In order to adapt to flight, birds needed strict anatomical and physiological adaptations, which, however, were not an obstacle to conquering different environments.
- •The feathers that cover their bodies are one of the best known features of birds. Feathers play an important role: they assist in flight and thermal insulation, and attract sexual partners.
- •They have two pairs of limbs, the front ones transformed into wings that allow flying and the hind ones adapted for walking, swimming, etc...
- •Their skeleton is delicate, strong, completely ossified. It is lighter than that of other invertebrates to facilitate flight.
- •Their mouth is shaped as a horny beak, adapted to the type of food they eat.
- •Their sense organs are perfectly adapted to their way of life. In general, sight and hearing are well developed, while the senses of smell, taste and touch are weak.