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BIRD CHARACTERISTICS. By Samara. Characteristics of Birds. There are about 8600 species of modern birds Birds are the most common vertebrates besides humans and mammals you see in your daily life
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BIRD CHARACTERISTICS By Samara
Characteristics of Birds • There are about 8600 species of modern birds • Birds are the most common vertebrates besides humans and mammals you see in your daily life • Sometimes referred to as feathered dinosaurs: fossil evidence indicates birds evolved from the two legged dinosaurs called tripods
Feathers • Birds are the only living organisms with feathers Feathers- lightweight, modified scale that provides insulation and enables flight Preening- process that keeps the feathers in good condition for flight • Birds use their beak to rub oil from a gland near the tail onto the feathers as a way to water proof the feathers(important in water birds)
Take Flight • The adaptation that enables flight in birds is the modification of the front limbs into wings • Powerful flight muscles are attached to a large breastbone called the sternum and to the upper bone of each wing Sternum- supports the enormous thrust and power produced by muscles as they move to generate the lift needed for flight
Cont. Flight requires high levels of energy • Birds have a rapidly beating (4) chambered heart • The respiratory system supplies oxygenated air to the lungs when it inhales as well as when in exhales • Respiratory system consist of anterior and posterior air sacs • During inhalation oxygenated air passes through the trachea into the lungs where the gas exchange takes place Most air however moves through the lungs and passes directly in to the posterior air sacs • During exhalation deoxygenated air from the lungs, oxygenated air returns to the lungs from the posterior air sacs FACT: A chickadee’s heart beats 100 beats per minuet compared to a humans who only beats 70
Endotherms • Birds are able to maintain the high energy levels needed flight because they are endotherms Endotherms- is an animal that maintains a constant body temperature. -Birds have a variety of ways to maintain body temperature • Feathers reduce heat loss in cold temperatures • Birds also pant to increase respiratory loss • Major advantage of being endothermic for birds is that they con live in all environments -Disadvantage to birds and other endotherms is that they must eat large amounts of food to sustain these higher levels of energy
Reproduction • Reproduce through internal fertilization • Lay amniotic eggs inside a nest • Bird eggs are encased in a hard shell, unlike the leathery shell of a reptile • Birds are very protective of eggs and they never leave the eggs to hatch on there own • In stead they incubate Incubation- process of keeping eggs laid outside of the body warm; also provides periodic turning if the eggs to ensure a proper development
Cont. • In some species of birds, both parents take turns in incubating the eggs • Bird eggs are distinctive and can sometimes be determined by the size, shape, and color
Diversity • Birds are all very much alike in their basic form and structure • Very easy to recognize