WILD LIFE OF ORCHARD AND FIELD 



making, when the sky is blue and the sun bright, 

 a warm and deHcious picture such as the Greeks 

 must have loved to gaze on. 



"As each bird, however, only works at his own 

 and his partner's hole, it is evident that this kind 

 of social working is not the same as that of ants 

 or bees and other such insect communities, though 

 it has something of that appearance. Sometimes, 

 for a short time, all the birds will keep fluttering 

 round in small circles that only extend a little be- 

 yond the face of the cliff, not rising to a greater 

 height than their own tunnels in it, which they 

 almost touch each time as they come round. They 

 look like eddies in a stream beneath the bank, but 

 are not so silent, for all are twittering excitedly. 

 This is an interesting thing to see — a kind of aerial 

 manoeuvres, the special cause of which, if there be 

 one, is not obvious.'^ 



Sometimes the nest is carried to a far greater 

 depth than two or three feet, as in a case observed 

 by Mr. Fowler, in Beverly, Massachusetts, where, 

 in order to get free of a stony soil, where pebbles 

 might be dislodged and crush the eggs, the tunnel 

 was carried in nine feet, while neighboring birds 

 in better soil only went a third as far. In one place 

 the burrows will be close to the top of the bluff; in 



286 



