49 



There has always been a difference of opinion as to the cleani'iig 

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

 to clean the boxes. That may have been tlie 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 non in use — 

 a faithful copy of natural w^oodpecker holes — are at once fearlessly 

 occupied bj^ 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 they 

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

 should not hesitate to clean the boxes where possible. 



It is, of course, often impossible to do this, as A\hen 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 ^vith a key and afterwards tightened 

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

 this treatment. 



I cannot therefore recommend the cleaning of boxes everywhere 

 and unconditionally. 



On the Seebach experimental station only those boxes are cleaned 

 which are ojDcned for inspection. Tjie others are not cleaned. 



The cleaning need only be superficial, of course. It consists chiefly 

 in removing the rougher portions of the old nest, or anything that 

 may interfere with birds settling there. In this way sufficient old 

 mould remains in the trough, so that none need be added. If bats 

 have taken possession of the boxes, they should not be disturbed. 

 They are as useful as the birds. The boxes are fulfilliag the purpose 

 for which they were hung. Ne^^' 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 



