BIRD MIGRATION. 1 3 



Starting southward. The younger birds would naturally follow straggling 

 after, but all keeping the same general direction and in sight or hearing of 

 one another, precisely as they do by day when scattered about in woods, 

 thickets, or fields. 



It is not necessary to assume, nor in my opinion is it likely, that these 

 flocks keep intact throughout the whole of their long journey. During even 

 its earlier stages, their members must become by turns separated from one 

 another and associated with birds of the same or different species belonging 

 to other flocks which may have started from various localities, but which 

 are travelling in the same direction and along the same or parallel paths.* 

 But whether among friends or strangers, the contagion of example would 

 not fail to act on every favorable occasion, at least as long as old birds were 

 present. Moreover, the young would quickly learn to start without such 

 leadership, and, once in the air, straggling parties and individuals would 

 soon fall in with the general tide of migrants flowing ceaselessly overhead. 

 Thus the force of example would continue to direct, after it was no longer 

 needed to incite, these noctui-nal flights until the final destination was 

 reached. 



All animals have a strongly developed sense of locality and direction. 

 They observe keenly, and readily recognize places and landmarks which 

 they have seen before. Hence it is not surprising that birds quickly learn 

 to follow a path, even for thousands of miles, along which they have been 

 in the first instance led by older companions, and the young bird after a few 

 seasons would become an experienced guide. 



It may be asked in this connection how the various species which start 

 together or join one another during the early stages of the journey, separate 

 again, as must be the case, when they reach a point beyond which 

 their routes diverge. An answer to this question was suggested at Point 

 Lepreaux by the fact that, while many species of birds arrived together on 

 the same night, and mingled indiscriminately in the neighboring woods 

 during the tbllowing day, they did not invariably depart together or in 

 exactly the same direction. This leads me to believe that similar places 

 along every route constitute what may be called stations or points of 

 departure. At such places — ordinarily promontories extending into the 

 sea, points of timber bordering extensive plains, or the extremitj'' of moun- 

 tain ranges — the migratory tide hesitates and halts before venturing on the 

 dangerous stage ahead, and (as we know to be the case) birds of various 

 species quickly collect, often in extraordinary numbers. This pause allows 

 the stragglers to come up, and when the host again starts, the different 



* That this is really the case is shown by the frequent association during migration of species 

 which we know must start from widely different localities. 



