INTRODUCTION
This is the twelfth in a series of bulletins of the United States National Museum on the life histories of North American birds. Previous numbers have been issued as follows:
- 107. Life Histories of North American Diving Birds, August 1, 1919.
- 113. Life Histories of North American Gulls and Terns. August 27, 1921.
- 121. Life Histories of North American Petrels and Pelicans and their Allies, October 19, 1922.
- 126. Life Histories of North American Wild Fowl (part), May 25, 1923.
- 130. Life Histories of North American Wild Fowl (part), June 27, 1925.
- 135. Life Histories of North American Marsh Birds, March 11, 1927.
- 142. Life Histories of North American Shore Birds (pt. 1), December 31, 1927.
- 146. Life Histories of North American Shore Birds (pt. 2), March 24, 1929.
- 162. Life Histories of North American Gallinaceous Birds, May 25, 1932.167. Life Histories of North American Birds of Prey (pt. 1), May 3, 1937.
- 170. Life Histories of North American Birds of Prey (pt. 2), August 8, 1938.
The same general plan has been followed, as explained in previous bulletins, and the same sources of information have been utilized. The nomenclature of the 1931 check list of the American Ornithologists’ Union has been followed, but it has seemed best to continue in the same order of arrangement of families and species as given in the old check list (1910).
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.
Through the courtesy of the Bureau of Biological Survey, the services of Frederick C. Lincoln were again obtained to compile the distribution paragraphs. With the matchless reference files of the Biological Survey at his disposal, his many hours of careful work have produced results far more satisfactory than could have been attained by the author, who claims no credit and assumes no responsibility for this part of the work.
Dr. Winsor M. Tyler rendered valuable assistance in reading and indexing, for this group, the greater part of the leading periodicals relating to North American birds, which saved the author many hours of tedious work and for which he is very grateful. Dr. Tyler contributed the life histories of the northern downy woodpecker and yellow-bellied sapsucker, Dr. Arthur A. Allen wrote the life history of the ivory-billed woodpecker, Bayard H. Christy that of the northern pileated woodpecker, and Dr. Eugene E. Murphey that of the red-cockaded woodpecker. Thanks are due also to F. Seymour Hersey for figuring the egg measurements.
The manuscript for this volume was completed in June 1938. Contributions received since then will be acknowledged later. Only information of great importance could be added. The reader is reminded again that this is a cooperative work; if he fails to find in these volumes anything that he knows about the birds, he can blame himself for not having sent the information to— The Author.