216 The Chimney Swift 
they are always associated in scattered companies, but 
for a few weeks before the fall migration they are 
decidedly gregarious, roosting in great numbers ir 
favorable localities. 
One species of the swift family, which breeds in 
various parts of the Malay Archipelago, is famous for 
making an edible nest. It was thought for a long time 
that the substance, used by the birds in the manufacture 
of these nests, was chiefly seaweed, partly digested and 
mixed with mucus from the salivary glands, but from 
recent chemical analysis it has been proved beyond 
doubt that it is mucus alone. There are some famous 
swift caves in the northern part of Borneo, and I quote 
the following from Mr. H. Pryer, who visited these 
caves some time ago: 
“At the White Cave and others I saw the nest- 
gatherers at work getting in their crop. A thin rattan 
ladder was fixed to the end of a long pole and wedged 
against the rocks. ‘Two men were on the ladder; one 
carried a long four-pronged spear, a lighted candle 
being fixed to it a few inches below the prongs. By the 
aid of this light a suitable nest is found, and transfixed 
with the prongs; a slight twist detaches the nest un- 
broken from the wall of the rock. The spear is then 
passed within reach of the second man, who takes the 
nest off the prongs and places it in a pouch carried at 
