178 CONSERVATION OF CANADIAN WILD LIFE 



their companions had gone during the winter and after 

 their breeding-time. Similar observations were made dur- 

 ing a plague of the same insect {Tortrix viridiana) in the 

 grand duchy of Hesse, where the protection of birds has 

 been carried on in a sensible and energetic fashion for over 

 ten years. Of 9,300 boxes hung up by the government in 

 the state and communal woods of the grand duchy of 

 Hesse, 70 to 80 per cent were occupied in the first year, and 

 in 1907 all were inhabited. On and near Baron von Ber- 

 lepsch's Seebach estate, 90 per cent of 2,000 nest-boxes in 

 one wood were occupied, and nearly all of 500 and 2,100 in 

 other localities. In Hungary similar measures are taken, 

 largely owing to the admirable work of Otto Hermann, one 

 of the foremost European advocates of bird-protection. 



Some years ago, when investigating the depredations of 

 the larch sawfly {Nematus enchsonii) in the English Lake 

 District, I was impressed with the value of birds as natural 

 means of control, and, as birds in the worst-infested district, 

 namely, Thirlmere, were not so abundant as they should 

 have been, it was recommended that they should be pro- 

 tected and encouraged by means of nesting-boxes. The 

 corporation of the city of Manchester owns Thirlmere, this 

 lake being their water supply, and they distributed nesting- 

 boxes of the pattern which I devised and which is illustrated 

 herewith (Fig. IV). The advantage of this box was that it 

 could be made out of the slabs or rejected outer portions of 

 the lumber bearing the bark. Three equal lengths of the 

 slab are nailed together to form three sides of a long box, 

 the outside of which, bearing the bark, was round and the 

 inside square. The fourth side is made of a flat piece of 

 wood forming the back of the box; this piece is longer than 

 the other sides, and projects above and below the box, 

 thus providing means of attaching the box to the tree. 

 The top and bottom of the box may be made of slab 

 wood. Several holes should be bored in the bottom, which 



