. Animal Life and the World of Nature; A magazine of Natural History. . GREY WAGTAIL. SOME INSTANCES OF COLOUR=PROTECTION IN BIRDS' EGGS. By C. H. Topham. TO the casual observer the many and varied colours of birds' eggs are meaningless, and do not suggest anything beyond their curious beauty; yet probably every one of these varied and numerous shades serves a definite purpose in nature, principally as a means of conceal- ment from the many enemies to which a bird at this early stage of its existence is exposed, in the same way that it is protected later on in life, when all birds assume such
. Animal Life and the World of Nature; A magazine of Natural History. . GREY WAGTAIL. SOME INSTANCES OF COLOUR=PROTECTION IN BIRDS' EGGS. By C. H. Topham. TO the casual observer the many and varied colours of birds' eggs are meaningless, and do not suggest anything beyond their curious beauty; yet probably every one of these varied and numerous shades serves a definite purpose in nature, principally as a means of conceal- ment from the many enemies to which a bird at this early stage of its existence is exposed, in the same way that it is protected later on in life, when all birds assume such colours, where necessary, as may best conceal them from their still greater army of foes; , as a general rule, all our feathered friends that spend the winter with us wear dull, dusky, or neutral liveries, so that they escape ready discovery while among the bare branches of our deciduous trees, which harmonise perfectly with their plumage. If this were not the case, hawks and other birds of . prey, would work sad havoc among our gentler winter residents. The reason that the under- surface of the bodies of such birds is lighter in colour than their backs is very apparent, for little clanger threatens them from beneath, and the branches themselves offer a natural protection from this quarter. The principal constitutent of which an egg-shell is composed is carbonate of lime (limestone), which in a pure state is a whitish substance: thus the interior of the shell of all eggs is white, or only slightly tinted. It is probable that the original colour of all eggs was white (a statement which is confirmed by the fact that all birds which lay their eggs in holes or build covered-in nests, , those that have retained this habit for some considerable time, lay white or pale eggs). Of the class of birds which build and deposit their eggs in holes may be mentioned the Owls, Woodpeckers, Tree-Creepers, Wryneck, Kingfisher, Sandmartin, and Puffin, as well as several other sea-birds; an
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Keywords: ., bookcentury1900, bookdecade1900, bookpublisherlondo, bookyear1902
