Birds ‘see’ magnetism?

How precisely do birds navigate over long distances without getting lost? In a Biophysical Journal article, we suggest that certain migratory birds might literally ‘see’ Earth’s magnetic field superimposed on their normal vision, reminiscent of a fighter pilot’s heads up display.

Our proposal builds on the established Radical Pair model of the avian compass, replacing the hypothetical chemical signal transduction stage, for which no evidence exists, with a physical mechanism, by which an electrical dipole field directly influence the visual process in the bird’s eye.

Apart from simplifying the story, our model provides an explanation as to why the evolution of an extraordinarily long compass coherence time would have been favoured by natural selection. This provides at least a partial answer to this puzzling questions which we raised with a previous Physical Review Letter on the same topic.

This work involved QuNaT members Erik Gauger, Simon Benjamin and Brendon Lovett. It is also available on the arxiv (http://arxiv.org/abs/1003.2628).