. On the natural history and classification of birds . ions on theimpossibility, or the inexpediency, of giving definitenames to the minor variations. (117.) Walking feet, among the perchers, do notimply a similarity of structure to those of the Rasores,which never have the hind toe upon a level with theothers; but rather that feet, so formed, are adapted bothfor walking and perching. Thus every one knows thatthe crows and starlings walk more frequently thanthey hop ; and it is therefore essential to birds of suchhabits, whose chief food is upon the ground, that theirfeet should have a particu
. On the natural history and classification of birds . ions on theimpossibility, or the inexpediency, of giving definitenames to the minor variations. (117.) Walking feet, among the perchers, do notimply a similarity of structure to those of the Rasores,which never have the hind toe upon a level with theothers; but rather that feet, so formed, are adapted bothfor walking and perching. Thus every one knows thatthe crows and starlings walk more frequently thanthey hop ; and it is therefore essential to birds of suchhabits, whose chief food is upon the ground, that theirfeet should have a particular conformation. Hence wefind that nearly all terrestrial birds, strictly so called,have the lateral toes perfectly equal, that is, of thesame length. The crow (fig. 67. a), rook, starling,and blackbird, besides many others, familiar inhabit-ants of our fields and lanes, sufficiently illustrate thisfact. In proportion as the habits of a bird are arborealrather than terrestrial, so is this equality of the lateral K 130 ON THE CLASSIFICATION OF toes diminished, and the inner one becomes propor-tionally shortened. This we see in the jays (6), which seldom alight upon theground^ even in situa-tions like this*; wheretheir wild and discor-dant cries echo throughthe coppices, and evincethat such wooded re-treats are their properhaunts. Another cha-racter, indicative ofwalking habits, will befound in the claws;those of the crow ( c) are always lesscompressed and curvedthan in the jay (a), andother birds which live in trees. This structure is carriedto its extreme development in the larks (d), and the neighbouring genus An-thus, where the clawsare unusually straightand slender, while theopposite extreme is seenin the genus Buphaga(b). We must, how-ever, observe that thereare several excep-tions to this rule; for not only the typical shrikes(Lanius) which never, or very rarely, alight upon theground, have the lateral toes equal, but this equality isseen in several other g
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Keywords: ., bookcentury1800, bookidonnaturalh, booksubjectbirds, bookyear1836
