 

 chick pecks. It is rather a striking reflex. By means of it the young 

 bird gains access to the mouth and throat of the parent. 



The huddling reaction mentioned above is of value by reason of the 

 fact that it gains for the young bird the protection of the parents' body 

 from the cold of the northeast trade winds which set in at night. It is not a 

 protective reaction in the sense of hiding from an enemv. 



Second day: 



The young noddies were kept day and night in a box which was covered 

 by a cloth. They are extremely quiet all the time. At first they are small 

 eaters, consuming rarely more than three minnows of small size at a feed- 



' Not the true gregarious reaction in all probability. It was the normal mode of 

 reaction to the parent. 



