REED WARBLER 



growth of the reeds from year to year in the second week 

 of May in this country is slight, and does not appear to me 

 to be sufficient to influence their movements. Moreover, it 

 is not possible for a species in a foreign land to be cognisant 

 of the state of growth of the reeds in these islands. If it 

 can be shown that there is any relation betw r een the two, 

 an explanation must be sought in some peculiar climatic 

 conditions which, while delaying the departure of the 

 migrants, would at the same time retard the growth of 

 the reeds. In Hungary I found these birds plentiful in the 

 year 1905 on April 26th, and there is little doubt that they 

 had already been there some time. On the other hand, I 

 have no records of their arrival in this county earlier than 

 May 1st. In the year referred to, the growth of the reeds in 

 Hungary was undoubtedly in advance of the growth in this 

 country. So that before we attempt to understand this 

 question of migration, w T e must be in a position to decide 

 whether, on the average, the same individuals migrate to the 

 same country year after year. There are some grounds for 

 believing that they do so, for it is clear that those individuals 

 that reach Hungary about April 20th must have commenced 

 their journey some time before those that reach this country 

 during the first week in May. 



Both males and females arrive throughout May and part 

 of June, even as late as the 21st of the latter month. But 

 it is by no means unlikely that some of the individuals are 

 not " arrivals " in the sense of having only completed their 

 journey that particular day. Indeed, it is impossible to 

 distinguish between a male moving from pool to pool seeking 

 territory, or similarly a female in search of a male, and a 

 true arrival, that is to say, a bird that has only comparatively 

 recently commenced to travel from its winter home. These 

 later arrivals may not, therefore, be migrants in the narrower 

 use of the term, but only individuals unsuccessful so far as 

 reproduction is concerned. Yet it is well-nigh impossible to 

 decide this by actual observation. Their plumage has no 



