BARRO COLORADO ISLAND—GROSS 339 
blind with the floor slightly above the level of the nest, where I 
could look down into it, a good position for observation and pho- 
tography. The sides of the blind were covered with branches and 
large banana leaves, and for the top I used a piece of metal 
roofing secured at the laboratory. A roof is very essential during 
the rainy season because a torrential downpour is a part of your 
daily expectation and though a wetting of yourself is of little con- 
sequence it is important to keep your camera equipment dry. The 
study of these antvireos was one of my most pleasant ornithological 
experiences at the station and I became very much attached to these 
birds before it was ended. 
There was always complete cooperation in this family in all of 
the arduous tasks concerned with incubation and care of the young. 
The male and female relieved each other at regular intervals of 
two or three hours throughout the day. The birds approached the 
nesting tree walking on the ground rather than flying from the 
branches above. Just before the shift took place I could hear the 
approaching bird singing a sweet warbling song. When it reached 
the base of the tree it hopped to the lowest branch and then came 
up limb by limb, singing as it came. As it peered over the margin 
of the nest it seemed to utter notes of greeting, and then without 
further ceremony the birds exchanged places. Both birds sang and 
approached the nest in a similar manner, but it was interesting to 
note a slight difference in their behavior regarding the position 
assumed on the nest. The male usually faced the blind, as shown 
in the accompanying photograph, while the female with greater 
modesty nestled with her head in the opposite direction. While this 
study was in progress a spotted antbird (Hylophylax naevioides) 
built a beautiful nest, which I could clearly see and observe from the 
back porch of my blind. My attention and my interests from that 
time on were divided, a condition which might be compared to a 
two-ring circus. The spotted antbird, like the ant vireo, sang when 
it approached the nest. Long before I saw the bird I could hear the 
loud, clear, robin-like calls coming nearer and nearer from out of 
the depths of the jungle. When the male was about 10 feet away 
the female would fly off. He seemed to pay no attention to his 
mate, but continued toward the nest in a leisurely fashion, singing 
as he came. Much to my surprise, he would continue to sing after 
he was on the nest for several minutes. As I sat watching this 
beautiful enactment of life I could not help thinking that the spirit 
with which these birds approached their tasks is an example for all 
of us to follow. 
