1919- BURKITT. — Song and Nesting of Birds. 101 



There were a good many singers (query mateless) over the 

 country on the ist July, but none a week later. The indica- 

 tion (if of any value) from these Willow-wren observations 

 would be that the males practically cease to sing very 

 shortly after mating ; and that, therefore, those males 

 which continue in full song are mateless. The late com- 

 panion of E and the very late ones of A, B, F, if they really 

 were mates, correspond to what occurs to the Whitethroats 

 (see my article referred to). But does anyone know of 

 Willow- wren nests in July ? 



As to Sedge-warblers, and any deduction to be got from 

 their singing, there is not much to say according to my 

 observation. I had six or seven cases under observation, 

 of which three included nests. 



I selected fairly isolated cases. The result of my notes, 

 which I need not detail, is that the Sedge- warbler sings more 

 or less during the whole season. But I was surprised how 

 little gratuitous song there was. Of course the male will at 

 all times sing a little on disturbance. But the only con- 

 siderable free singing was on arrival, before mates had been 

 met or selected, and again about the ist July, when 

 they gravitated to form communities in the sedge areas or 

 meadows or oats. About the middle of July they get again 

 silent, though sometimes a song is heard till the end of the 

 month. I cannot say that the July singing is because of 

 second broods, as I did not notice isolated second-brooders 

 singing. I think many of them have second broods. In 1918 

 I found a bird on three eggs (one chipped) as late as August 

 2nd, and plenty of young seem to be in the nest till that date. 

 Both parents feed the young. 



I might start a table as under : — 



Whitethroat . . Song ceases . . Later songsters mateless. 



Garden Warbler . . Song ceases . . Later songsters mateless ? 



Willow-wren . . Song ceases ? . . Later songsters mateless. 



Male does not feed ? 



Grasshopper Warbler Song ceases . . Male also feeds. 



Chiffchaff . . Song continues . . Male does not feed. 



Wren . . Song continues . . Male does not feed. 



Sedge Warbler . . Song indefinite . . Male also feeds. 



Enniskillen. 



