Pigeon Magneto?

Birds are famously good navigators. Some migrate thousands of miles, flying day and night, even when the stars are obscured. And for decades, scientists have known that one navigational skill they employ is an ability to detect variations in the earth’s magnetic field.

How this magnetic sense works, however, has been frustratingly difficult to figure out.

Now, two researchers at Baylor College of Medicine, Le-Qing Wu and David Dickman, have solved a central part of that puzzle, identifying cells in a pigeon’s brain that record detailed information on the earth’s magnetic field, a kind of biological compass.

https://www.nytimes.com/2012/04/27/science/study-sheds-light-on-how-pigeons-navigate-by-magnetic-field.html