122 Bird - Lore 



and pushes his way steadily up to the treeless and grassless, snow-covered 

 peak where the air is cold and thin. 



Learning the heights of mountain-peaks or the different depths of the salt 

 ocean and fresh- water lakes and bays will mean much more to us, if we stop 

 to think of the many kinds of plants and animals which make their homes all 

 over the earth, at different heights and depths of the land and water, and in 

 different cHmates. 



Looking down now upon the earth, as the flying bird does, we see great 

 plains and mountains; vast forests and long stretches of desert where neither 

 trees nor grass grow; lakes, large and small; rivers with fertile valleys, and 

 crooked coast-lines, here rocky and boldly jutting out into the ocean, while 

 yonder, gently sloping down to the water's edge in shining, sandy beaches. 



Should we try to look down through the ocean or great inland bodies of 

 water, we should find a water-world more strange and quite as wonderful as 

 this land-world, one where many curious animals and plants live at different 

 depths. Among these water-folk are some great travelers. While seeds are 

 sprouting and leaves are unfolding, while bears and other hibernating animals 

 are waking up from their long sleep, and migrating birds are starting on their 

 long journeys, the leaping salmon leave the sea and, entering some river's 

 mouth in schools, swim steadily against the current toward its head. Around 

 eddies and rapids these fishes go, surmounting falls and artificial dams by 

 great leaps, until at last, thin and exhausted, they reach the spot which instinct 

 has taught them to seek, where they may safely deposit their eggs. 



No one has yet succeeded in fully explaining why each springtime sees so 

 many finny, furred, and feathered travelers on their perilous paths. 



Different kinds of land and water, different degrees of heat and cold, differ- 

 ent heights and depths, along with many other things doubtless, play a part 

 in this mystery. 



Looking over our map again, it might help us to trace some of the trails 

 over which migrating birds travel, for, by following these airy highways, we 

 shall be getting a bird's-eye viev: of all North America. 



Starting from the tropics, in the latitude of the Isthmus of Panama, let 

 us see how many ways there are of getting from South America to North 

 America. 



There is certainly very little land and a great deal of water to choose 

 between, but since birds fly whither they please, the one really important 

 matter to take into account is food. 



You and I would need much extra clothing for a journey from the tropics 

 to the Arctic Circle, but the birds' chief concern is for food. The suits of 

 feathers which they wear protect them from the cold as well as from the heat. 

 A very high wind or a hea\'y storm might interfere with their movements, but 

 in any ordinary weather, the birds have no concern for the protection of their 

 bodies. 



