1) structural features and functions associated with flight: hollow bones, the transformation of the forelimbs into wings, the rapid digestion of food, etc.
2) features that provide a high level of metabolism and warm-bloodedness: 4-chamber heart, a special structure of the respiratory system, the consumption of a large amount of food, etc.
3) the development of the central nervous system, complex behavior (flights, care for offspring, etc.).
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.