Compléter BirdsVersion en ligne You can review the important information about birds. par Chari P. 1 regulate endothermic temperature Birds are vertebrates . This means they can their own body . 2 fly flying Most birds are adapted to . Some can't , like ostriches . 3 flight aerodynamic resistance less Birds have bodies , which have air . This helps with . 4 legs bodies scales feathers Birds' are covered in , except for the which are covered in . 5 beaks teeth Birds have and don't have . 6 hollow lighter flight They have some bones , which make them and facilitate . 7 limbs anterior wings Their are . 8 lungs sacs air weight muscles They breathe using their . These have to help reduce their and oxygenate the during flight . 9 gizzard chew Birds don't their food . They have a region in their digestive system called the that breaks food up . 10 hearing eyesight Birds have very well - developed and . 11 communicate sing emit Sme birds sounds and " " to with other members of their species . 12 sexually internal oviparous Birds reproduce through fertilisation . All birds are .