Birds and beaks
The different beaks of birds are adaptations to allow them to use different foods. This reduces competition and helps survival.

• Seed-eaters require short vice-like beaks for crushing hard seeds, e.g. budgerigar.
  
  
• Predatory birds require long, sharp, tearing beaks for grasping animals and ripping through flesh, e.g. eagle.
  
  
• Nectar feeders have a long thin beak with a brushed tongue for nectar gathering, e.g. honeyeater.
  
  
• Fish gatherers may have a large pouched beak to store fish, e.g. pelican.
  
  
• Worm and shellfish eaters may have a long spoon-shaped bill for burrowing in the sand, e.g. spoonbill.

Birds and feet
Birds' feet are also adapted to their environmental conditions.

• Swamp or estuarine birds have long wading legs with wide feet to prevent sinking in the mud, e.g. heron or stilt.
  
  
• Branch-dwelling birds have strong small gripping feet, e.g. parrot.
  
  
• Predatory birds need large talons for gripping and carrying small prey, e.g. falcon.
  
  
• Water birds (e.g. swans or ducks) have feet which are adapted with webbing which acts like a paddle for swimming.
  

Charles Darwin studied finches in the Galapagos Islands during his exploration on the ship, "The Beagle"(1835).

He found that several species of finches co-existed on the same island because each had their own niche, eating different diets and living in different areas (e.g. ground-dwellers, tree-dwellers and so on). Each showed different adaptations specialising them for their specific roles. This prompted his Theory of Evolution Through Natural Selection (see Species and Evolution).