The publication contains all the species known to ornithologists at the time. The numbers of many of these species were already in decline, leading Elliot to predict in the Preface that some would soon become extinct from North America.

“In choosing a family of birds for a second Monograph, I was induced to make a selection of the Tetraoninae, not only on account of their varied forms and interesting habits, but also for the important part they bear toward man’s comfort and happiness. Although not brilliant in plumage of varied colors, like the Pittidae, still few could witness the graceful forms, erect carriage, and gallant bearing of the members of this family, without having their admiration excited. The majority of the species are inhabitants of North America, and many of them, through the continued persecution to which they are subjected, and the want of a rigid enforcement of proper laws for their protection, are rapidly disappearing from our land, in a comparatively short space of time to become extinct; and this was an additional reason to write their history while they were still to be found, and their habits observed in their native wilds.”