1. CHAPTER 12 SECTION 1 Birds

2. Characteristics of Birds Endotherm Vertebrate that has feathers Four-chambered heart Lays eggs Most can fly Scales on feet and legs

3. Adaptations for Flight Bones are nearly hollow Bones of a bird’s forelimbs form wings  Flying birds have large chest muscles to move wings Flight feathers  Extend from contour feathers, help it balance and steer

4. 2 Types of Feathers Contour  Large feathers that give shape to a bird’s body  Consists of a central shaft and small hairlike projections called BARBS  Hooks hold barbs together  Sometimes “unzip” during flight  Birds “zip” barbs back together during preening  Long feathers that extend from contour feathers are called flight feathers Down  Specialized to trap heat, soft  Near bird’s skin

5. Obtaining Oxygen/Circulatory System System of air sacs, connects to lungs  Enables birds to obtain more oxygen Heart with 4 chambers  2 atria  2 ventricle  Right side of heart = oxygen-poor blood to lungs  Left side of heart = oxygen-rich blood to body Four chambered heart does not mix blood, blood circulates to body’s cells has plenty of oxygen

6. Respiration

7. Obtaining Food Use their bills  Help birds feed quickly and efficiently  Hawk– pointy, curved bill  Duck– kitchen strainer Crop  Internal storage tank, used for storing food inside the body after swallowing  Connected to stomach Gizzard  Squeeze and grinds partially digested food  Contains small stones

8. Keeping Conditions Stable Since they are endotherms they need a lot of energy to keep body temperatures stable and for flight Eat about ¼ of body weight per day Use feathers to keep warm

9. Reproduction and Caring For Young Internal fertilization Lay eggs Shells are harder than reptiles Female lays eggs in a nest Either parent can sit on the eggs to incubate them  Eggs must stay warm in order to develop Stay with their young until they are able to fly

10. Birds in the Environment 10,00 species Adapted for living in diverse environments  Legs  Claws  Bills Perching Birds– goldfinches and mockingbirds Woodpeckers– tools for chipping wood Hummingbirds– pollinators Ostriches– cannot fly but can move quickly Predator birds– eat pest animals