[tzs]

Are you referring to animals (including, under the right conditions, humans) seeing the polarization of light?

That allows them to figure out the position of the Sun when it is not visible due to clouds, which is indeed useful for navigating.

But what this article is about is seeing the Earth's magnetic field.

At least some migratory birds are able to detect both their longitude and latitude [1] [2], which requires more than just knowing where the Sun is.

Humans have been able to figure out latitude for a very long time...at least as far back as the ancient Greeks, and probably much farther back.

Longitude, on the other hand, eluded us until we were able to make reasonably accurate clocks. For sea navigation, that wasn't until the 18th century, long after we had compasses and knew about polarized light.

[1] http://www.cell.com/current-biology/abstract/S0960-9822(17)3...

[2] https://www.uni-oldenburg.de/en/news-single/art/how-migrator...