THE PIED WAGTAIL. 165 



by their feet to the clap nets, and make them struggle 

 violently and ntter cries of pain when a flight of the 

 same kind of birds is seen approaching ; these stop their 

 flight, and alighting are caught in large numbers for the 

 spit, their flesh, it is said, being very delicate. They share 

 too with Swallows the praise of being among the first to 

 announce to other birds the approach of a Hawk, and 

 join vv'ith them in mobbing and driving it away. 



About the middle of April, the Pied Wagtail begins to 

 build its nest. This is usually placed in a hole in a bank 

 or hedge, among stones, or in the hollow of a tree ; it is 

 composed of dry grass and withered leaves, mixed with 

 moss, and lined with wool, hair, and a few feathers. It 

 is a compact and solid structure, capable of protecting 

 the eggs and young from the damp soil, but is not gene- 

 rally concealed with much art; and hence perhaps it is 

 frequently selected by the Cuckoo, to lay an egg in. 



Towards autumn, Pied Wagtails for the most part mi- 

 grate southwards. In the midland counties they may be 

 often observed in large companies, in October, halting for 

 a few days wherever food is abundant, and then suddenly 

 disappearing ; after which only a few stragglers are seen 

 until the spring.' They return northwards about the 

 beginning of March. In the extreme south of England, 

 they are numerous all the year round ; but as many 

 instances have occurred of their alighting on a ship at 

 sea, it is probable that the majority migrate to some 

 southern climate, where the ponds do not freeze and gnats 

 gambol at Christmas. 



