396 USEFUL BIRDS. 
glass. I have often thus watched Bluebirds and Chickadees 
feeding their young. 
Thus far it has been my intention to show how expense may 
be avoided in the construction of nesting boxes. Neverthe- 
less, expensive ornamental bird houses add to the attractive- 
ness of a country home, and may be displayed where old tin 
cans and cheap boxes 
would be out of place. 
In building such bird 
houses the best plan is 
to imitate the design 
of some dwelling. A 
pretty cottage ora 
country villa may be 
constructed in minia- 
ture. The large bird 
houses sometimes made 
are highly ornamental ; 
but most of our native 
species are not social in 
‘their nesting habits, and 
when a large house is put up it is likely to be occupied either 
by a single pair of birds or by Purple Martins or House 
Sparrows. Such houses are sometimes occupied by both 
Martins and Sparrows, but in such cases the Sparrows usu- 
ally in the end drive out the Martins. Ifthe Sparrows can be 
driven away, there is no bird that can be so readily increased 
in numbers by putting up nesting boxes as can the Purple 
Martin. When once a colony of Martins becomes estab- 
lished, it will in a few years fill several large bird houses 
with its increase. The experience of Mr. J. Warren Jaccbs, 
who established a large colony, illustrates this.| A few Mar- 
tins are returning to some of their old homes in this State ; 
they should be encouraged. The houses should be either 
taken down in fall and not put up until the Martins return 
in spring, or the entrances to the rooms should be closed up 
until spring, that the Sparrows may have no opportunity to 
get in before the Martins return. Were the Sparrows de- 
Fig. 169.— A Martin box. 
' The Story of a Martin Colony, by J. Warren Jacobs, Waynesburg, Pa. 
