434 ZOOLOGY 



forest, from tree to tree, or along the fence rows, living on the 

 country. Sometimes it is just a slow retreat before the advanc- 

 ing cold or progress with the advancing spring. At other times 

 it may involve long flights. 



The golden plover illustrates an extreme case. They breed 

 in the arctic circle in June and July. They "winter" south of 

 the equator in South America from September to March; that 

 is to say during the southern summer. Their course in the north- 

 ward spring migration is not fully known, but it is believed that 

 they follow an overland route over northern South America, 

 Central America, Mexico, Central United States and Canada 

 to their Arctic breeding grounds. The return journey south- 

 ward is better known. From their breeding grounds they go to 

 Labrador in August. Here they feed on berries and grow fat 

 after their relative fast. They work their way down to the coast 

 of Nova Scotia. Here they desert the land and fly across the 

 ocean to the eastern shoulder of South America. They may stop 

 temporarily in the islands of the West Indies ; or they may make 

 the whole distance apparently without stop. In the course of a 

 few weeks they cross the equator and reach their southern- 

 most terminus in Argentina. Some other species have been 

 followed with equal care and have almost equal range. 



Birds have many enemies among animals. Some of the birds 

 are prey to other birds. Snakes, some lizards, and many of the 

 smaller mammals feed upon them whenever they can. Many 

 eggs are eaten by these and other animals. During the nestling 

 stage birds are in especial danger. The parents themselves are 

 often taken at this time. Man himself has probably proved the 

 worst enemy of the birds, which is scarcely wise or fair, since the 

 birds are among his best friends. 



443 . Relations of Birds to Man. — Man has directly destroyed 

 many of the wild birds for food, for their plumage, for sport, or 

 because he deemed them injurious to his interests. In an in- 

 direct way he has destroyed even more. Many of the birds do 

 not take kindly to civilization, but prefer the quiet of unchanged 

 nature for feeding and breeding. Such birds have been gradu- 

 ally pushed into more limited or less favorable territories. 



