CHAPTEH III. COLORS OF BIRDS.* The almost endless range of variation in the colors and pattern of coloration of birds' plumage has attracted the attention of many philosophic naturalists. Why, for example, should birds from some regions always be darker than those from other regions ; why should ground-inhabiting birds generally wear a dull or neutral tinted costume ; and why should the male, with few ex- ceptions, be brighter than the female ? For answer I will outline some of the leading facts and theories in connection with this interesting subject. In the first place, however, it will be necessary for us to have some idea of the extent of individual change in color, that is, the various phases of color, which a bird may pass through during different periods of its life.f
- Consult Poiilton, Colors of Animal? (D. Appleton & Co.). Gadow,
■ in Newton's Dictionary of Birds— articles, Color and Feathers. Bed- dard, Animal Coloration (Macmillau Co.). Keeler, Evolution of the Colors of North American Land Birds ; occasional papers, California Academy of Sciences (San Francisco), iii, 1893. Also Allen, reviews of last two works. The Auk (New York city), x, 1893, pp. 189-199, 373-380. Allen, Alleged Changes of Color in the Feathers of Birds without Molting ; Bulletin of the American Museum of Natural His- tory. New York city, viii, 1896, pp. 13-44. Chadbourne, Individual Dichromatism in the Screech Owl ; The Auk, xiii, 1896, pp. 321-325, and xiv, 1897, pp. 33-39, one plate. f The term color, as here used, means practically the plumage or dress of birds, 35
