Answer:
Evolution or Adaptation
Step-by-step explanation:
Because of the available food in the environment, such as big or small, hard or soft seeds based on the weather and the plant's production, the birds have to adapt to be able to consume their new type of food available, if a bird with a small beak tried to eat a large hard seed, it wouldn't be able to, or if a bird with a big beak tried to eat a small seed, it probably wouldn't be enough