Many nocturnal birds fly in complete darkness, avoiding all obstacles. What helps them in this?

Nocturnal birds that lead a predatory lifestyle are good at flying in the dark and hunting. For example, owls are a typical nocturnal predator. These birds have keen eyesight. The eyes are large, they look straight. The head can be rotated within a radius of 180 degrees, which gives a wide outlook. Also, in nocturnal birds, the organ of hearing and the vestibular apparatus are well developed. Thanks to this, the bird is well aware of the movement of its prey and even a slight rustle of any objects, it is easy to navigate in space in pitch darkness.