Magnetic Cues

What is polarized light and how is it formed?

Sunlight scattered by atmospheric molecules becomes polarized, forming a predictable pattern related to the sun’s position.

How can animals use polarized light for orientation?

Even when the sun is obscured, they detect the polarization pattern to determine direction.

What experiment showed this?

European Robins oriented correctly under a clear evening sky but lost orientation under depolarized light.

What is geomagnetic orientation?

The ability to use the Earth’s magnetic field for navigation, useful in both short- and long-distance travel.

What three magnetic field properties provide navigational information?

Polarity (north–south), inclination angle (angle relative to the surface), and field intensity (strongest at poles, weakest at equator).

What evidence shows animals use magnetic maps?

Spiny lobsters, sharks, and sea turtles all change swimming direction when exposed to artificial magnetic fields simulating different geographic locations.