28 ANIMAL LIFE 



The full epiphany of animal movement is seen 

 in the behaviour of migratory flocks. Migration is 

 essentially an oscillation between breeding-ground and 

 feeding-ground. On the first, nests are made and the 

 young reared and educated ; on the second, parents and 

 young have no connection. Each lives to himself 

 and the young grow to maturity. 



When the nesting season approaches, an impulse, 

 the most powerful and selective in animal life, draws 

 mate to mate and fills unmated migrants with a longing 

 that cannot be satisfied save in a far river, or sea, or 

 country. Mated couples of birds desire the particular 

 cottage eaves or hollow on a moorland that has served 

 them for nesting so long ; the pride of the hook-jawed 

 salmon is only satisfied by the river that he left last 

 year for the sea ; while the upstream eels that leap 

 with the first autumn spate, congregate in a thick 

 mass on their start for the sea. 



In this rush for the breeding-ground a new appear- 

 ance envisages the migrants, a new strength possesses 

 them; instincts that lay dormant rise up and direct 

 their way, notes unknown save at this time of dangerous 

 travel are heard. 



Then all our migrant birds make for the north. 

 The ducks, geese and waders, the fieldfares and 

 redwings, leave us for the Arctic, for Norway and 

 Siberia. From the south come our swallows, warblers, 

 cuckoos. Wave after wave, starting from Algiers, Tunis, 

 Syria, and even the coasts of the far south, send north- 

 ward their migrants seeking homes. Rarely do they 



