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Home Adaptations Internal Organs
Tufted Titmouse

Tufted Titmouse
(Courtesy NEBRASKAland Magazine/NGPC)

Birds don't look much like humans on the outside. As you might expect, their insides are also different, even though their internal organs carry out the same basic functions human organs carry out.

It makes sense. Birds and humans have some things in common, but in general they don't move around the same way, eat the same things, or live in the same types of shelters.

Specialized internal organs are adaptations that meet a bird's specific needs and make bird life better, giving the bird the highly efficient respiratory system it needs for flight, the digestive system it needs to feed on the go, and the elimination system it needs to keep its body temperature regulated and get its wastes out of its system quickly.

Here's a quick comparison of bird body basics and human body basics.


What You Have

What Birds Have


  • Lungs
  • Air flow regulated by diaphragm movement
  • Lungs
  • Air sacs
  • Air flow regulated by sternum and rib movement


  • Four-chambered
  • Four-chambered


  • Teeth for chewing food
  • Stomach that digests chewed food
  • Beak for tearing or swallowing food whole
  • Gizzard that grinds up swallowed food


  • Sweat that evaporates to cool the body
  • Kidneys
  • Urine and feces excreted separately
  • Water loss through mouth and nose to avoid overheating
  • Kidneys
  • Uric acid that mixes with feces before being excreted


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