. The bird, its form and function . e darkabove and white or whitish beneath. The significanceof this pattern of coloration has been beautifully demon-strated by an American artist, Mr. Al)l)ott Thayer. Hisexperiment, which is as follows, may he repeated by anyone: Take two wooden deco\ ducks, and place themagainst a sand-bank. Colour one the exact tint of thesand, or even coat it with that substance. Repeat thiswith, the upper parts of the second decoy, maknig itsback darker than the surroundmg sand, l)ut grade theunder part of this one to pure white below. At a littledistance away, decoy num
. The bird, its form and function . e darkabove and white or whitish beneath. The significanceof this pattern of coloration has been beautifully demon-strated by an American artist, Mr. Al)l)ott Thayer. Hisexperiment, which is as follows, may he repeated by anyone: Take two wooden deco\ ducks, and place themagainst a sand-bank. Colour one the exact tint of thesand, or even coat it with that substance. Repeat thiswith, the upper parts of the second decoy, maknig itsback darker than the surroundmg sand, l)ut grade theunder part of this one to pure white below. At a littledistance away, decoy number one will still be distinctlyseen; while number two will al)solutely disapj)ear, mc^-g-ing perfectly into its background. The reason for this is ;oo The Bird that the conspicuous white of the under surface of thesecond bird is, when normally lighted up by the sun,neutralized by the shadow^ of the bird, and the darkerupper parts are softened and toned dow^n by the strongdirect light; while if the entire bird be unshaded, although. Fig. 238.—Sooty Tern on her nest. coloured like the environment, the dark shadow beneathwill reveal it clearl3\ \Miether or not birds really appreciate the value ofthe ]^rotective colour of their plumage, it is certain thata quail or ptarmigan will remain crouching on a brownbit of turf, until all hope of evading danger is gone; whilebirds which are very evidently not protectively colouredare invariably more wary and difficult of approach. AMien
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Keywords: ., bookauthorbeebewil, bookcentury1900, bookdecade1900, bookyear1906
