What are the differences between day and nocturnal birds? It is the structural features of the body that are needed.

The plumage of diurnal birds of prey is elastic, rigid, there are almost no down feathers; at night, it is also elastic, but loose, the whole body is covered with feathers, the flight is silent.
Night birds have large eyes that can see well in the dark. But due to their large size, they do not rotate in orbits.
Hearing in nocturnal birds is very developed, the ears are formed by special folds of skin, which are so large that they close over the head, asymmetry is also present – the right ear is always larger than the left.