_Material_
[Illustration: Illustrated capital W]
Wood is the material par excellence for the bird house, the only
material which can be unreservedly recommended. Substitutes have been
used with varying degrees of success or failure. What glass is for the
window, wood is for the bird house. First, the birds are habituated to
it. It is a good nonconductor of heat, it resists rain and extremes of
temperature, and it can be made to harmonize with its setting. Over a
long period of time it improves, rather than suffers, from exposure to
the weather.
Soft wood with straight grain, such as pine or spruce, is preferable. It
is easily worked, may be nailed with little danger of serious splitting,
and is sufficiently durable. Slab wood, with or without the bark, and
old fence-boards make the most generally effective bird houses. If new
lumber is used, it should be rough, not planed; whether rough or planed,
it should be treated with gray, olive, or dull brown stain of a medium
shade. There are numbers of suitable oil stains on the market. The stain
should permeate the grain of the wood, without actually coating it as
paint does. Thickness of the boards should not be far from 1 inch. If
slab wood is used, it may be anywhere from 3/8 inch at the edge, up to
about 2 inches in the thickest part.
Leave the matter of materials for the nest itself entirely to the birds.
Not only is it quite unnecessary to place twigs, straws, strings, or
even choice feathers or other fluffy bits on or near the bird house, but
such action tends actually to defeat its own purpose. The prospective
tenants often seem to regard these well-meant efforts as evidence of a
competitor who has the advantage of priority. This is especially apt to
be the case when the materials are placed inside the house. Birds will
sometimes steal nesting sites and even the raw materials of others but
may choose to avoid the clash which such piracy entails, provided there
are other sites and materials not too far to seek.
_Entrance_
There is always danger of the wood splitting when too large an auger
hole is attempted. Before assembling the bird house, make an entrance in
the front board. Start by drawing a circle the exact size of the
doorway-to-be. Then, just inside this circle, bore four holes at equal
intervals, using a bit not larger than 3/8 inch for the smaller
entrances; not larger than ¾ inch for the larger entrances. It will now
be not too difficult, by use of a keyhole saw or pocketknife and
wood-rasp, to remove the wood still remaining inside the drawn circle.
Placing the board horizontally in a vice will further insure against
splitting while the holes are being bored.
[Illustration: Plate II. The Best and Most Simple Form of Artificial
Nesting Site
With dimensions appropriate to the species, this is the most
generally attractive type of house for all species excepting the
Purple Martin. It is the type especially suited for the chickadee,
nuthatch, and Tufted Titmouse.]
1 THE BLOCK SAWED AROUND (TO DOTTED LINE) AND SPLIT IN TWO.
2 HOLLOWED OUT HOLES DRILLED FOR ENTRANCE AND FOR FASTENING PEGS.
3, 4, AND 5 SHOW THAT A NEST IS NOT DISTURBED BY OPENING HOUSE TO
INSPECT.
6 THE "ARTIFICIAL WOODPECKER HOLE" IN PLACE. NOTE FASTENINGS FOR
FRONT,--WOOD PEGS.
7 TOOLS FOR OBTAINING AND WORKING THE MATERIAL.
_Nails_
When a bird house is fastened to a support by the "toe-nail" method (by
driving nails at a slant through the sides and bottom), it is a good
point first to drill holes of the right diameter to fit the nails
tightly; otherwise splitting of the sides or bottom of the house may
result. Use flat-headed nails.
_Slabs_
When slabs are used in house-building, the upright pieces may be
fastened to each other, at intervals of several inches, with a wire
staple having ¾-inch prongs one inch apart. These should be on the
outside of the house, where rust will color them to conform with the
rustic wood.
_Facilities for House Cleaning_
For inspecting the nest and, at the end of the season, for cleaning out
the old nest material, the top or some other section of the house should
always be easily removable. Exceptions to this rule are houses for ducks
and other larger birds, for which the entrance may be large enough and
the depth not too great for all such purposes. Do not open a house in
the owner's presence. The more brief and infrequent your inspections,
the less they will disturb the birds.
_Position of Boxes_
Bird houses erected on poles are safer from predators than those placed
in trees. Houses for Purple Martins, in particular, need to be at a
distance from trees and buildings, and if possible near water.
Place your bird house where the sun will reach it during part of the
day, and turn the entrance away from the prevailing winds.
It seems hardly necessary to emphasize that, if possible, the bird
house, as well as the bird bath and feeding station, should be placed in
full view of a convenient window. To watch birds in their building and
other activities will prove a fascinating pleasure.
_Undesired Tenants_
The author once with complete success contrived and operated a
mechanical "bouncer" to meet a particular and aggravated instance of
bird trespassers. In case of interference with any desired tenant or
prospective tenant by rivals for the same bird house, the interfering
birds may be driven away by this device.
[Illustration: Figure 1. Discouraging the Uninvited Guest.]
One end of a stout cord is attached at some point close below the bird
house. To this cord a rag or a piece of waxed paper about
man's-handkerchief size is tied as conspicuously as possible at a
distance from the fastened end of the cord about equal to the height of
the bird house. The cord's free end is then carried through a window of
your own house from which there is a convenient view of the bird box.
The end of the cord is fastened inside the window where it can be easily
reached and jerked, enough slack being allowed to let the rag at the
other end hang down. If the unwanted birds appear on or too close to the
bird house, the cord is given a sharp pull which will cause the rag to
jerk upward and frighten the intruder away. Repeat as often as occasion
requires.
Care should be taken to work the bouncer when only the undesired birds
are within effective distance. However, should the contending birds
actually come to bodily grips on or beside the nesting site, the fight
may be broken up by vigorous operation of the alarm. The author found
that this device, exercised as occasion required, in two days ended a
week-old continuous struggle between a Bluebird and a pair of Tree
Swallows in which the Bluebird had entirely defeated the daily efforts
of the Swallows to start a nest. The Swallows were left in possession,
quickly built their nest, and duly raised their brood.
Obviously, this device and procedure may be applied against Starlings,
English Sparrows, or other birds, regardless of species, which for any
reason one desires to discourage from building in a given bird house or
other nesting-site.
The use of a rag or similar object, instead of a bell or other
noisemaker, is advised because the range of alarm is thereby limited to
the immediate location of the bird house, so that the desired tenants
will not be frightened by the operation of the alarm when they are
within hearing.
_Thickets_
"Reserves" of the favorite environment are as much a need for some
species as bird houses are for others. Widespread "improvement" and
"beautification" along roadsides is destroying the thicket, the favored
haunt of Song Sparrows, Catbirds, certain warblers, quail, and other
desirable species. A "reserve" thicket may be located in a secluded part
of the home grounds, hidden by a hedge if considered unsightly. It may
be almost any shape, but not less than 20 feet in average diameter or
much less than 400 square feet in area. Here weeds, tall grass, briars,
and dense bushes are allowed to grow wild, forming a tangle as they
will. If the bushes include such kinds as hackberry, hawthorn, sumac,
elderberry, and chokecherry, the thicket's annual period of usefulness
will be extended. Including such a winter food tree as the mountain ash
will invite Purple Finches, Pine Siskins, grosbeaks, waxwings, and
perhaps crossbills.