impactology, Can Blind Birds Navigate?
https://www.youtube.com/watch?v=7yBMUrlpe5s
Apart from sight birds use
- Position of sun
- Cryptochrome : A protein in their eyes sensitive to blue light giving overlay of dark patches whose duration of staying active varies according to strength of earth's magnetic field
- Tiny magnetites on their beaks
- Olfactory map
So Soaring Birds like Wandering Albatrosses and Andean Condor catch thermals to fly for long time without flapping while doing all of the above as well!