THE LONELIER HOURS 



165 



In proportion to its gentle pitch the distance to which 

 the sound will travel is remarkable, but much energy must 

 go to its utterance. Close observation in the early twilight 

 has shown the lower mandible of the bill intensely quivering 

 while the sound was being produced, and there is the same 

 hint of force in Gilbert White's record of how the Selborne 

 summer-house quivered when a nightjar perched and mur- 

 mured on the roof. It seems clear that the song, like the 

 sedge-warbler's, is prolonged after the breeding season, 



NIGHTJAR 



though nightjars are late nesters. Depending like swifts and 

 flycatchers on a diet of summer insects, they do not arrive 

 till May, and their eggs are often to be found in the middle 

 of June. In the earlier weeks of their stay, when the cocks 

 are probably seeking their mates, a reduced half-whispered 

 jarring is sometimes to be heard uttered from the ground on 

 ferny commons and in the woods. The same tentative 

 murmur is sometimes heard early on a June morning a little 

 before sunrise, but the shades of evening and the early night 

 form the song-time for this nocturnal bird. 



It is rarer to see the nightjar hunting than churring, 

 because of the increasing darkness ; but it will sometimes 

 reap a harvest of the little moths that buzz on warm even- 



