PLAN OF BOOK 
3 
Following, in smaller type, are the more common local names by which 
the species is, or has been, known in various localities; the French name is 
also given in this type. 
The Latin specific name follows in italics and is always binomial. 
In the treatment of subspecies, species have been treated as aggre- 
gations of subspecies, each of equal rank and importance, and not, as is 
customary, as species with subordinate subspecies dependent upon them. 
The species is first given as a whole, including its subspecific races, and, 
under a subhead, mention is made of the special subspecies that occur 
within the geographical scope of the work. 
Preceded by the initial “L” the average length of individuals of the 
species is next given in inches and decimals of an inch. The length of a 
bird is determined by measuring it, in the flesh, in a straight line from the 
tip of the bill to the end of the longest tail feather, the bird being stretched 
only enough to straighten the neck curves. The measurements given are 
those of the average adult male. They are generalized indications of 
comparative size and are not always to be relied upon for exact specific 
identification, as in most species there is more or less individual and sexual 
variation. 
Only an outline description of species is given, and where there are 
illustrations the description is omitted and the reader referred to the 
illustration. 
Under “Distinctions” an attempt is made to bring out the salient 
points by which the species, when in hand, may be distinguished from 
other similar forms. In this attempt the work of other authorities has 
been freely drawn upon to supplement the writer’s observations. Many 
of the distinctive points, naturally, are only superficial, but all, so far as 
possible, are reliable. 
Linder the head “Field Marks” the features by which the species may 
be recognized in life are mentioned. In these the writer has been guided 
largely by his own experience and has stated the points that seem to him 
most characteristic. For species with which he has had little experience 
in life he has relied upon other authorities, 
“Nesting” is merely a brief description of the nest and its situation. 
Much of this is drawn from other authors. 
Under “Economic Status” is given a summary of present knowledge 
of the species in its relation to man. Most of this is drawn from the 
admirable work done by the United States Biological Survey. Of necessity 
only a brief outline of the data upon which conclusions are founded can 
be given, and the reader is referred to the section on Ornithological Liter- 
ature for the titles of books and articles that afford further details. 
Under “Distribution” it has been deemed best to give the distribution 
in such general and well-understood terms that all may get at least a general 
conception of the ranges of the species. The result may be a little vague 
owing to the lack of sharply defined boundaries of the ranges, but the 
centres of distribution are made clear. For definite ranges the reader is 
referred to the “Catalogue of Canadian Birds” by John and James M. 
Macoun, issued by this department in 1909. 
In the paragraphs in larger type as many facts of general interest 
relating to the species have been included as the importance of the species 
warrants. The descriptions of the various species include discussions of 
numerous matters and statements of general laws governing zoological 
