Why do only some birds fly?? 

 

Asked by deepali.09deshmukh | 17th Sep, 2019, 07:00: PM

Expert Answer:

  • Birds use their strong breast muscles to flap their wings and give them the thrust to move through the air and fly. 
  • Some birds are unable to fly if their wingspan or breast muscles are not great enough to create the lift needed to fly.
  • Birds such as ostriches, emus, and kiwis cannot fly as their flat breastbones lack the keel that anchors the strong pectoral muscles required for flight.
  • These birds are called flightless birds which have lost the ability to fly in the course of evolution.  

Answered by Sheetal Kolte | 18th Sep, 2019, 09:58: AM