. The biology of birds. Birds. ADAPTATION TO HAUNTS 147 are less divergent from the ordinary Carinate type as regards both fore and hind hmbs. It is instructive to take a particular case in more detail— puffins, for instance. These attractive birds have short, narrow wings, but their flight is rapid and often zigzag, that is to say, under rapid control. When they launch themselves from a cliff, head bent down, wings raised up, webbed feet spread out behind, they often describe a fine whirring sweep before they alight with a splash in the sea. They paddle ^^N. Fig. 35.—Wing of Adelie Penguin, P
. The biology of birds. Birds. ADAPTATION TO HAUNTS 147 are less divergent from the ordinary Carinate type as regards both fore and hind hmbs. It is instructive to take a particular case in more detail— puffins, for instance. These attractive birds have short, narrow wings, but their flight is rapid and often zigzag, that is to say, under rapid control. When they launch themselves from a cliff, head bent down, wings raised up, webbed feet spread out behind, they often describe a fine whirring sweep before they alight with a splash in the sea. They paddle ^^N. Fig. 35.—Wing of Adelie Penguin, Pygoscelis adeliEe. A., from a specimen; b., after Pycraft. A novel structure, a flipper, has arisen from a typical wing, without very radical transformations, h., humerus ; R., radius; u., ulna; r., radiale ; 11., ulnare ; cmc, carpometacarpus; I., the thumb; , the first joint of the first finger; 11., the second joint; III., the second finger or third digit. deftly on the surface with their feet, but they swim under- neath the water with their wings. Indeed, it may almost be said that they fly under water. Unless helped by a head wind, they find it difficult to rise into the air, and they often splash along for some distance before they are clearly launched in flight. But they often fly several miles to the fishing ground many times in a day. Sometimes a large flock may be seen wheeling in unison, recalling the fact that auks (the family to which puffins belong) are related to the gregarious plovers. To this repertory of movements there has to be added the burrowing, for the nest is often at the end of a yard long tunnel. In the tunnelling, which is said. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Thomson, J. Arthur (John Arthur), 1861-1933. New York : Macmillan
Size: 3248px × 769px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectbirds, bookyear1923
