10 
of what they eat, namely, flying insects. The first two 
destroy vast numbers of gnats, mosquitoes, and other small 
flying insects. During the day they are constantly on the 
wing. The swallows (laiang laiang ) occasionally rest dur¬ 
ing the day, but the swifts (buta buta, saiao) probably 
remain in flight until they go to roost in a cave or a hollow 
tree. As the light of day fades and the largest stars can 
first be distinguished, a bird several times larger than a 
Fig. 8. Luzon calao, Hydrocorax hydro- 
oorax (Linnseus). (From a speci¬ 
men mounted in the Bureau of 
Science.) 
swallow sails over the land. This is a nightjar. This bird 
is often called a nighthawk, and it might with equal pro¬ 
priety be called a nightswift or a nightswallow. In many 
countries it is called goatsucker (Spanish, chotacabras ) 
from an old belief that it sucked milk from goats. In 
some parts of the Philippines it is called tucaro in imitation 
of its call. The nightjars begin the work of insect destruc¬ 
tion at the time when the swallows and swifts have gone to 
rest. 
Fig. 9. A large Philippine woodpecker, 
Thriponax pectoralis Tweeddale. 
(From Cat. Birds Brit. Mus., vol. 18.) 
