Compléter BirdsVersion en ligne You can review the important information about birds. par Chari P. 1 endothermic regulate 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 resistance less aerodynamic Birds have bodies , which have air . This helps with . 4 bodies feathers scales legs Birds' are covered in , except for the which are covered in . 5 teeth beaks Birds have and don't have . 6 hollow flight lighter They have some bones , which make them and facilitate . 7 wings limbs anterior Their are . 8 air lungs weight sacs 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 eyesight hearing Birds have very well - developed and . 11 sing emit communicate Sme birds sounds and " " to with other members of their species . 12 oviparous sexually internal Birds reproduce through fertilisation . All birds are .