THE MARSH-WARBLERS 73 



herbage and on the ground for the various insects and other small 

 creatures which form their food, they freely make known their 

 presence by much singing, which nfay be taken as serving the double 

 purpose of advertising their claim to the spot, and guiding or attract- 

 ing the females when they arrive. Presuming that this is correct, 

 and therefore that their finding mates depends on the females being 

 attracted in this way, one wonders how they would proceed if after 

 due time their endeavours failed. Would they remain bachelors in 

 lonely possession of an eligible building site, or seek better fortune 

 in pastures new ? According to Naumann there is good reason to 

 believe that every year many reed-warblers remain unpaired. If this 

 is correct, failure on the part of males to attract female s might account 

 for it. 



Although the males will chatter and even break into song when 

 food-hunting, they make their serious vocal efforts when perched on 

 some favourite reed or bush untroubled by other cares save the 

 keeping of a watchful eye on trespassers. The sedge-warbler selects 

 not only a favourite bush but a particular branch on which to perch 

 whilst singing. Every morning in the spring and summer of 1908 I 

 passed a small island on the bank of the upper Cam. One morning 

 towards the end of April I heard the first sedge-warbler notes of the 

 year, and at the same time discovered the singer perched on a low 

 branch of a sallow bush. The next morning he was on the same 

 branch, and all through the nesting season I seldom missed him. 

 Sometimes only his call-note came from the herbage, but as a rule he 

 was on the old perch singing or preening his feathers. Towards the 

 end of May his song slackened considerably, but increased again late 

 in June and early in July, and although the bird was no longer to be 

 seen owing to the thick summer growth, the song generally came from 

 the direction of the original branch. Fragments of song were heard 

 as late as the 10th of August. 



The females are even more skulking than the males, for which 

 reason it is very difficult to know exactly when they arrive, or to see 



VOL. n. K 



