49 



There has always been a difference of opinion as to the cleaning 

 of the nest-boxes. Professor Liebe thought that it was actually harmful 

 to clean the boxes. That may have been the case with the unnatural 

 boxes of those days. A comparatively long time always elapsed 

 before such a box was used at all. It had to become old and the 

 birds had to grow used to it. This was undoubtedly simplified if it 

 contained an old nest. 



We have changed all this. The von Berlepsch boxes now in use 

 a faithful copy of natural woodpecker holes are at once fearlessly 

 occupied by all birds, even when quite new. and experience has shown 

 that the last hung up and the newest are preferred. The old nest 

 is therefore no longer required for the above purpose. But as some 

 nesting boxes are lost for the next breeding season because the;y 

 contain dead birds, insects, or something that the bird dislikes, we 

 should not hesitate to clean the boxes where possible. 



It is, of course, often impossible to do this, as when boxes C and D 

 and probably B are hung too high, when there are too many, or when 

 there is no competent person to carry out the work. 



The boxes must be opened for cleaning, and for this purpose the 

 screws of the lid must be loosened with a key and afterwards tightened 

 again. It is very likely that more harm than good will result from 

 this treatment. 



On the Seebach experimental station a new method of hanging up 

 the boxes is being tested, which will enable us to take them down 

 and hang them up again at will. The favourable results hitherto 

 experienced will probably lead to the general introduction of this 

 arrangement, which will make a thorough cleaning much easier. 



When the boxes are cleaned the bottom layer of mould ought also 

 to be removed, as it is there that mites and other vermin chiefly collect, 

 but it must be replaced in accordance with the measurements given on 

 pp. 43-4. If bats have taken possession of the boxes, they should not be 

 disturbed. They are as useful as the birds. The boxes are fulfilling 

 the purpose for which they were hung. New boxes must be hung beside 

 them. 



(H) Successful results of the Berlepsch Nesting-boxes. 



Wherever these nesting-boxes have been hung up a great success has 

 been the result. All the breeders in holes (see p. 30}, and for the last 



D 



