ENVIRONMENT, PAST AND PRESENT 77 



that reared them. They go neither with their true 

 parents, which depart long before they are ready to 

 travel, nor with their foster-parents. They find 

 their own road when the time comes. It is their 

 very first taste of migration but they nevertheless 

 take the correct road. The numerous waders that 

 breed on the barren lands to the north of us, prac- 

 tically all leave their young as soon as they can feed 

 themselves, and depart south. Later, but inde- 

 pendently, the young follow. When they reach us 

 in September far behind their parents, they are 

 hopelessly mixed up and seven or eight species are 

 frequently seen together in a flock, all birds of the 

 year. But winter finds them in their correct 

 quarters, be it the Argentine or Florida, Peru or 

 California. Our Franklin gulls, which breed locally 

 in colonies of many thousands, pay no attention to 

 their young after these can feed themselves. They 

 are left to find their own way to Texas and Peru. 

 The extreme case is undoubtedly the American 

 golden plover. The adults take the Atlantic route 

 south while the young travel by themselves, 2000 

 miles to the west, through the interior of Canada. 

 Yet they re-join their parents later in the Argentine. 

 It is their first migration. Intent must be entirely 

 ruled out. They cannot even be conscious of the 

 fact that they are travelling south or making for 

 the Argentine. 



