394 USEFUL BIRDS. 



ter being made a little larger. The Flicker will sometimes 

 enter a knothole, only two and one-half inches in diameter, 

 in an old apple tree ; but if so small an opening is made in 

 a box put up for this bird, it may not use it. For a Flicker 

 or a Screech Owl the entrance should be made at least three 

 or three and one-half inches in diameter. 



In making boxes of the form illustrated as the cat-proof 

 box (Plate XL VII, Fig. 4), the following inside dimensions 

 are sufficient. Boxes for Wrens or Chickadees may be made 

 twelve by four by five inches, with the entrance hole close 

 to the top. They may be placed from six to twenty-five 

 feet from the ground. 1 A perch is not necessary. Boxes for 

 Flickers are best if made from hollow limbs or covered with 

 bark. These birds do not need perches. If limbs with the 

 bark on are used, they should be cut in late summer, autumn, 

 or early winter, when the bark will adhere. A box for a 

 Flicker may be eight by ten by fifteen inches, and should be 

 placed from six to twenty-five feet up. A similar box twelve 

 inches square and fifteen high would be ample for a family 

 of Screech Owls. 2 A box twelve by five by six inches is 

 ample for Swallows or Bluebirds, and should be placed from 

 twelve to thirty feet from the ground. Swallows and Blue- 

 birds like perches. The long diameter of the box should 

 be from front to back. The sitting bird will then face the 

 entrance, a good position for defence. A single tene- 

 ment will accommodate a family of Martins, but a colony 

 of these birds should be secured, if possible. 



Some writers have recommended putting up boxes with 

 the entrance facing the east or north. This may be right in 



1 The distances from the ground as given here are not arbitrary. I have known 

 the Chickadee, for instance, to nest at different heights, from two to fifty-five 

 feet from the ground. 



2 This size of box is probably none too large for the Screech Owl, as three or 

 four young birds soon render the edges of the nest very filthy, and on this ac- 

 count probably require extra room. Nevertheless, a pair of Screech Owls at our 

 home in Wareham reared a brood of four young in the grocery box shown in the 

 upper figure on Plate XLVIII. Allowing the birds to be the best judges of what 

 they want, the dimensions of this box, seven by eleven by fifteen inches, and the 

 size of the entrance, three by four inches, may be useful to those who wish to at- 

 tract this bird. It was noted that during the daytime, at least, the mother Owl in 

 this box always sat with her head away from the entrance, and in the darkest 

 corner, an incubating position sometimes assumed by the day birds that nest 

 in boxes. 



