BREEDING HABITS OF WEAVERBIRDS—FRIEDMANN 305 
To this I may add that regardless of how the first start is made, it is 
true that all through the nonbreeding season, the entire flock does a 
large amount of roofing and general enlarging of the whole affair so 
that it is true that subsequent individual nests are built into the large 
structure. The nests are added to year after year, and frequently 
become so large and heavy that they break the branches upon which 
they rest, and crash to the ground. All the birds seem to work 
together equally, apparently the males as well as the female(?)s, and 
even during the breeding season, when they have eggs or young in 
the nest, the male birds may be seen carrying straw to the roof or 
other parts of the common structure, not necessarily close to their 
own respective individual nests. The huge, massive affairs are 
composed wholly of dried grasses of a rather coarse, tough sort that 
grows commonly in southwestern Africa, and the seeds of which 
enter into the diet of the weavers very largely. The material is not 
really woven or even plaited on the surface of the nest, but is rather 
roughly put together in about the same way that hay is put into a well- 
made hay rack, but with a fairly definite thatching arrangement, 
causing the rain to run off and not soak through. The under side 
of the nest presents the rough, hard ends of the coarse straws and forms 
a very uneven surface. 
In the sparrow weavers and social weavers (subfamily Plocepas- 
serinae) we find, then, as far as our incomplete data permit us to 
generalize, an annual behavior cycle characterized by lack of migration 
or winter flock fragmentation, a substitution of a communal flock 
territory for individual ones as far as nesting is concerned, and a very 
marked development, both in seasonal duration and in individual 
activity, of the nest-building habit. The published observational 
data indicate that both sexes participate in nest building, but these 
data are open to question because of the similarity in plumage of the 
males and females; whether one or the other does most of the con- 
struction is not known. Nothing appears to be on record concerning 
the courtship habits, so it is not possible to ascertain whether this 
part of the cycle comes before or is associated with already completed 
nests as it is in some of the typical weavers (Ploceinae). 
Turning now to the next group, the weaver finches (subfamily 
Passerinae), which group includes the ubiquitous house sparrow 
(Passer domesticus) and its relatives, we find a different range of nest 
types. Some, like the house sparrow, build fairly bulky, formless, 
untidy nests in trees, on ledges, cornices of buildings, even in holes 
in trees, and other elevated sites (never on the ground). When 
built in the branches of a tree the nest usually is domed with an en- 
trance on one side, and fairly abundantly lined with feathers and other 
soft materials; when built in a hole the lining is much reduced as is 
