72 THE WARBLERS 



comer, and although it is too rare and information on the subject too 

 scanty for definite assertion, yet it seems fairly clear from the careful 

 observations of Mr. W. Warde Fowler that the males do not arrive 

 until the last week in May, and the females a few days later. 



Whether or not the time for spring migration is made known 

 to birds by the natural promptings of the pairing season, the one 

 follows so closely on the other that when migrating birds arrive 

 in their breeding quarters they settle down at once to some detail 

 or other of this the most important business of the year. At any rate 

 no time is lost by the Acrocephali : directly the males arrive they find 

 suitable nesting places. It may be that they settle in the first suitable 

 place, or more likely return near to the neighbourhood where they 

 were reared. I do not think it is necessarily within very definite 

 limits, as it not infrequently happens that a locality may be inhabited 

 one year and deserted the next, and this without any alteration in the 

 natural conditions. 



In 1909 there were some five or six pairs of sedge- warblers, twelve or 

 fourteen pairs of reed- warblers, and a pair of marsh- warblers nesting in 

 a certain small overgrown osier-bed. In 1910 a diligent search resulted 

 in the discovery of a single pair of sedge-warblers, the sole repre- 

 sentatives of the genus. However this may be accounted for, the 

 choice of the nesting place rests with the males, as where they settle 

 on their arrival there they may be found throughout the season. 

 They spend the time prior to the arrival of the females in establish- 

 ing a claim to a more or less definite area, fighting and driving away 

 trespassers of their own species. The sedge-warbler is said to drive 

 away other species, even such as thrushes and hedge-sparrows. 1 



Resentment is, however, chiefly directed against others of their 

 own kind ; and as in the case of sedge- and especially reed-warblers 

 several nest in a comparatively small area, territories frequently 

 adjoin, and much squabbling results. 



While not occupied with these disputes, and searching among the 



1 Howard, British Warblers, Part I. p. 7. 



