THE PAEADISE OF THE OHAEADEIID^, 



53 



circumference. This belt is crowded with migratory birds eager to push forward to their 

 breeding-grounds — hurrying on over the melting snow so long as the south wind makes the 

 bare places soft enough to feed on, but perpetually being driven back by the north wind, 

 which locks up their food in its ice-chest. The great majority of migratory birds follow 

 the river-courses — partly because they are landmarks which guide them on their long and 

 venturesome journeys, and partly because the rapid rising of the rivers and the steepness of 

 their banks causes open water and bare ground to be a hundred miles ahead of similar 

 feeding-places elsewhere. 



It is impossible to overestimate the important role which the wind plays in the melting 

 of the snow on the tundras, the breaking up of the ice on the rivers, and consequently in 

 controlling the migration of birds. In watching the sudden arrival of summer on the 

 Arctic Circle, both in the valley of the Petchora in East Russia, and in the valley of the 



Yenesay in Central Siberia, 

 I was impressed with the 

 fact that the influence of the 

 sun was nearly nothing, 

 whilst that of the south 

 wind was almost everything. 

 The great annual battle 

 between summer and winter 

 in these regions is the one 

 event of the year, like the 

 rising of the Nile in Egypt ; 

 it only lasts a fortnight, 

 during which a cold winter 

 is transformed into a hot summer. Ten years ago, 

 when I was waiting for the arrival of summer on a 

 ^^iW" \^'f 'f'/*?^''^ ! tributary of the Yenesay in lat. 66J°, a few hundred 



miles south of the limit of forest-growth, the only sign of approaching summer, before the 

 end of the first week of May, was the arrival of a few species of migratory birds, of which 

 Snow-Buntings and Eedpoles were the commonest. On the 5th of May a solitary Swan 

 was seen, and on the 9th we had the first attempt at rain for more than six months, which 

 brought a solitary Goose in its train ; the following day half a dozen Geese were seen, 

 and on the 16th we actually saw a Barn-Swallow. But we soon discovered that one 

 Swallow does not make a summer, though several flocks of Geese seemed to think it did. 

 The last half of May was stormy ; there were signs of rapid thawing further south as the 

 level of the river rose considerably ; many flocks of Geese and Swans passed us ; but even 

 as late as the 30th of May it was midwinter, both where we were and further north, for all 

 the flocks of Geese were flying south, having evidently been unable to find any open water. 

 On the 1st of June the crash came. Summer, in league with the sun, had been fighting 



Crowds of 

 migratory 

 birds. 



Comparative 

 influence of 

 sun and 

 wind. 



Earliest 

 arrivals of 

 migratory 

 birds. 



