172 CONSERVATION OF CANADIAN WILD LIFE 
of birds that are an actual necessity in the maintenance of 
as great a control as possible over the infinite variety of 
insect pests that attack the roots, stems, branches, and 
leaves of our cultivated plants and trees. And whatever 
may be the habitat of the insect it is usually found by some 
species of bird owing to the diversity of their feeding-habits. 
In view of the great economic value of our insectivorous 
birds from an agricultural standpoint, but not forgetting 
the zsthetic motives which surely need not be supported 
by argument, it is evident that the protection of these birds 
must form an important part in the maintenance or in- 
crease of our agricultural production. 
Experience has shown that not only directly by killing, but 
indirectly by the destruction of their natural haunts and 
breeding-places, man has intentionally and unintentionally 
been more anxious to destroy bird life than to protect it. 
Leaving aside the wilful destruction which birds have suf- 
fered by their misfortune in offering an easy and living tar- 
get, we find that the former haunts of our birds are obliter- 
ated by the advance of agriculture and settlement. Wood- 
lands and forest are cut down and give way to open fields; 
bird-haunted snake fences yield to wire. Near our cities 
subdivisions and lots wipe out the waste places and wooded 
haunts of birds. With their breeding and feeding places 
more and more reduced, and their lives frequently endan- 
gered, it is not surprising that birds are not more abundant, 
- and that protection and encouragement are essential. 
Local Abundance of Birds.—Few people realize the variety 
of birds that breed within a certain area, as so many species 
are shy in their habits. During the last few years the Bi- 
ological Survey of the United States Department of Agri- 
culture has been conducting a bird census of the United 
States. As illustrating the valuable and interesting data 
that such a census provides, the following are the results of 
an annual census taken since 1914 by Mr. Norman Criddle, 
