224 
FRANCIS H. HERRICK 
during the forty-two minutes that operations at the nest lasted. 
At 3. 30 p. m. two hours and forty-five minutes later, when the 
place was next visited, the female was brooding on the displaced 
nest, with her head turned in the same direction as previously 
noted. When frightened off this time, observe that in twenty 
minutes after the tent was entered, she captured and brought 
a large insect to the nest, held it four minutes in the mouth of one 
of the three nestlings present, until it was swallowed, inspected 
her brood and picked them all over, then settled over them and 
remained 22 minutes, until the call of the approaching male 
served as a signal for her relief. These details are given not only 
to show the rapidity of habit-formation, but to prove how quickly 
the behavior of a timid animal may become free in the face of 
abrupt changes in its environment. 
This nest still contained a single egg (fig. 15), which afterwards 
proved to be addle and was thrown out by the bird four days 
later. In entering the nest to brood, the cuckoo would clasp this 
egg with one foot, and after standing on it thus held for a few 
minutes, she would gradually settle down and draw it under 
her. In this way the egg was sometimes moved from the front 
to the far side of the nest. Gradually it came to be neglected, and 
can be seen to one side of the sitter in plate 6. 
At times the length of each brooding period would depend on 
the activity of the male, for he had a habit of coming to within 
a few feet of the nest, calling out the female, who would regularly 
take the insect from his bill, return and serve it. She would then 
either remain to brood, or quickly depart and reappear with an 
insect of her own capture. The young often rise up in the same 
eager excitement when the parent departs, as when she comes to 
them bearing food, which may be cited as one of many indica- 
tions of that lack of discrimination which they commonly show. 
At nest no. 3 also, I had the opportunity to watch the behavior 
of these birds during two severe rain storms, the first and heav- 
iest of which was on July 23 (table 5). In the first instance the 
rain began to come in torrents at 3.30 p. m., and almost at the 
same moment the female cuckoo was at the nest, fed her young, 
attended to their sanitary needs, and began to brood. As the 
water reached her, every feather at times became erect, when she 
