274 



AMERICAN FORESTRY 



But with the later migrants, such as the shorebirds, 

 that have a long way to go, the females usually arrive 

 with the males, and with some species, courting takes 

 place en route and they arrive at the breeding ground 

 fully mated and ready to nest. 



In the October number of American Forestry, in 

 considering the departure of the birds, mention was made 

 of the distance traveled by different birds in their migra- 

 tions and here again it is interesting to note where birds 

 have wintered as explanatory of the time of their arrivals 

 in the spring. The early migrants are those that have 

 spent the winter entirely within the United States. This 

 is true of all the INIarch birds in the northern states but 

 during the last of the month, the first birds from the 

 West Indies and Mexico begin to arrive in the southern 

 states. About the middle of the month many of the 

 birds that have wintered still further south begin to ar- 



A BUSY WORKER 



Tliis red-eyed vireo is busy repairing its nest. Tlie bird winters in 

 northern Soutli America and arrives in the northern States during 

 the first part of May. 



rive, including the swallows, the spotted sandpiper, the 

 black and white warbler and the water-thrush. The last 

 of April and first of May brings even to the northern 

 states the initial wave of birds from Central America 

 and perhaps even northern South America and about 

 the middle of this month, when occurs the height of the 

 migration thousands of tiny warblers, vireos and fly- 

 catchers that have been wintering on the slopes of the 

 Andes or the pampas of Brazil, arc winging their ways 

 ■overhead to Labrador, Hudson Bay and Alaska. The 

 shortest route which one of the very last to arrive, the 

 blackpoll warbler, may traverse, is 3,500 miles, while 

 those which nest in Alaska must travel over 5,000. 

 Some of the shorebirds which bring up the close of the 

 migration in late May or early June have undoubtedly 

 come from Chile and even Patagonia and still have sev- 

 eral thousand yet to go so that before they reach their 

 nesting grounds again, they will have traveled 16,000 

 miles since leaving in the fall. 



This constrains us to wonder how these tiny wayfarers 

 are able to traverse such tremendous distances and still 



return so accurately to their homes. That they do so is 

 certain, for many birds have been marked so that we 

 know that the same bird often comes back to the same 

 place year after year and builds a nest close to the one 

 of the previous year. 



At one time it was though that the^• had well-marked 



A KlAG M.L!.:,i.j li.! '\ 1.:: 



Tliis bird winters as far South as Patagonia and does not reach tlie 

 northern States until the last of May or the first of June. 



highways in the mountains, rivers and coast lines, sur- 

 \eyed, as it were, by their ancestors and unfailingly fol- 

 lowed by all descendants. But now it is believed that these 

 highways are followed only so far as they afford abun- 

 dant food and when the food supply lies in some other 

 direction, they are regardlessly abandoned. What is it 

 then that guides them mile after mile in their flights, 

 flights made mostly under cover of darkness and often at 

 altitudes varying from 3,000 to 5,000 feet above the 

 earth? A sense of direction, it is now called, an instinct 

 for recording directions as accurately as a compass which 

 we, having only so crudely developed in ourselves, are 

 at a loss to understand; an instinct which permits birds 

 to travel north, south, east or west and not loose their 

 bearings. For the migration route of most birds is not 

 directly north and south, and many preface their 

 southerly journeys by long flights directly east or west. 

 The bobolinks and vireos of the northwestern states, for 

 example, leave the country by way of Florida or the Gulf 

 coast and first fly directly east to the Mississippi Valley 

 to join the others before starting southeasterly. The 

 white-winged scoters which nest about the lakes of cen- 

 tral Canada, upon the completion of their nesting duties, 

 fly directly east and west to the Atlantic and Pacific 

 where they winter. Some herons preface their migra- 

 tions by long flights, even to the north, so that occasion- 

 ally little blue herons and egrets are found in the north- 

 ern states during August and September. 



