meaning of exceprt from big book rc

[subbukambala]

>> from 23rd test/section 1

common sense alone cannot explain how birds navigate the ocean: after a flock traveling east is blown far south by a storm, it will assume the proper northeasterly course to compensate


can anyone please explain meaning of this.

[Laborer]

Common sense would say that birds fly in a certain direction because they want to, and that it's a fairly linear journey from point A to point B.

However, that cannot explain how birds end up taking a different path to reach that destination.

If a flock of birds is blown south by a storm, and they want to go east, they will fly NORTH EAST to compensate for falling off their original path. They're still headed towards the same destination, but they need to adjust it a little bit.

Hence, it's not really a linear A to B path. It's usually adjusted a little bit. That's why the behavior of birds isn't always explained by common sense.