The Audubon Societies 



123 



destruction was formerly enormous, 'bird-ladders' have been constructed, forming a 

 sort of lattice below the light where the birds can rest instead of fluttering out their 

 lives against the glass. Again, in crossing large bodies of water, birds are often over- 

 taken by storms, and as their plumage becomes water-soaked, they are beaten down to 

 the waves and drowned. Sometimes thousands of birds are killed by a single storm. 

 But, of course, the vast majority of birds sweep on and arrive at their destinations in 

 safety. 



And so, if one steps out on a cloudy night, when the birds are migrating low to escape 

 flying through the moisture-laden clouds, he will hear their strange calls, only faintly 

 resembling their familiar daytime notes. Then he can picture to himself the thousands 

 of winged travelers returning from a sojourn in the tropics and pushing on through the 

 black night, guided by an innate sense of direction straight to their old homes. Then he 

 can think over the past ages through which this migrating habit has evolved to the days 

 when all North America basked in a tropical sun and birds darted among the palms and 

 tree ferns without ever a thought of 

 leaving the homes of their forefathers. 

 Then one can picture to oneself the 

 coming of the ice age and the destruction 

 of all the life that could not adapt itself 

 to the changed conditions or flee before 

 them. One sees the birds pushed gradu- 

 ally to the south, encroaching upon those 

 already there. One understands the 

 crowding that must have ensued, and 

 how these birds spread northward again 

 as the glaciers receded, only to be pushed 

 back once more by the coming of winter. 

 One contemplates how, with the with- 

 drawal of the ice and the evolution of the 

 seasons, these migrations, by repetition 

 through the ages, became permanent 

 habits or instincts; and, with the ensuing 

 modifications in the contour of the con- 

 tinent, and the changes in the location 

 of the food-supply, many variations 

 developed in the migration route of each 

 species which seem inexplicable today. 



One pictures these things to himself; one understands a little better the great mystery 

 of the bird's life; and, perhaps, one appreciates somewhat more fully the presence in our 

 thickets and gardens of these songsters, whose lives are ever one series of hardships and 

 dangers, and yet which, withal, are so expressive of the happiness and joy to be derived 

 from nature. 



QUESTIONS 



1. Name five birds that are permanent residents in your locality. ' 



2. Name ten birds that are summer residents. . , • 



3. Name ten birds that are transient visitants. . • •. 



4. Name five birds that are winter visitants. 



5. What is the earliest date of arrival of the Robin in your locality? The Bluebird? 

 The Phoebe? The Red-winged Blackbird? The Canada Goose? The Bobolink? The 

 Baltimore Oriole? The Scarlet Tanager? 



6. Why do some birds return earlier than others in the spring? 



A BANDED HOUSE WREN 

 By marking birds with aluminum bands it has 

 been proven not only that many come back to the 

 same place each year, but also that they winter in 

 the same locality year after year. 



