12 A GUIDK TO THE BIBDS 



ticHi of any one species Taiies, laigelj" according to the abun- 

 dance of the species, but also acoirding to some nnexplaiiiea 

 idiosjnoa&T of the bird. The Tellow-nrmped. "Warbler ii 

 passing thiongh sometimes for a period of ovei a month : the 

 Sist Bosty Blackbird often appears late in March, and the 

 last in earlj 3IaT. Certain tnids are seen much less £r»- 

 qnentlj in migration than one would expect fiom their abun- 

 dance noithiraid : the ^Vinter Wren and tiie Sapsucker are 

 examples. Some birds hare rerr different routes in spring 

 and fall : the Connecticut Warbler is almost never found in 

 Xew ^England in spriiK. but 15 sometimes locally common in 

 the autumn, irhile the Blackbumian Warbler is much rarer 

 in the autumn than in the spring. Several birds, therefore, 

 the TeHow-beUied Flycatcher and the Bay-breasted Warbler, 

 for iiiitiiioe. occur as not uncommon migrants along the 

 Hudson, or even in the Connecticut Valley, though rare in 

 eastern Xew England. 



The spring is an easier time to identify migrants than the 

 autumn, jlfearly all the males are in full song in the spring : 

 Tery fe\r sing at all in the autumn. Many birds change their 

 plulnage in the summer, and lose their bright distinctiTe 

 marks. And yet. to an enthusiast there is something very 

 fascinating in the study of the fall migrants. In spring, the 

 bird's song generally betrays his presence for some time be- 

 fore he is seen : but in the autumn one is kept constantly on 

 the alert to discover in the flocks of small restless trarUeis 

 or sparrows, often dull colored and puzzling, some novelty 

 or rarity. 



Perhaps the most interesting erperience connected wifli 

 the study of birds is to h^tr the notes of migrants pasi^ng 

 overhead on dear nights in August and September. The 

 tsip of Black-poll Warblers or the ekini of a Bobolink fall- 

 ing from the darkne^ brings home ";■ one with startling 

 impressiveness the ironder of the long journey from norUiem 

 ;^«'e'^ England to the Equator and back again. 



