Vol. XVII 
1900 
Herrick, Care of Nest and Young. 103 
The cleaning of the nest and young is apparently instinctive 
with the adult bird, and so is also the care with which many 
avoid soiling 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. 1. Female Bluebird carrying food to young. Fig. 2. 
Female Bluebird leaving nest hole in act of cleaning nest. (Photo- 
graphed at a distance of 18 inches.) 
