BARRO COLORADO ISLAND—GROSS 335 
peccaries, monkeys, the ocelot, and the jaguar, are much more afraid 
of you than you are of them. 
The first bird which received special attention after landing at 
the station was the oropendola (Zarhynchus w. wagerli), a large, 
beautiful bird marked with rich brown, black, and yellow, commonly 
known as the hangbird or hangnest. This bird, which nests in large 
communities, attaches its long, pendent nest to the topmost branches 
of the tallest trees, that often tower high above the other trees of 
the jungle. A tree of this kind which contained about 50 nests 
formerly stood in the back yard of the laboratory, but, unfortu- 
nately, it was blown down by a storm. An examination of the nests 
revealed that only two of them were occupied. These contained half- 
grown young that were killed when the tree crashed to the ground. 
We preserved the young and all of the nests, which gave us a fine 
series for measurements and study. The birds remained in the 
vicinity several days after this catastrophe, apparently very much 
attached to the old nesting tree. The large number of birds that 
were there before and after the tree fell lead us to infer that the 
nests may be used for roosting places long after the young birds are 
able to fly. ‘The presence of oropendolas about the laboratory was 
always made known by their characteristic calls, which are so dif- 
ferent from those of other birds. The notes have a peculiar gurgling 
liquid quality, which has been described as “ wo-kee’, oak-la-hom’ e,” 
reminding one somewhat of the notes of their relatives, the bobolinks 
and the redwings, all members of the family Icteridae. At other 
times there were notes which sounded much like those produced when 
large pebbles are thrown into the water. Later in the summer we 
found another oropendola tree, which stood near the head of an 
adjoining cove, but the height of the tree and the inaccessibility of 
the nests made it very impracticable for life-history study. 
On June 28 one of the Indian boys at the laboratory found a 
pendent nest of a small flycatcher attached to a long, flexible stem 
overhanging the water of the lake in a place not far from the boat 
landing. When it was pointed out to us it did not seem like a nest 
but appeared more like a bit of grass and débris which had acci- 
dentally become lodged in that position. The entrance to the nest 
was unusual in that it was completely hidden from view by a cov- 
ered pasageway, which further aided in its concealment. The 
entire structure and location of the nest seemed to us ideal, as far 
as protection from enemies was concerned. It was out of the reach 
of peccaries, coatis, and members of the cat family, and even the 
prowling, mischievous monkeys would not dare to descend such a 
slender branch so near the water. Before the summer had progressed 
very far we found many of these nests, some in similar locations 
along the margin of the lake but more of them overhanging the water 
