CHAPTER VII 



ROUND THE YEAR IN THE BRITISH ISLES : WINTER 



The migrations observed in the British Isles during the 

 winter consist of: (i) movements between various 

 parts of our area ; (2) emigrations from our shores ; 

 and (3) some immigration from the Continent. All 

 these are due to the effect of meteorological conditions 

 of an adverse nature upon the food supplies, either 

 within the British area, or on the Continent. 



Not very long after the last of the summer guests 

 have bidden us a2i revoir until another spring, and while 

 the autumn visitors have scarcely ceased to arrive to 

 spend the winter, another set of bird-movements may, 

 sooner or later, be ushered in — forced migrations to 

 escape the rigors imposed by the season. 



The date on which such disturbances and their 

 consequent evictions take place, depends upon the 

 climatic aspect of the season. They may commence in 

 November, and are not unknown to March ; but 

 December and January are the main months for their 

 occurrence. 



Few winters are entirely free from cold spells, and 

 some are notable for their severity. When the land 

 becomes icebound, or a pall of snow covers its surface, it 

 is impossible for many birds to obtain food, especially 



