An attempt has been made to give as full a life history as possible of the best-known subspecies and to avoid duplication by writing briefly of the others and giving only the characters of the subspecies, its range, and any habits peculiar to it. In many cases certain habits, probably common to the species as a whole, have been recorded for only one subspecies; such habits are mentioned under the subspecies on which the observations were made. The distribution gives the range of the species as a whole, with only rough outlines of the ranges of the subspecies, which cannot be accurately defined in many cases. The egg dates are the condensed results of a mass of records taken from the data in a large number of the best egg collections in the country, as well as from contributed field notes and from a few published sources. They indicate the dates on which eggs have been actually found in various parts of the country, showing the earliest and latest dates and the limits between which half the dates fall, the height of the season. The plumages are described in only enough detail to enable the reader to trace the sequence of molts and plumages from birth to maturity and to recognize the birds in the different stages and at the different seasons. No attempt has been made to describe fully the adult plumages; this has been done very well in the many manuals and State bird books that are now available. The names of colors, when in quotation marks, are taken from Ridgway’s Color Standards and Color Nomenclature (1912), and the terms used to describe the shapes of eggs are taken from his Nomenclature of Colors (1886). The boldface type in the measurements of eggs indicates the four extremes of the measurements. Many of those who contributed material for previous bulletins have continued to cooperate. Receipt of material from more than 430 contributors has been acknowledged previously. In addition to these, our thanks are due to the following new contributors: Dean Amadon, E. R. Forrest, Allen Frost, J. J. Hickey, Joseph Janiec, Melvin Johansen, M. B. Meanley, Jr., R. L. Meredith, E. E. Murphey, A. G. Nye, Jr., R. T. Orr, R. S. Palmer, Cordelia J. Stanwood, Wendell Taber, A. E. Thompson, and Mrs. L. J. Webster. If any contributor fails to find his name in this or in one of the previous lists, the author would be glad to be advised. Egg measurements were furnished especially for this volume by Dean Amadon, A. M. Bailey, C. E. Doe, J. R. Gillin, W. C. Hanna, H. L. Harllee, R. C. Harlow, R. T. Orr, J. H. Riley, G. H. Stuart, 3d, and Miss M. W. Wythe.