66 BEHAVIOR OF PIGEONS. 



desire and energy on the part of the stronger bird. The second one does not satisfy the old 

 bird and is more and more neglected and in the end it becomes a dwarf bird, or it may die. 



On the question as to the part played by intelligence hi these cases, I may say that it 

 does not seem to me that the birds exercise intelligence; they simply act in accord with their 

 feelings. They appear to be very fond of the young birds, but their fondness for the 

 young is all determined by their feelings, or desire for relief. The moment they get over 

 their desire to feed they also get over their fondness for the young. If the eggs do not 

 hatch they have a desire to feed, but it is not so strong as to lead to bad results and they 

 soon outgrow it; it does not then make them sick. In those cases, however, where parents 

 really get started in feeding the young, the need to feed is most pressing; and if the young 

 die in two or three days after hatching, then the old birds are not only frequently made 

 sick as a result of not being able to feed, but frequently sick to death. 



The special secretions in the pigeon's crop seems to be stimulated in part by the sight 

 of the young and the amount of stimulation, or rather the amount of food which the parents 

 want to relieve themselves of, and it rapidly increases in amount during the days which 

 follow the beginning of feeding. If they do not begin actual feeding they get over it, but 

 if they once get started it is necessary to go on; otherwise they suffer. 



I have noticed in pigeons that the "weak are neglected" and the strong favored. This 

 is seen in the feeding as noted above. To get the full benefit of the parent's ability to feed 

 the young must push, squeal, and flap its wings and all this with vigor. The moment 

 these acts are not well performed, the parent's exertion dwindles for lack of stimulus. 



The feeding process is performed at least in many cases purely to get relief. The 

 old bird gives "milk," and at intervals this secretion must be thrown out. I have seen a 

 parent try to induce young to feed when the latter had no desire, having been well filled 

 by the other parent. The old bird gets into the nest and calls; if there is no response it 

 takes hold of the beak of the young and begins to pump vigorously. If the young die, 

 or if they are taken away, one may see after 6 to 10 hours how eager the parents are to 

 relieve themselves of the food reserved for the young. They are ready to feed anything 

 that will put its beak into their mouths; they will often return to weaned young (crested 

 pigeons) and feed them for a second time. They will try to feed an adult bird if that bird's 

 beak is only held in their mouth, and held low enough to simulate young in the nest. 



On the other hand, the old birds will often try to feed when they have nothing to give, 

 e. g., when young are given to them before the regular time for hatching has come. Thus 

 the act is performed sometimes for relief, sometimes in answer to the teasing of a hungry 

 young. 



The theory that the act was primarily one for relief from too much or from indiges- 

 tible food, and secondarily turned to use in feeding, has one great difficulty, namely, to 

 account for the "milk." I do not think that could have been at first a product of a use- 

 less nature, like ejected food. It is something that has probably been developed in con- 

 junction with the feeding. The dove's method of feeding occurs also in some other birds. 1 



As the young get larger, their feeding becomes for the parent more and more of a dread, 

 as they are ravenous and push with all their strength to get the food. The old bird becomes 

 wary and makes haste to finish quickly and retire, going out of the cot often before it has 

 full relief. It then continues to call, but hesitates to go in. The young stand at the hole 

 and squeal. The appearance is as if the old bird wanted to entice the young outside. 

 Later the old one grows still more cautious and the young venture out and are fed. The 

 next time they go out quicker and the old bird retreats. It then looks as if the old bird 

 wanted to teach the young to fly. It is evident, however, that this is no thought-out art, 



1 Lucas states (Mental Traits of the Pribilof Fur Seal, V, 1899), that the young of the fur seal was fed by the 

 mother for her own relief. 



