78 JAMES SCHENK 



in autumn. Tlie hitherto practised banding experiments may scarcely be 

 sufficient to the satisfactory solution of the migration in spring and it 

 seems that the international stations for capturing and banding, like the 

 one of dr. Weigold on Helgoland, will be called for to supply us with 

 the deciding results. 



These stations for capturing and banding might especially ascertain the 

 hitherto missed results concerning the migration of small birds. In relation 

 to this I will only mention, that till now of the 9000 banded Chimney 

 Swallows (Hirundo rustica) and House Martins (Deliehon itrbica) not one 

 has been found outside the boundaries of the country. The present report 

 contains only the confirmation of the returning of the Chimney Swallow 

 to its native country. Just the same is stated about the common Swift 

 (Cypsehis apus), and the Wryneck (Jynx torquilla), whereas the Sparrow 

 (Passer domesticus), the Nuthatch (Sitta europea), the Titmouse (Parus 

 major), the Blue Titmouse (Partis caeridus), and the Marsh Titmouse 

 (Parus palustris stagnatillis) are, according to the results of the banding 

 experiment, stationary birds. 



Particularly to be mentioned, is a Blue Titmouse, which has been 

 captured and set free again since 5 years every winter at the same feeding 

 place in Eperj es. 



Though the results concerning the small birds, which have been 

 hitherto attained, are not refering to the migration, but to the dislocation 

 in the native country, they are not to be valued less, than those refering 

 to the migration, which often points out very distant districts as winter 

 quarters. I believe that our Institute was the first to point out the 

 importance of these dates to the Oecology of birds and I have on the 

 base of these dates proposed in the year 1915^) the law of the optimal 

 utilisaton according to which every individual of one species, is propagating 

 in the same place where it originated. Banding experiments, which have 

 been made elsewhere have confirmed this law, which has naturally also 

 exceptions. According to this law nevertheless the in-breeding of the bird 

 wowld be unavoidable, but in reality no symptoms of it are to be 

 remarked. 



How can these two facts be accorded one to the other? Perhaps 

 this first law has not the general validity, as one might be disposed to 

 beheve, on ground of the given dates. I throught as well to see a prevention 

 of the in-breeding in the circumstance, that for instance .in Hungary 

 according to the results obtained in Hungary, through systematical experi- 

 ments the Swallows are very often changing their mates, whereas a lasting 

 union is rather rare. Concerning this, there is still nuich work to be 



») Aqixila XXII. 1915. p. 274. 



