4 
INTRODUCTION 
life. Many of these apply to a number of species and some might well be 
included under each specific heading were it not for the constant repetition 
that it would necessitate. An attempt has been made to encourage a 
wholesome protective attitude from esthetic, humane, and economic 
points of view without over-emphasizing any of them. 
Throughout it has been the endeavour to avoid the use of technical 
terms, substituting familiar words wherever possible. Some technical 
terms, however, have no general vernacular equivalent and a glossary of 
these is given. 
ACKNOWLEDGMENTS 
The writer reiterates his acknowledgment of indebtedness for all the 
valuable assistance individually acknowledged in the Birds of Eastern 
Canada and the Birds of Western Canada and thanks numerous corres- 
pondents and advisors who have since assisted in bringing information up 
to date. A number of new coloured plates are included in the present 
volume and numerous additional text figures. The coloured plates are 
from the brush of the Museum's bird-artist, Allan Brooks, the text figures, 
with the exception of those in the “Key” by Claude Johnson, are from 
the pen of the writer. 
CLASSIFICATION 
The present system of generic grouping of species was first advanced 
by Linnaeus in his epoch-making “Systema-Naturae” and has since been 
followed consistently by zoologists. By this system species are grouped 
together in genera according to fundamental structural relationships and 
not accidental resemblances. The fact that upon the discovery of the laws 
of evolution these relationships were found to agree with lines of descent 
proved the logic of the system and gave it an added meaning. Thus the 
various specific members of a genus may be conceived as having descended 
from a common specific ancestor; the genera of a family from a common 
generic ancestor, etc. 
Existing North American birds may be divided into a number of 
Orders, the largest groups with which the Canadian ornithologist has 
direct concern. Orders are divided into Families , Families into Genera, 
and Genera into Species. These divisions may be again subdivided into 
Suborders, Subfamilies, Subgenera, and Subspecies , whose positions in the 
scheme are evident from their titles. 
Though the limitations of book construction necessitate linear arrange- 
ment of the classification scheme as a succession of forms following one 
another in single file, it should be borne in mind that the system is not 
linear in conception. The component species, instead of following a single 
line of relationship and sequence from the lowest to the highest, present 
many parallel or divergent lines of equal or subordinate rank. The class 
Aves or Birds may be represented by a tree, the height of the tree represent- 
ing time in geological ages from the earliest at the bottom to the present 
near the top. The trunk should be double at the base; one stem a short, 
dead stump to represent the fossil, toothed birds which became extinct 
before present geological time; the other, large and thrifty, to represent 
the modern, untoothed forms. The latter should divide a short way from 
the base into two main branches to represent the two subclasses, the raft- 
breasted and the keel-breasted birds. The former would be represented by 
much the smaller branch, whereas the latter would divide and subdivide into 
branches representing orders, next families, then genera, and finally species. 
