ANATOMY OF BIRDS
Bird Wings
Bird Bone Structure
Bird Feathers
Bird Pectoral Muscles
Bird Sternums
Bird Leg Bones
Bird Perching Bones
Bird Pelvic Bones
Bird Vertibrae
Bird Scull Structure
Woodpecker sculls
Bird Beaks
ANATOMY OF BIRDS
GEOGRAPHICAL DISTRIBUTION
MIGRATIONS OF BIRDS
CLASSIFICATION OF BIRDS
LIZARD-TAILED BIRD
AMERICAN TOOTHED-BIRDS
THE OSTRICHES
THE RHEAS
EMEUS AND CASSOWARIES
THE TINAMOUS
THE KIWIS
THE PENGUINS
LOONS AND GREBES
ALBATROSSES & PETRELS
STORK-LIKE BIRDS
GOOSE-LIKE BIRDS
FALCON-LIKE BIRDS
FOWL-LIKE BIRDS
CRANE-LIKE BIRDS
PLOVER-LIKE BIRDS
CUCKOO-LIKE BIRDS
THE ROLLER-LIKE BIRDS
SPARROW-LIKE BIRDS
Birds and Birding's Guide to:
Watching THE ANATOMY OF BIRDS
Bird Feathers
The wings of a bird comprise the same parts as the fore limb of a mammal or reptile, and save in the hand, we can readily recognize these various parts, the upper arm (humerus), forearm (radius and ulna), wrist, and hand.
The bones of the fore limb are modified for the support of the large feathers forming the wing, the hand being reduced to three fingers, while only two of these, those to which the primaries are fastened, are of much use.
The wrist of the adult bird, frequently called shoulder, consists of but two bones; the part corresponding to the palm of the hand comprises three metacarpals and two carpals solidly fused into one mass, though this can be seen only in a very young bird. Following this is a short finger on the front edge of the wing bearing the so-called bastard wing, one long central bone and one shorter more or less pointed.
The stages by which the clawed hand has been transformed to a wing may be gathered partly from fossils and partly from a study of the embryo, but it is not quite certain whether the first finger of a bird, that bearing the so-called spurious wing, corresponds to the first or second finger of man, with the probability in favor of its being the second. The wing bones are lengthened or shortened in a pretty direct ratio to the rapidity with which the wings are moved, being longest in such sailing birds as the Albatross and shortest in the Pigeons and Hummingbirds.
The shortening is greatest in the humerus; for while in the Albatross and Frigate-bird the upper arm and forearm are about equal, in the Pigeons the humerus is somewhat shorter, and in the Hummingbird very much shorter, than the succeeding bones. This relates to the fact that a bird's wing is a lever of the third order, with the shoulder joint representing the fulcrum, the muscle the power, the end of the wing the weight.
The shorter the wing, the easier it is to move it rapidly; the more rapidly it is moved, the stronger must it be. The wing of a Condor or Albatross would break, were sufficient power applied to move it as fast as that of the Pigeon. The rapidity of the wing stroke is also indicated by the development of the processes about the inner end of the humerus for the attachment of wing muscles, these reaching by far their greatest development in Hummingbirds.
Footer
Footer