144 A SUMMER ON THE YENESEI 



This tendency to flock before the young were 

 fledged is easily explained. Sociability is one of the 

 principal laws of animal life. It is abnormal to find 

 a solitary species, and where such a one occurs it can 

 generally be explained, as in the case of some birds of 

 prey, by a peculiar mode of feeding. But more often 

 it is due to the change produced in the animal world 

 by the rapid increase of mankind. It is worthy of note 

 that there are species living quite an isolated life in 

 densely inhabited regions, while the same species or 

 their nearest cogeners are gregarious in uninhabited 

 countries.^ 



To some extent this is the case with the golden 

 plover. In our own country breeding-grounds are 

 becoming scarce. You must walk very many miles in 

 England to meet with a dozen pairs of nesting plover, 

 and thus the birds scattered over the moors have no 

 incentive to congregate until the autumn, when their 

 numbers are recruited by migrants from the north. 

 But on the tundra, where the birds are plentiful and 

 live under primitive conditions, their natural inclination 

 towards social life is very marked, and the same applies 

 to the curlew-sandpiper. 



I used to wonder what brought the birds down from 

 the grassy hillsides where they nested into the 

 sphagnum marshes, and I came to the conclusion that 

 it must be the need of the young broods for water. 

 There is no doubt that it was the marsh that attracted 

 them. In August a number even came down to the 

 banks of the Golchika River, a mile or more from the 



* Kropotkin, Mutual Aid among Animals, p. 20 



