304 Bird - Lore 



make this matter a little clearer. In our study, so far, we have traveled north 

 and south with the birds to learn the routes which they follow to their 

 summer and winter homes. Let us now take the map of the western hemis- 

 phere and look at it from east to west, or west to east. See what a remarkable 

 outline North America has, compared with that of the Eurasian continent of 

 the eastern hemisphere! In the first place, its greatest breadth is in the far 

 north, where the land is covered with snow and ice most of the year, while 

 down near the line of the tropics, where the temperature never reaches the 

 freezing-point, there is very little land. In fact, North America is nearly all 

 water instead of land imtil one reaches the United States, for the Gulf of 

 Mexico and Caribbean Sea, to say nothing of the great oceans, cut so deeply 

 into its surface. 



Notice, in the next place, that most of the lofty mountain ranges and 

 practically all of the dry, treeless places are in the western part of this great 

 continent, whereas the east has most of the large inland bodies of water. You 

 can easily find on the map and name these mountain-ranges, plains and 

 plateaus, and gulfs, lakes and bays. It will be well to spend a few moments 

 in looking up the courses of the great rivers, too, because they play an impor- 

 tant part in the birds' map of America. It is a curious fact that many birds 

 never go far west of the Mississippi River, while many others do not come so 

 far east as its borders. Moreover, some of those which frequent the eastern 

 United States stop in their northward journey not far above the Ohio River; 

 others follow up the Hudson and Connecticut River valleys a considerable 

 distance, leaving most of their kind further south; while a variety of birds 

 find a congenial summer home all the way north from Nova Scotia, New 

 Brunswick, Canada, Ontario and Lake Superior northwestward to Alaska. 

 Just why there is such diversity in the distribution of our summer neighbors 

 and spring travelers, it is hard to say, but climate, food-supply and favored 

 nesting-haunts may account for it in part. 



Far north, it makes little difference whether one is in Greenland, the 

 Hudson Bay region or northern Alaska, there is almost no vegetation, and 

 always snow, ice and a cold, chilling temperature. On the birds' map this 

 inhospitable expanse is called the Arctic Zone. By circling the North Pole, 

 one would find no change in these conditions, and consequently little differ- 

 ence in the vegetation and animals which seek a home there. The bleakest 

 part of this zone, which is in Greenland, about Hudson, Bay and along the 

 eastern edge of Labrador and Newfoundland, is known as the Barren Ground 

 fauna; that in northern Alaska, as the Alaskan- Alpine fauna. 



Perhaps you should know what is meant by the word fauna, because it is 

 a word used so frequently in the geography of animals, just as the word flora 

 is, in the geography of plants. Fauna means the whole number of animals 

 found in an area where the climate and conditions in general are much the 

 same. Flora means all the kinds of vegetation in a like area. The ancients 



