What is an instinct that geese use when they fly South for the winter?

Geese use a strong migratory instinct that is largely driven by changes in daylight and temperature, which signal the need to move south for warmer climates and more abundant food sources. This instinct is often guided by genetic programming, allowing them to navigate accurately using the Earth's magnetic field, the position of the sun, and landmarks. Additionally, social learning plays a role, as younger geese learn migration routes by following experienced adults.