In this question, there are no options given to choose from. So i would answer this question based on my knowledge. The most likely cause of the observed variation is adaptation and evolution. The birds of that island adapted to the food source and then they evolved as per the requirement of the place and food source.
Жила была царевна но туда ей бросил лёд
Answer:
Eggs are among the best sources of protein in the diet. In fact, the biological value (a measure of protein quality) is often evaluated by comparing it to eggs, which are given the perfect score of 100 ( 16 ).
Explanation: