High resolution anatomical mapping confirms the absence of a magnetic sense system in the rostral upper beak of pigeons.
Treiber CD, Salzer M, Breuss M, Ushakova L, Lauwers M, Edelman N, Keays DA. High resolution anatomical mapping confirms the absence of a magnetic sense system in the rostral upper beak of pigeons. Commun Integr Biol. 2013 Jul 01; 6(4):e24859.