Bird migration: how do birds navigate themselves in flight?

Migrating birds are sensitive to the Earth's magnetic field, that is aiding their navigation on long journeys towards their breeding and overwintering grounds.
Magnetoreception is one of the many mechanisms that migratory birds use to navigate. They often combine this ability with other cues, such as stars, sun, gravitational field and visual cues. These incredible abilities of birds are being affected by urban/agricultural development. City lights confuse birds during nighttime. On top of this, the proliferation of large-scale farming and climate change are shifting the migratory patterns of certain species and endangering them on their journeys. According to the International Union for Conservation of Nature, one third of all nesting birds in mainland France are now at risk of extinction. The Col de Golèse, visible from this meadow, is an important migratory route.