A key to the Orders gives the more prominent characters on which they are based; telling for example, the external differences between a Duck and a Grebe. In comparatively few instances, however, will the beginner have much difficulty in deciding to what Order a bird belongs. Probably eight times, out of ten the unknown bird will belong to the Order Passeres, or Perching Birds, when one has only to select the color section in which it should be placed, choose from among the colored figures the bird whose identity is sought, and verify one's selection by reading the description of the bird's characteristics and the outline of its range.
In the case of closely related species, and particularly subspecies, the subjects of range and season are of the utmost importance. Most subspecies resemble their nearest allies too closely to be identified in life by color alone, and in such cases a bird's name is to be learned by its color in connection with its distribution and the season in which it is seen.
During the breeding period, unless one chance to be in a region where two races intergrade, subspecific names may be applied to the bird in nature with some certainty, for it is a law that only one subspecies of a species can nest in the same area; but during migrations and in the winter, when several subspecies of one species may be found associated, it is frequently impossible to name them with accuracy.
For example, during the summer one need have no hesitancy in calling the Robins of the lowlands of South Carolina the Southern Robin (Planesticus migratorius achrusterus) but later, when the Northern Robins (Planesticus migratorius migratorius) begin to appear, it would be difficult, if not impossible, to distinguish them in life from the resident birds.
If it were possible to impress the student, who proposes to name the bird in the bush, with the absolute necessity for careful, definite observation he would be saved many disappointing and discouraging experiences.
It is not possible to examine your bird too thoroughly. Never be satisfied with a superficial view and a general impression. Look at your bird, if you can, from several points of view; study its appearance in detail, its size, bill, crown, back, tail, wings, throat, breast, etc., and AT ONCE enter what you see in a note-book kept for that purpose. In this way, and this way alone, can you expect to compete with those who use the gun.
It does not follow, however, that because one does not collect specimens of birds one cannot study them scientifically. While the student may not be interested in the classification of birds purely from the standpoint of the systematist, he is strongly urged to acquaint himself with at least the arrangement of the Orders and Families of our birds and their leading structural characters.
To the student who desires to prepare himself for his work afield such a study may well come before he attempts to name the birds. But where the chief end in view is to learn a bird's name, the more technical side of the subject may be deferred. In any event, it should not be neglected. This orderly arrangement of knowledge will not only be practical benefit in one's future labors but it will bring with it that sense of satisfaction which accompanies the assurance that we know what we know.
As one learns to recognize bird after bird it is an admirable plan to classify systematically one's list of bird acquaintances under their proper Orders and Families. These may be learned at once from the systematic table at the end of the book, where the numbers which precede each species are arranged serially, and hence systematically.
In some instances, as an aid to identification in the field, descriptions of birds' notes have been included. It is not supposed that these descriptions will convey an adequate idea of a bird's song to a person who has never heard it, but it is hoped that they may occasionally lead to the recognition of calls or songs when they are heard.