138 ENGLISH BIRD LIFE 



arose from the marsh, which were covered with a 

 tangled growth of willows and birch, none of which 

 were more than eight or ten feet high. On one of 

 these islands, the Fieldfares had formed a small 

 colony, notwithstanding the stunted character of 

 the trees. The deserted nests were in evidence, and 

 a few birds still hung about the boughs. 



The wandering habits of birds of this type form 

 something of a stumbling-block to the philosophers 

 who seek to reduce avian migration to some fixed 

 law. The Fieldfare is a typical Norwegian bird. 

 Around the cultivated patches about the home- 

 steads ; on the narrow level stretches which lie 

 between the lake-margins and the feet of the steeply- 

 ascending hills; in the mountain ashes which grow 

 on the roadside; these Thrushes congregate in the 

 autumn, preparing to cross the North Sea. Their 

 reason for this movement appears plain. In a little 

 while the snow which even in mid-July covers the 

 higher crests, and lies deeply in the hill-hollows, 

 will have invaded the valleys, and the food-bearing 

 areas will be buried far beyond the reach of hungry 

 bills. But why, having braved the perilous flight, 

 and when the temperate shores of England are 

 gained, should the Fieldfares crave again the sterner 

 surroundings of their birthplace ? In the springtime 

 when they gather together to return, the conditions 

 of life in England are growing more favourable day 

 by day. The food which suffices for their con- 

 geners of precisely similar tastes is becoming more 

 and more abundant. Here at hand are secluded 

 retreats, woods and coppices, in which they may 

 nest in security ; and here the summer climate differs 



