. Bird lore. Birds; Birds; Ornithology. 262 Bird - Lore snow-white, having no pigment whatsoever, the eyes being red owing to the blood showing through the iris. They are apparently much more frequent with domestic animals than in the wild state, as in the familiar white mice, rats, and rabbits, but they are likely to occur at any time with any species. The brown pigment seems the most likely to disappear, pure albinos of birds having red or yellow in their plumage being extremely rare. The Meadowlark in the accompanying photograph, for example, shows a well-defined tinge of yellow on the unde
. Bird lore. Birds; Birds; Ornithology. 262 Bird - Lore snow-white, having no pigment whatsoever, the eyes being red owing to the blood showing through the iris. They are apparently much more frequent with domestic animals than in the wild state, as in the familiar white mice, rats, and rabbits, but they are likely to occur at any time with any species. The brown pigment seems the most likely to disappear, pure albinos of birds having red or yellow in their plumage being extremely rare. The Meadowlark in the accompanying photograph, for example, shows a well-defined tinge of yellow on the underparts and before the eye. Partial albinos are much more frequent with all species, and mottled Robins and Sparrows or birds with white feathers in unusual places are not at all infrequent. Usually this partial albinism is symmetrical on each side of the bird but it is not always so. The exact cause of albinism is not known though it is thought to be a form of physical weakness due to inbreeding or to some other cause. More unusual than albinism is what is called dichromatism (from the Greek di+khromatikos, meaning two-colored) or the occurrence in a species of two color phases irrespective of age, sex, or season. The familiar Screech Owl affords us a good example where extremes of red and gray individuals occur as well as intermediates. These may be, and often are, individuals from the same nest, and they may be all males or all females. It is apparently due to an excess of red or brown pigment and may represent but a step toward melanism. Dichromatism likewise occurs with certain other owls, and with certain Hawks, as well as with some species of Herons. The case of the rare Cory's Least. A DISABLED CORY'S LEAST BITTERN This species is probably only a color-phase of the common Least Bittern, but such 'dichromatism', as it is called, is rare except with certain Herons, Hawks, and Owls. Please note that these images are extracted from scanned page images that may have been digi
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbirds, booksubjectorn
