304. ANNUAL REPORT SMITHSONIAN INSTITUTION, 1949 
was about 5 feet high. The part that had broken off must have been 
about 5 feet in diameter each way. This nest contained about 95 
nests within it. 
In a locality where these birds occur it is impossible to remain long 
unaware of their presence. ‘Trees are not so numerous but that each 
one becomes an object of more or less importance in the landscape. 
Needless to say a tree on which there is a social weaver’s nest is a very 
conspicuous object, visible for a great distance and widely proclaims 
the presence of the builders. But the birds themselves soon intrude 
upon one’s consciousness with their noisy, harsh, chattering notes as 
they fly by in flocks or feed in scattered bunches upon the seeds of the 
small, stunted shrubs and plants that wrest an existence from the 
inhospitable soil. While feeding they keep up an incessant chatter 
much like a flock of house sparrows, and, like them, frequently quarrel 
over bits of food. In flight they all act in unison with a precision 
quite remarkable for birds of their type, the whole flock turning, 
rising, falling, wheeling, and stopping more or less together. 
Although the birds live in compound “‘apartment-house’’ nests, 
feed and fly in flocks, and are at all times exceedingly gregarious, they 
seem to establish fairly strong mating relations as far as my field 
observations indicate. If they were haphazardly promiscuous they 
would be forever in each other’s way getting in and out of the entrance 
holes of the individual nests in the large communal structures. As a 
matter of fact, the harmony of life within each colony, the lack of 
what may be likened to traffic congestion, i. e., the coming and going 
of birds in the task of providing food for the young, the fact that out of 
numbers of individual nests examined by various observers none were 
found with unusual numbers of eggs or young, all argue for individu- 
ality in nest occupancy. Whether each male has only one or several 
mates is, however, unknown. 
There have been several attempts to explain the structure of the 
large, composite nests of this species, some writers claiming that each 
pair of birds builds an individual nest, all of them close together, and 
then the flock builds the common roof over all the nests, while other 
writers have recorded that the flock builds a large structure and then 
each pair builds its individual nest into this structure. J never saw 
the actual beginning of a nest, and the smallest nests I found were, as 
mentioned above, complete structures with numbers of nests within 
them. However, Roberts (1940, p. 333) describes the construction 
of the communal nest as follows: 
. . . first a roof is constructed of coarse straws in the strong branches of a large... 
tree, and under this a great number of nest-chambers are made by nipping off 
the straws to form a tunnel upwards with a chamber at one side of the top of the 
tunnel; each pair of birds has its own nest-chamber, and scores of pairs may 
occupy the same colony. 
