CHAPTER XV 

 AIDS TO NESTING 



a. Nesting-boxes 



Von Berlepsch Type. Many years ago Baron von Ber- 

 lepsch began his careful experiments to ascertain what sort 

 of artificial nesting-hollows, if any, would best attract birds. 

 Examination of chambers dug by woodpeckers and others 

 revealed the fact that they were all made on one plan. Be- 

 ginning with an entrance barely large enough to admit the 

 bird, the tunnel broadened out in the form of a pear, and 

 narrowed again at the bottom, so that, while there was room 

 for the parent to sit, the eggs tended to roll together in the 

 centre. After further effort the Baron was able to have 

 sections of natural branch excavated by machinery to re- 

 produce exactly the tunnels of woodpeckers of different 

 sizes. When he put them up in surroundings such as the 

 feathered builders would have chosen, the birds did not 

 perceive any difference from what they were accustomed to, 

 and from the start took possession in good and increasing 

 numbers. 



Use in America. Here in America for a time these hollow- 

 limb nest-boxes were imported from Germany. It proved 

 expensive to do this, and various efforts were made to make 

 machinery here which would do the work. This has now 

 been accomplished, and such boxes, "made in America," 

 are now on sale. They are made in six sizes, for wren, nut- 



211 



