26 THE BIRDS OF BERKS AND BUCKS. 



juvenile bird's-nester. Ten or a dozen eggs appear to 

 be the usual complement, but I have known as many 

 as fifteen to be laid. 



Family MOTACILLID^E. 



PIED WAGTAIL (Motacilla Yarrellii). Local name, 

 DisJnvasher. Very common, remaining with us all the 

 year. Small flocks congregate in cold weather, but 

 many individuals disappear in winter, when I have no 

 doubt they move to a warmer climate, as they do not re- 

 appear until spring returns. They are, nevertheless, 

 hardy and pugnacious birds ; I have seen them fighting 

 when snow covered the ground. The partiality which 

 this bird seems to evince for building in fagot stacks is 

 remarkable, and in May 1860, a nest was taken under 

 the roof of the Formosa boat-house, at Cookham. 



GREY WAGTAIL (Motacilla boaruld). A winter 

 visitor to most of the southern counties of England, 

 and a summer one to the more northern. I have 

 seen specimens killed near Windsor, Eton, Surley, 

 Datchet, and other places. It is often observed on the 

 banks of the Thames in winter, but a few have been 

 procured in summer. They are rarely seen in larger 

 numbers than pairs. I was rather surprised to be 

 informed by the Rev. Bryant Burgess, of Latimer, 

 Chesham, that this wagtail annually makes its nest 

 and rears its young on the banks of the little Buck- 

 inghamshire river the Chess, where it seems to be 



