Foxy Magnetism

Hast ‘ou seen the rose in the steel dust
(or swansdown ever?)
so light is the urging, so ordered the dark petals of iron
we who have passed over Lethe. �Ezra Pound, Pisan Cantos 74. 839�42

The fox hasn’t been over the Lethe, but it may see the “rose in the steel dust”�the parabolic loops of magnetic fields�if a group of Czech and German wildlife biologists is right. They theorize that foxes use magnetized retinal tissue to “see” the Earth’s magnetic fields. Lining up the sounds made by hidden prey with a shadowed “bullseye” made by magnetic fields in its field of vision, the fox could judge its predatory leap with great precision. The team’s primary evidence is circumstantial: in the Royal Society’s journal Biology Letters, they report that when striking at hidden prey, foxes under observation were much more frequently successful when jumping to the north. Other investigators have limned the ways in which animals may use magnetic sensing as an augmented-reality system not only to find direction, but to build a map of their immediate surroundings. �via PopSci