DISTANCES TRAVELLED BY BIRDS 73 



his reference to this being roughly in the same 

 latitude but reached by a different " line of flight," 

 suggests that it is an exception ; this will be shown 

 when some hundreds more cases have been col- 

 lected. It may, however, be found that some birds 

 deliberately launch forth in search of new homes, 

 though at present it looks more like a bird which 

 on approaching the breeding area had banded itself 

 with the wrong local body of travellers. 



A bird marked at Cassel in western Germany has 

 been recorded from Barcelona in Spain ; this so far 

 single record may indicate that storks get lost, that 

 there is no regular direction, or that there is more 

 than one, a south-westerly as well as a south-easterly 

 route. That too, we hope, will be shown in the 

 future. 



That much will be learnt from storks is evident, 

 but the lessons will be only general ; each migratory 

 species must be treated separately, and to some 

 extent this is being done. In the opening chapter 

 I mentioned the uncertainty about the behaviour 

 of any individual song thrush, merely as an example. 

 So far, the few records of marked song thrushes add 

 to rather than solve this problem. Years ago the 

 song thrush was looked upon as a permanent resident 

 so far as Britain was concerned. Then it was found 

 to be migratory even in Britain, and it was sug- 

 gested that each song thrush performed a short 



