BRITISH WARBLERS 



worn or ragged appearance, but the colouring is brilliant and 

 the feathers in perfect condition, in striking contrast with 

 those birds that have actually commenced to breed some 

 weeks previously. The deterioration of the plumage is 

 coincident with, if not actually the direct result of, coition, 

 for it takes place very slowly when a bird is not breeding, 

 but rapidly immediately reproduction has commenced. Never- 

 theless evidence of a much more detailed character is necessary 

 before we can reach a final decision on this point. It even 

 appears to be more rapid in some species than in others, being 

 decidedly so in the case of this warbler, some individuals 

 commencing their moult early in July. So that we find, on the 

 one hand, members of the species arriving about June 20th in 

 perfect plumage, and thereupon commencing to breed, and on the 

 other, members commencing to moult early in July, having 

 finished the task of reproduction. Thus we have what appears 

 to be a curious irregularity, and one to which I shall refer 

 again. 



The Arunclo pTifagmites is the principal but not the sole 

 haunt of these birds, for they often frequent and build amongst 

 the various species of Salix that grow along the banks of 

 rivers, and on their way thither, or when in search of a terri- 

 tory, the males sometimes rest for a few days, or a few hours, 

 in such places as osier beds, or even amongst the shrubs in 

 gardens; but in such places they are merely sojourners, 

 although they sing as vigorously as if they were in possession 

 of a territory. They commence to sing on the morning after 

 their arrival, and as they are the most persistent of singers, 

 there is little difficulty in assuring oneself of their presence in 

 any particular reed bed. This is especially the case before the 

 females arrive, as they then sing almost incessantly through- 

 out the first few hours of daylight, commencing at dawn and 

 only lapsing into silence for short intervals. At this time of 

 day they can often be seen perched on some horizontal reed 

 pouring out their peculiar metallic sounding notes, or preening 

 their feathers, their attitude at such a time being much like 



