Identifier: handbookofbird00chap (find matches)
Title: Handbook of birds of eastern North America; with introductory chapters on the study of birds in nature
Year: 1912 (1910s)
Authors: Chapman, Frank M. (Frank Michler), 1864-1945
Subjects: Birds
Publisher: New York, London, D. Appleton and Company
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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is obvious that the significance of the colorsof eggs can be ascertained only by a study of them where they werelaid. Sha-pe of Eggs.—Birds eggs are usually ovate, but may be ellip-tical, spherical, pyriform or conical. The pyriform egg of the Murre,when moved slowly, describes a circle about its own point, and istherefore less apt to roll over the narrow, rocky ledges on which Murresusually lay, than an oval egg. The conical eggs of Snipe and Ploverare placed in the nest point downward or inward, thus fitting togetherso closely that they can be easily covered by the comparatively small-bodied parent. Thus with form, as with color, it is clear that the eggshould be studied where the bird placed it. Variations.—Although, generally speaking, the eggs of the samespecies resemble one another, there is a wide range of variation in color,size and shape, and to a lesser degree in number. Doubtless these varia-tions are in the main an index of the physical condition of the bird Plate III
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Eggs of Meadowlark and Upland PloverSize of eggs in relation to condition of young birds when hatched. Note that, whilethe birds are of about the same size, the eggs of the Meadowlark, an altricial bird, aremuch smaller than those of the Upland Plover, a prajcocial bird. ■^^ m ^ ^ ^^^^^^^r^«V ^ ^ ^^ Eggs of Common Tern Collected in a small colony on an island in Shoal Lake, Man., to show variation in color and pattern. I THE YOUNG BIRD 79 concerned. Fully adult, vigorous birds probably lay larger and moreheavily pigmented eggs and more of them than their younger or weakerfellows. Again, the first eggs of a set, as well as those of first sets, wheremore than one is laid, may be more strongly pigmented or larger thanthose laid later. But whatever their cause, the cataloguing of thesevariations constitutes no small part of the labors of the oologist, whosedelight in finding an unusually large set, or one containing runt eggs,or colored eggs which should be plain, or plain eggs which s

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