358 THE LIVING WORLD. 
trolled by a master spirit, who seems to determine the tree upon which the 
nests of his subjects shall be erected. When this is decided the birds- first pro¬ 
ceed industriously to make a thatch roof, which they perform by carrying dry 
grasses, selected from a wiry species known as boosckmanees grass, which is 
hung over the branches and ingeniously interwoven until a dome-shaped roof 
is made, so compact as to turn rain. 
On the under sides of this thatch they fasten a number of separate nests, each 
being inhabited by a single pair of birds, and only divided by its walls from the 
neighboring habitation. All these nests are placed with their mouths down¬ 
ward, so that when the entire edifice is completed, it reminds the observer very 
strongly of a common wasp’s nest. This curious resemblance is often further 
strengthened by the manner in which these birds will build one row of nests 
immediately above or below another, so that the nest groups are arranged in 
layers precisely similar to those of the wasp or hornet. The number of habita¬ 
tions thus placed under a single roof is often very great. Le Vaillant mentions 
that in one nest which he examined there were 
three hundred and twenty inhabited cells, each of 
which was in the possession of a distinct pair of 
birds, and would at the close of the breeding sea¬ 
son have quadrupled their numbers. 
The sociable weaver bird will not use the same 
nest in the following season, but builds a new 
house, which it fastens to the under side of its 
previous domicile. As, moreover, the numbers of 
the nests are always greatly increased year by 
year, the weaver birds are forced to enlarge their 
thatched covering to a proportionate extent, and in 
course of years they heap up so enormous a quantity 
of grass upon the branches that the tree fairly 
gives way with the weight, and they are forced- 
to build another habitation. So large is this thatch¬ 
like covering, that Harris was once deluded by the 
distant view of one of these large nests with the 
belief that he was approaching a thatched house, 
and was only undeceived, to his very great dis¬ 
appointment, on a closer approach. 
The object of this remarkable social quality in the bird is very obscure. As 
in many instances the nests of the weaver birds are evidently constructed for the 
purpose of guarding them from the attacks of snakes and monkeys, the two 
most terrible foes against which they have to contend, it is not improbable that 
the sociable weaver birds may find in mutual association a safeguard against their 
adversaries, who might not choose to face the united attacks of so many bold 
though diminutive antagonists. The shape and general aspect of the nests varies 
greatly with their age, those of recent construction being comparatively narrow 
in diameter, while the older nests are often spread in umbrella fashion over the 
branches, enveloping them in their substance, and are sometimes only to be 
recognized as a heap of ruins from which the inhabitants have long fled. 
In general the social weaver bird prefers to build its nest on the branches 
of some strong and lofty tree, like the giraffe thorn previously mentioned, which 
ORCHARD ORIOLE. 
