BIRDS

BIRDS

1. what are birds ?

   • birds are vertebrate terrestialanimals and most of them can fly

2. nutrition and reproduction

   • nutrition
     • they have heterotrophic nutrition
       • carnivours
       • hervibours
   • reproduction
     • sexual reproduction they are oviparous

3. main types of birds

   • carinate
     • it has a keel
     • air sac
     • it wings are well developed
   • ratitate
     • it has no keel
     • it has strong legs for running
     • it wings are atrphied

4. charasteristics

   • all birds have wing but some ones can fly
   • beak (pico) all have it
   • all bids lay eggs they are oviparous
   • their mandibles have no teeth
   • coverd by feathers some are for flying and the other to preserve body heat
   • their breath with lungs that air linked to thr air sac were thy store oxygen
   • they are endothermic that means that they mantein heat
   • have aerodinamic body
   • they have a lightweight skelleton and their bones are hollow ( huecos )