What Traits Do Birds Have?

Wings

• The front limbs of all birds have adapted as wings, although some birds are flightless. Birds commonly fly by flapping their wings, but once they gain enough power, wings may be held still and outstretched so the bird can glide. A bird's strongest muscles are those used for flight. Wings form a slight arc, which creates lift by allowing air to flow quicker and easier over the top of the wing than underneath it, where greater pressure builds.

Feathers

• Birds are covered in feathers, which perform a number of important tasks. In flight, feathers provide a bird with large, flat surfaces and an aerodynamic shape. Tail feathers can be used for balancing, steering and braking. Feathers are also used to insulate a bird's body by trapping warm air beneath them. This helps birds, which are all warm blooded, to maintain their body temperature. Colored feathers can also attract mates and provide camouflage. Birds maintain the quality of their feathers by preening. They also lose old feathers through molting and replace them with new ones.

Beaks

• Birds have tough beaks that protrude from their jaws and do not have teeth. The characteristics of an individual beak varies depending on species. Different species of birds have beak adaptations that help them consume their specific diets. For example, carnivorous birds have sharp, hooked beaks that help them to rip flesh, while birds that eat nuts and seeds have very tough beaks.

Skeleton

• A bird's skeleton is made of hollow bones that aid flight by helping to keep the bird lightweight. Although these bones are thin and light, they are surprisingly resistant. The majority of birds have a keel, which is an extended part of a breastbone. The muscles used for flight are attached to the keel and extend outward from it. A type of wrist on a bird's wing allows it to fold while the flapping motion of the wing is controlled from the shoulder.

Biological Systems

• Flight requires birds to have high metabolic rates that require a great deal of oxygen. Because of this, birds have large hearts that pump blood around the body very quickly. They also have a efficient respiratory systems that have large surface areas due to the presence of air sacs on the lungs that extend into bones and the abdomen. Another biological feature of birds is the absence of a bladder, which helps keep them light. Instead, uric acid crystals pass along with feces as a combined waste product.