BIRD HOUSES AND HOW TO BUILD THEM. 
3 
The number of house birds may be still further augmented as time 
goes on. All of the commoner woodpeckers are likely to be included, 
as are several of the small owls and wrens, and a few of the wild 
ducks, as the golden-eye. The wood duck is already known to use 
nesting boxes. Houses set close to streams in the western mountains 
will probably bo occupied by ousels or dippers. Florida grackles 
sometimes breed in flicker holes and may be expected to occupy 
houses now and then. In every locality having trees there is a groui) 
of birds ready to appropriate houses when they have the opportunity. 
SUGGESTIONS FOR CONSTRUCTING HOUSES. 
House birds differ decidedly in their requirements. For those 
which usually excavate homes for themselves, the diameter of the 
entrance and the depth and diameter of the cavity must be in accord 
^vith their specific standards. Some birds are satisfied with almost 
any sort of a lodging. Bluebirds and wrens, for example, are con¬ 
tent to build in tomato cans, although chickadees and nuthatches 
disdain them. Wood is a better building material than metal or 
earthenware. Entrance holes should be countersunk from the out¬ 
side to exclude rain. Heads of nails and screws should be set rather 
deeply and covered with putty. All houses should be easy to open 
for cleaning. A perch at the entrance is unnecessary and may even 
be an objection, as it is frequently used by English sparrows while 
they twitter exasperatingly to more desirable occupants. To provide 
for proper ventilation a row of small holes is sometimes bored just 
beneath the eaves, but there should never be a ventilating hole 
lower than the entrance, and joints should be made tight, as drafts 
of air are dangerous. In case there is danger that rain may be 
driven in through the door, a small drainage hole, which will be 
covered by the nest, may be made in the middle of the floor. 
The appearance and durability of houses are improved by a coat 
of paint. A neutral shade of green or gray is suitable for houses 
mounted in trees, while those on poles, being conspicuously placed, 
lend themselves harmoniously to the landscape when painted white. 
The dimensions of nesting boxes shown in Table 1 are taken from 
the experience of successful builders and from measurements of 
woodpecker holes. 
