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(Photo by Diana via Pexels)<\/p>\n
By Talker<\/p>\n
By Stephen Beech<\/p>\n
Pigeons find their way home by using magnetic sensors in their livers<\/a>, suggests new research.<\/p>\n Immune cells packed with iron act as an “internal compass” \u2014 helping the birds detect the Earth’s magnetic field, say German scientists.<\/p>\n How pigeons fly hundreds of miles and still find their way home has long fascinated people.<\/p>\n Now, scientists believe a surprising answer may be hidden, not in the birds’ brains or eyes, but in their liver.<\/p>\n The new study, published in the journal Science<\/a>, suggests that special cells in the liver of pigeons can sense the Earth’s magnetic field, giving them an internal compass.<\/p>\n The special cells \u2014 known as “macrophages” \u2014 are immune cells that break down old red blood cells.<\/p>\n As part of the process, they accumulate iron, giving them quantum properties that may allow them to respond to magnetic fields.<\/p>\n Electron microscopy image of pigeon liver tissue, with full colorization of cells. (Lisowski et al via SWNS)<\/p>\n By Talker<\/p>\n But, without the cells intact, the study shows pigeons could not navigate home.<\/p>\n Study co-senior author Christian Kurts, director at the Institute of Molecular Medicine and Experimental Immunology at the University Hospital Bonn<\/a>, said: “We didn’t expect immune cells to act like sensors for magnetic fields at all.<\/p>\n “Our results reveal a previously unknown mechanism for magnetic perception in animals.”<\/p>\n Co-senior author Martin Wikelski, director at the Max Planck Institute of Animal Behavior<\/a>, said: “What looks like a ‘gut feeling’ in bird navigation may actually have a physical basis.”<\/p>\n For decades, scientists have known that migratory birds and homing pigeons rely in part on the Earth’s magnetic field to navigate.<\/p>\n But exactly how they detect it has remained one of biology’s greatest unsolved mysteries.<\/p>\n Competing theories have suggested that birds might “see” magnetic fields through light-sensitive molecules in the eye, or detect them using tiny magnetic particles in the beak.<\/p>\n Homing pigeon being released by scientist at Max Planck Institute of Animal Behavior in Germany. (Christian Ziegler\/ Max Planck via SWNS)<\/p>\n By Talker<\/p>\n But none had come up with convincing experimental support.<\/p>\n The new study proposes a different mechanism for magnetic sensing, supported by a combination of lab tests and behavioral experiments.<\/p>\n The team included immunologists from the University of Bonn<\/a> and the University Hospital Bonn; physicists from the University of Duisburg-Essen<\/a>; and ornithologists at the Max Planck Institute of Animal Behavior (MPI-AB).<\/p>\n To identify where magnetic cells are found in pigeons, the research team used techniques known as “vibrating sample magnetometry” and “magnetic cell separation” to screen organs thought to be involved in magnetic sensing, including the eyes, beak, and brain.<\/p>\n They also examined the liver and spleen.<\/p>\n<\/p>\n
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