222 
FRANCIS H. HERRICK 
constancy. With an abundant food-supply the rate of feeding 
is determined to a considerable degree by the weather, and seems 
to be most rapid on hot clear days. In very bad weather, as in 
heavy rains, feeding stops entirely, when it is replaced by brood- 
ing, which in one recorded instance (table 5) lasted in this cuckoo, 
one hour, and thirty-eight minutes. 
The rate of feeding in 125 observed cases at nests Nos. 1 and 3 
covering a period of 53 hours, was once every 25 minutes, but this 
is undoubtedly below the normal rate, and such figures have no 
significance unless the variables are known. At nest no. 1 the 
rate of feeding began to fall the moment the first bird escaped 
to the bush. The highest feeding rate for an entire day (table 
5, third day,) once every 4 minutes, is of more interest, since 
such frequency is only observed in this cuckoo when fear is in 
abeyance, food abundant, weather favorable, and there are no 
young in the bush to divert the attentions of the parents from those 
at the nest. 
F. Intermittent brooding and behavior of cuckoo in rain 
The regular brooding instinct, which begins when there are 
eggs, and reaches a climax shortly after the young are born, is 
commonly on the wane when the nestlings have reached the age of 
two or three days, and seems to shade off into what I shall call 
' ^ intermittent brooding. ' ' In the cuckoo from shortly after hatch- 
ing to the age of one week, the young are brooded intermittently, 
subject in all probability to changes of temperature and light- 
intensity. When excessively hot or humid, this seems to shift 
into the shielding or spreading reflex. Thus a bird which begins 
to brood in great heat, will often gradually spread her wings, and 
assume the typical attitude, sometimes standing erect instead of 
sitting on the nest. Without any doubt the young are brooded 
continuously at night, but how long this night-brooding lasts 
I was unable to determine. While intermittent brooding is 
evidently related to the more continuous brooding of an earlier 
period, there is this difference that fear is again in the ascendant. 
How far intelligence enters into the question of brooding, as it 
possibly does, I am unable to determine. 
