The humerus joins the radius and ulna (forearm) to form the elbow. The carpus and metacarpus form the "wrist" and "hand" of the bird, and the digits are fused together. The bones in the wing are extremely light so that the bird can fly more easily.
wing, in zoology, one of the paired structures by means of which certain animals propel themselves in the air. Vertebrate wings are modifications of the forelimbs. In birds the fingers are reduced and the forearm is lengthened.
Extant volant birds possess a highly specialized wrist joint, in which two proximal carpals articulate with a fused carpometacarpus.
Wrist. The bend of a bird's wing is its wrist—the first joint down from the wingtip—and how that wrist is held can distinguish different species.
In birds, the ulna and radius run parallel to each other without rotational movement and the ulna is larger than the radius. The carpalia and metacarpalia are joined and reduced to a few bones, such as the carpometacarpus, os carpis ulnare, and os carpi radiale.
A bird can bend its wrist to the point where the side of the hand where the little finger would be can lie closely alongside the forearm, so any fingertips would point back almost towards the elbow, but the wrist cannot bend in the opposite direction, nor even fully straighten.
The carpus and metacarpus form the "wrist" and "hand" of the bird, and the digits are fused together. The bones in the wing are extremely light so that the bird can fly more easily.
Birds are generally digitigrade animals (toe-walkers), which affects the structure of their leg skeleton. They use only their hindlimbs to walk (bipedalism). Their forelimbs evolved to become wings.
The main divisions are beak (or bill), head, back, throat, breast, wings, tail, and legs.
The wings of all birds share the same basic structure, consisting of flight feathers and wing coverts. Two types of feathers make up the flight feathers: primaries and secondaries. The primaries are the long feathers that form the wingtip. They attach to the avian skeleton's “hand” bones.
This four-bar mechanism follows from the specialized skeletal arrangement of a bird wing; the upper arm bone, the humerus, connects to two lower arm bones, the radius and ulna, which connect via the wrist to the carpometacarpus (figure 1d).
The common joints of the arms of chickens and humans are easily identifiable. The joint between the scapula and the humerus is the shoulder. The joint between the humerus and the radius/ulna is the elbow. The joint between the radius/ulna and the metacarpus is the wrist.
The leg consists of a long femur which attaches to the pelvis and then two bones of the lower leg. In the bird, these two bones: the tibia and fibula are fused together. In humans, they are separated. You are probably familiar with the tibia of the bird, that's the part you eat called the drumstick.
Digitigrades include birds (what many see as bird's knees are actually ankles), cats, dogs, and many other mammals, but not plantigrades (such as humans) or unguligrades (such as horses). Digitigrades generally move more quickly and quietly than other animals.
Crop (anatomy) - Wikipedia.
Avian character. In the furry fandom, an avian, also known as featheries, is a bird or bird-like character and/or person who generally identifies with said phenotype. As characters, this includes real birds, anthropomorphic birds, fantasy birds, and bird variants such as gryphons or cockatrices.
Wings help birds to fly. The strongest muscles are in the wings. These powerful wings help birds stay in the air. The wings of birds are uniquely adapted to their way of life.
The meaning varied, too–the word originated from the Anglo Saxon word “bredan,” meaning “to breed,” which gave “bird” its original meaning–a young bird (what we now call a chick). But by Chaucer's time the meaning was expanding to include all creatures with feathers.
Do birds' knees bend backwards? Not quite! The joint that you might consider to be their “knee” is actually their ankle joint. Their knee is higher up on the leg, and does bend in the same direction ours does.
Bird wings are a paired forelimb in birds. The wings give the birds the ability to fly, creating lift.
They do not stand on feet, but rather on their toes. What appears to be a backwards bent knee is actually their ankle or heel. Their knee does bend forward like a human's but you usually can't see it because it's covered by feathers. Most birds have four toes, with the first toe, or hallux, turned backwards.
The bend in the middle of the wing is actually the bird's wrist. The last joint of the wing is like our hand, but it has only one finger bone. This holds all the long primary feathers used for flying.
Evolution of Animal Wrist Bones
This limb is present in various animals, but it looks and operates differently for different species.
By employing both carpal bones simultaneously birds can lock the manus into place during flight. (3) Throughout the downstroke-upstroke transition, the articular ridge on the distal extremity of the ulna, in conjuction with the cuneiform, guides the manus from the plane of the wing toward the body.