Data was collected concerning Galapagos bird beak size over time. There are several species finches, and they are also known as
Darwin's Finches. These finches share the same habits and characteristics except for one; they all have different shaped and sized beaks. The differences in their beaks might be the most important aspect of their survival. Around 1977, there was a huge drop in finches with small beaks while there was a great increase in large-beaked birds. How can you explain this?
Finches adapt to the new conditions such as drought by changing the size, shape and depth of their beaks. Beak morphology varies according to drought conditions. Since after the drought, vegetation dries out and the hard, big, tough seeds remain, only the finches with deep beaks will survive. Finches adapt via their beaks to different foods sources and different local conditions.
Darwin studied the finches which differed mainly in their beak shape and size. These finches evolved with various beak sizes based on the availability of food. Long beaks would be helpful to pick the seed from the cactus fruits whereas short beaks would be helpful to feed on seeds at the ground level. The unavailability of food i.e seeds at the ground level would have caused such changes. Its survival of the fittest while adapting to their new or changed environment.
