feet of birds


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feet of birds - Feet of birds
feet of birds - Hardly less diversified in form are the feet of birds. The skeleton of this part of the body is dealt with on another page; here we are concerned only with the external form of the feet and legs. Aquatic birds often have webbed feet, but not always. The Dipper, for example, is a bird which lives largely on and under the water, but its feet are not in the least like those of a Duck or Grebe. The webbed foot presents us with at least two varieties. In the Pelican tribe (fig. 1) the extreme of web-footedness is to be seen. Here all the toes (four) are connected by a webbing. In the Duck only three of the toes are webbed Another kind of webbed foot is termed palmate. In the Coots, for example, each toe is fringed with a broad membrane, but there is no connection between the fringes of successive toes. The toes of birds are apt to be differently disposed. In most birds (fig. 2) there are three toes which are turned forwards, and one, the great toe (hallux), which is turned backwards. But in the Trogons and others two toes are turned forwards and two backwards, thus producing a very efficient mechanism for holding on tightly to the bough of a tree, a mechanism which is shared by that, in some other respects, bird-like lizard, the chameleon. A foot pf this kind is technically called ' zygodactyle.' A singular modification of the foot is seen in the Kingfisher (fig. 3) where the two middle toes are enclosed in the same fold of skin; this is called syngenesious.'

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beak of birds

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