BIRDS

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BIRDS
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Bird Facts

• Class Aves
• 10,000 species
• Heart has 4 chambers
• 1000 beats/minute
• Small, hollow bones
• Few fossils b/c bones decompose easily

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4 Main Characteristics of all Birds

• Warm-blooded (104)
• Feathers and scales
• Hard-shelled eggs
• Front legs are wings

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You eat like a BIRD!

• Eat LARGE amounts of food to supply the required
  energy to fly
• Usually eat insects, nuts, seeds, or meat some
  (geese) eat grass, leaves, other plants
• Very fast digestion digest in 1 hour what
  humans digest in 1 day
• FOOD ?mouth ?crop ?gizzard ?intestine ?anus

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EGGS

• Reproduce sexually
• Internal fertilization
• Hard-shelled eggs
• Shell made of calcium carbonate (seashells,
  marble)
• Amniotic eggs
• Usually lay 2 to 8 eggs at a time (clutch)
• Birds must incubate their eggs sit on them to
  keep them warm until they hatch ? brooding

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Precocial Altricial

• Precocial chicks that are active soon after
  birth
• (Chickens ducks)
• Covered w/ downy feathers
• Can walk, swim, feed themselves
• Altricial chicks that are helpless and weak
  after hatching
• (Hawks songbirds)
• No feathers
• Eyes closed
• Can NOT walk or fly
• Parents must feed them and keep them warm

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Flight - How?

• Light, rigid skeleton (hollow bones with cross
  supports)
• Wings (curved)
• Keen senses (vision and hearing)
• A lot of energy
• Powerful chest muscles anchored to the keel
• Muscles get lots of oxygen-rich blood from a
  fast-beating heart
• Have air sacs that store extra air for lungs
• Feathers
• All these things help a bird achieve lift an
  upward force on a birds wings

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Feathers

• Contour feathers
• Used to fly
• Help steer and balance
• Give coloring and smooth sleek shape
• Stiff main shaft
• Down feathers
• Fluffy
• Insulating layer next to birds skin
• For warmth

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More about feathers

• Preening birds use an oil gland and their beak
  to rub oil over their feathers this makes the
  feathers water-repellant
• Molting shed a few feathers at a time
  (once/year)

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Senses

• Vision
• Important for take off and landing
• Important for hunting
• Hearing
• Important for locating prey
• Important for avoiding danger

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THE END!!!