THE AUTUMN MIGRATION OF BIRDS. 235 



Although the fact may not be so apparent as in 

 spring, each species has its regular time of migration 

 in autumn, to which it keeps with wonderful punc- 

 tuality. Almost to the day birds may be missed in 

 autumn just as we may look for them to arrive on a 

 certain date in spring. This rule, however, can only 

 be strictly applied to adults ; the young birds 

 migrate either as soon as they can fly, or begin to 

 wander from their birthplace as soon as they can 

 feed themselves. The movement is generally in 

 the direction of the usual migration. Birds appear 

 very regularly at certain points en route in autumn, 

 but generally in more variable numbers than in 

 spring. It is also worthy of remark that the young 

 birds in certain northern species, especially in 

 Nomadic Migrants, wander the furthest south. 

 Everywhere young birds seem possessed more or 

 less with a mania for wandering about. Some of 

 the most extraordinary instances of birds occur- 

 ring far from their usual habitat, have been 

 those of young or immature individuals — as if on 

 the look-out for new haunts in which to settle ; 

 and this, combined with the ordinary migratory 

 impulse, often sends them far from their usual 

 area. 



As in the preceding chapter, the following table 

 will give some idea of the Migration of birds 

 in Autumn, the same species being selected to 

 illustrate the return journey. As previously re- 

 marked, however, the winter quarters of the House 

 Martin are very imperfectly known : — 



