Vol. xviin 

 1900 J 



Herrick, Care of Nest and Young. 



The cleaning of the nest and young is apparently instinctive 

 with the adult bird, and so is also the care with which many 

 avoid soihng the ground and foliage about their nesting sites. 

 They apparently have no choice in these matters, but act because 

 they must. . As to eating the excrement, however, it is not so 

 clear. We need many more observations on different individuals 

 before a decision can be reached. If it should be proved that 

 in the Robin, for instance, some individuals never eat the excre- 

 ment while others do, as we know, we might regard the action 

 as an acquired habit. When the pellicle breaks in the mouth, 

 an accident which I have seen happen in the case of a Robin, 

 the bird must swallow some part in order to get rid of it. More- 

 over, since digestion in the young is an imperfect process, the 

 substance may serve as a kind of predigested or partially digested 

 food, which might be acceptable to the old birds in times of 

 stress, as in prolonged and heavy storms when food is not easy 

 to procure. 



The fact that the Robin removes a part of the excrement from 

 the nest but devours the remainder would seem to imply either 

 that it discriminates what is suited for food, which is improbable, 

 or that this action is a habit not yet fully established, and cer- 

 tainly not ingrained. 



Descriptions of Photographs. 



Plate II, Fig. 1. Female Robin inspecting nest. Fig. 2. Male Robin 

 cleaning nest. (In act of swallowing excrement removed from nest; 

 the adherent dead grass is from nest lining.) 



Plate III, Fig. i. Female Bluebird carrying food to young. Fig. 2. 

 Female Bluebird leaving nest hole in act of cleaning nest. (Photo- 

 graphed at a distance of i8 inches.) 



Auk, XVII, April, 1900, vy>.io»~l03. 



