MIGRATIONS AND NESTING HABITS. 279 



Timid birds, or the smaller birds, as the wrens and 

 the vireos, travel by night and feed by day. Bold, strong- 

 winged birds as the robins, the blackbirds, and some of 

 the larks fly by day or night, can go long distances, and 

 so can afford to stop sufficiently long where food is 

 abundant. In good weather, migrating birds fly high, 

 and often follow some guiding feature of the landscape, 

 a river line, particularly, with its promise of food and 

 water; though they seem also to be guided by mountain 

 chains. There is little doubt that coast lines are a large 

 factor influencing birds in their migrations. Usually 

 fogs or storms bring them lower, probably to seek addi- 

 tional guiding features of the country over which they 

 may be passing ; though it is true that sight alone will not 

 suffice to explain all the marvelous activities which we 

 witness across the country every spring and autumn. 



Whatever the guiding sense may be, old birds seem 

 to possess it in greatest perfection. It is likely that 

 many young birds making the trip for the first time 

 fall by the way; but those who survive have "learned 

 how" by the next year; and thus a permanency of 

 leadership is kept up which becomes a strong factor in 

 the continuance of the life of the individual within 

 the species. Whatever the sense by means of which 

 the birds maintain their direction of movement toward 

 a fixed point we call it orientation fog seems to produce 

 much the same effect upon them as it does upon us, when 

 it shuts out the familiar landmarks. Man, as a traveller, 

 is perhaps the most helpless of all animals. Before the 

 invention of the compass, he stayed close home; and it 

 was indeed a hardy soul that ventured on the sea far 

 from the home shore. Blind-folded, he travels in a 

 circle; or lost on a plain, he travels again and again the 



