Extracts from Diary of Otto Widmann 57 



montlis. As the Swifts live entirely on small winged 

 insects and have to catch them on the wing, weather con- 

 ditions influence all their functions, not only the building 

 of their nests, but even the deposition of their eggs, of 

 which 4 to 6 are laid. Like most eggs deposited in dark 

 places their color is white, but while a Canary hatches its 

 eggs in 13 days, it takes the Swift 17 to 19 days. Both 

 parents not only help in nest building, but also in incu- 

 bating and feeding the young. The incubating parent 

 spreads its breast protectingly over the base of the nest 

 and, when necessary, spreads its wings over its contents. 

 The young ones, too, lie with heads to the base and the 

 anal region protruding over the rim to keep the nest 

 clean. Several nests may be found in one chimney, but 

 never one below the other. The young make a strong 

 hissing noise when the feeding parent appears, and when 

 three weeks old fly with the same hiss against the face of 

 an intruder of their home. They are at least four weeks 

 old when able to try their wings for a first flight, but are 

 brought back to and fed in the chimney for some time 

 afterward. AVhen nest building is completed, the salivary 

 glands beneath the tongue shrink and when feeding young 

 this space is used as a pouch to store the insects for the 

 young. In feeding the parent thrusts its head deep into 

 the wide open mouth of the young, ejecting the contents 

 of its pouches with jerky motions. That these consist 

 partly of living insects is seen when the parent's head is 

 retracted and minute insects appear trying to escape 

 from its bill. This explains the peculiar cleaning of the 

 bill after feeding. That the Swift, like most other birds, 

 returns to its former home to breed has again been dem- 

 onstrated by Mr. BajTies who banded one in 1911 and 

 caught the banded bird the following year when it came 

 again down into the same room. 



Swifts are very devoted to their young and instances 

 are known when they have risked and sacrificed their 

 lives in the attempt to reach them in burning buildings. 



