General Info/Characteristics Class Aves: 8,600 species Developed from a Theropod Dinosaur Endothermic: maintain constant body temperature (homeostasis and live in different environments.) Clawed toes and scales on feet only. Hollow bones to aid in easy flight. How do birds fly?
Wings/Feathers Feathers are modified scales, aiding in flight and providing protection and insulation. Preening: birds run bill through feathers to keep them in good condition. Molting: birds shed old feathers (in pairs to maintain balance), replacing them with new ones. Wings are front limbs, attached to sternum. Added info: flight muscles are attached to wings at sternum.
System Info Circulatory: Four-chambered heart (efficiency for increasing energy use) Respiratory: Lungs working during inhalation and exhalation. Reproduction: a.Lay shelled, amniotic eggs (reptiles) b.Internal fertilization c.Incubation (warmth) Digestive: a.Beaks to grasp/crush food b.Large quantities of food for energy (flight)
Diversity of Birds Similar appearance Behavior is main difference a.Penguins do not fly and have lots of fat b.Owls large eyes and are deft (skillful) flyers