Migrating Canada Geese Align With the Earth’s Magnetic Field

Migrating geese use a fascinating navigational ability called magnetoreception to orient themselves during their long journeys. Magnetoreception refers to the ability of some animals to detect and use the Earth's magnetic field for navigation. Scientists believe that migrating geese have special “magnetoreceptive cells” in their eyes that allow them to sense the Earth's magnetic field. These cells contain a protein called cryptochrome, which is sensitive to magnetic fields. When light passes through the eye and interacts with the cryptochrome protein, it creates a chemical reaction that helps the geese perceive the magnetic field.

Driving Question

• How do migrating birds navigate?

Probing Questions

• What are ways humans interact with the Earth’s magnetic field?
• What are some ways scientists could test to see if geese really are using magnetism to navigate? What data could be collected?
• What other ways could Canada geese be navigating? Why do you think scientists have ruled out these navigation techniques?

Classroom Suggestions

Students could:

• Build a compass using a sewing needle, a magnet (to magnetically charge the needle), a bowl of water, and a piece of cork or foam. Have the students rub the needle on the magnet to charge it, then float the charged needle on top of a piece of cork or foam. The needle will align with the Earth’s magnetic field. Explain how the sensory cells in the eyes of geese work in a similar fashion, essentially acting as tiny compasses that result in geese being able to “see” Earth’s magnetic field.
• Use a compass in a classroom, then move near magnets and try using it again. Students should explore how magnets interfere with a compass, even when the compass and magnet are not in contact with one another. They could use this information to come up with ideas of how scientists could test to see if migratory birds really do use magnetoreception.

Relevant Related Resources

Explaining Bird’s ‘Sixth Sense’ | YouTube: This video explains how magnetoreception in birds is the most likely reason they are able to successfully navigate the Earth.
Magnet & Compasses | PhET Simulation: This simulation shows how compasses are used on Earth and how they align with the Earth’s magnetic field. The specialized cells in a migratory bird’s eyes would work similar to a compass.