82 THE BIRDS OF SOMERSET HILLS 



the Cliff, with straws added, but is of 

 a different shape. The nest of the Cliff 

 Swallow is globular and hangs down- 

 ward. The Barn Swallow's nest is 

 usually placed on a rafter or in the cor- 

 ner of a barn and is cup-shaped. It is 

 a common sight to see several of these 

 Swallows sailing low over the fields or 

 meadows, catching insects. Their twit- 

 tering note can be distinguished from 

 that of the other Swallows. Both males 

 and females incubate, the female the 

 greater part of the time. The period 

 of incubation is about thirteen days. 

 Once when I watched these birds as they 

 were nesting, each bird would remain 

 on the nest for about eight minutes. 



