The world of birds
          
        
        
          The smallest bird in the world is the bee hummingbird.
        
        
          
            135
          
        
        
          
            Flight
          
        
        
          A bird can fly because it has wings and
        
        
          a very light skeleton – many of the bones
        
        
          are hollow. Birds have short and
        
        
          compact bodies that make
        
        
          them neat fliers too.
        
        
          
            Travelling birds
          
        
        
          About one-third of
        
        
          birds spend summer
        
        
          in one place then
        
        
          when the winter sets in
        
        
          they fly thousands of
        
        
          miles to a warmer spot.
        
        
          Often they go to exactly the
        
        
          same places year after year.
        
        
          
            Communication
          
        
        
          All birds have good hearing
        
        
          so they can respond to songs
        
        
          from other members of their
        
        
          family. Birds are well known
        
        
          for their tunes, and some,
        
        
          like this parrot,
        
        
          even speak.
        
        
          
            Feet
          
        
        
          The shape of birds’
        
        
          feet vary depending
        
        
          on where they live.
        
        
          
            Bills
          
        
        
          The shape and size of a
        
        
          bird’s bill, or beak, can
        
        
          show what they eat.
        
        
          There are two methods
        
        
          of flying; flapping, like
        
        
          this red-tailed minla,
        
        
          and gliding.
        
        
          
            Perching foot:
          
        
        
          songbirds
        
        
          have three toes in front and
        
        
          one behind for perching.
        
        
          
            Eagle foot:
          
        
        
          birds of prey
        
        
          have sharp talons to kill
        
        
          and grip animals.
        
        
          
            Webbed foot:
          
        
        
          waterfowl
        
        
          have webbed feet to help
        
        
          them to paddle on water.
        
        
          
            Ostrich foot:
          
        
        
          two thick
        
        
          toes help this flightless
        
        
          bird to run very fast.
        
        
          
            Woodpecker:
          
        
        
          long
        
        
          and hard to chisel into
        
        
          wood and pick out insects.
        
        
          
            Duck:
          
        
        
          wide and flat to
        
        
          tear plants and filter
        
        
          food underwater.
        
        
          
            Chaffinch:
          
        
        
          short and
        
        
          cone-shaped, ideal for
        
        
          cracking seeds.
        
        
          
            Heron:
          
        
        
          long, ideal to stab
        
        
          fish underwater.
        
        
          
            Red-tailed
          
        
        
          
            minla
          
        
        
          By flapping
        
        
          its wings up
        
        
          and down, the
        
        
          bird remains
        
        
          in the air.