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Science

Pigeons May 'Hear' Magnetic Fields 55

Posted by Soulskill from the for-the-birds dept.
ananyo writes "Individual neurons in birds' brains can relay crucial information about Earth's magnetic field, possibly providing the animals with an 'internal GPS.' Pigeons' remarkable navigational feats have long been pegged to the birds' ability to sense magnetic fields, but pinning down how they do so has frustrated scientists for years. Work published in Science (abstract) shows that individual cells seem to encode information on a magnetic field's direction, intensity and polarity. The work also suggests that these signals come from a part of the inner ear called the lagena, further complicating matters for researchers in the field. The Science paper comes just days after a report in Nature (abstract) revealed that cells in pigeons' upper beaks, previously thought to be magnetoreceptors, are actually immune cells called macrophages."
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Pigeons May 'Hear' Magnetic Fields More

Pigeons May 'Hear' Magnetic Fields

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  • I wonder if this is the same case for sea turtles (Score:4, Interesting)

    by GoodNewsJimDotCom ( 2244874 ) on Friday April 27, 2012 @04:01PM (#39826385)
    People remark how the turtles can find a small location in the middle of the ocean years after they were born. As long as the Earth's magnetic poles don't radically shift, the turtles could mark a location in their mind when they're born. Then when they need to mate, the signals to their brain tell them where to go on that primal mark.

    This is just a random wandering thought. If someone is more informed, feel free to enlighten me.

    • turtles have been known to vote for obama. they are communists and muslims, and you need to cease with this idealized image of turtle innocence

    • Re: (Score:3)

      by mikael ( 484 )

      My dad's workplace did some research into the accoustics of ocean eater. Ocean water has temperature, pressure, salinity gradients plus different types of wildlife at different latitudes and longitudes. All of these are going to allow creatures to triangulate their location.

      It's like penguins that form huge colonies in the icy blizzard region. Navigating by visual landmarks is impossible in a blizzard, so they form a navigation system by constantly calling out.

      • Ocean water has temperature, pressure, salinity gradients

        No, the ocean does not have pressure gradients - pressure varies with depth and nothing else. Temperature gradients vary wildly with the seasons. Salinity gradients are very weak, and only occur where there are either a) massive inputs of fresh water, or b) massive amounts of evaporation.

        So no, none of these will really work to provide navigation cues.

    • As long as the Earth's magnetic poles don't radically shift, the turtles could mark a location in their mind when they're born.

      You can't "mark" a location using magnetic sense - because all a compass gives you is a direction, not a position. (And a not very accurate (relatively speaking) direction at that.) On top of that, the direction varies over time. (See Magnetic Declination [wikipedia.org].)

      In school we all get this picture of Earth's magnetic field as a tidy and static system, when in reality it's anythin

      • Magnetic field has different strength in different area so you could (assuming no major changes have occurred) approximate distance from the polar region in addition to knowing the direction. Add to that a landmark or two ("2 days from the shore" or something) and you might actually have relatively good knowledge of where you are. Of course it isn't the exact spot but while I know nothing about sea turtles, I doesn't sound impossible that erring a dozen miles is acceptable and then they just use sound or wh

        • Magnetic field has different strength in different area so you could (assuming no major changes have occurred) approximate distance from the polar region in addition to knowing the direction.

          No you can't - because field strength does not vary linearly with distance from the polar region. Even if it did, since you can't measure East-West position with a compass - that still wouldn't work to fix a position.

    • That is interesting. If the poles shift, then it would be likely that turtles mating spots will drift over the years. I would think that would provide some interesting clues.

    • Re: (Score:3)

      by dissy ( 172727 )

      If you find and watch the BBC documentary "Richard Hammonds Journey To The Centre of the Planet", he visits a scientist performing experiments with turtles and magnetic fields.
      (Specifically, towards the end of part 1 of the 2 parts)

      They had a turtle velcroed in a vest so they could anchor it to a swing arm and let it move freely in a tank of water with full control of its flippers. The tank had boards along the outside with coiled wires which could induce a magnetic field.

      By flipping the polarity and chang

  • Inner Ear = Hearing? (Score:5, Informative)

    by ThunderBird89 ( 1293256 ) <zalanmeggyesi@y a h oo.com> on Friday April 27, 2012 @04:02PM (#39826399)

    Just because the signals originate in the inner ear, they aren't necessarily audio signals. The semicircular canals in my inner ear don't enable me to 'hear' the local gravity either.

  • and they can also read my thoughts

  • I hope we can learn from the observation and shrink our own compass and related technologies. Maybe in a century or so we'll be able to develop cellular implants, drop them on the brain, and see if and how effectively it can learn to interpret the signals.

    On that note, I hope we someday figure out that an organism can directly sense something we didn't previously observe or predict. Today I doubt our capabilities and understanding are developed enough to figure that out, even if it is quite commonplace. Nat

  • pigeon repellent? (Score:5, Interesting)

    by GreatRedShark ( 880833 ) on Friday April 27, 2012 @04:23PM (#39826697)

    I wonder if this could lead to a magnetic alternative to the netting that's used to keep pigeon's off of balconies?
    Some sort of a device that produces a magnetic field that pigeons find unpleasant...

    • Re: (Score:1)

      by Anonymous Coward

      All I see now is a pile of frothing, flopping pigeons.

  • Kinda reminds me of Roland following the lines in the Dark Tower series... creepy.

    And vastly off topic.

    -1 OT

  • I'm curious what the birds will do the next time Earth's magnetic poles switch [wikipedia.org]. Hopefully there's a "reset" button somewhere inside that tiny brain.

    • Re:Geomagnetic reversal (Score:4, Insightful)

      by blue trane ( 110704 ) on Friday April 27, 2012 @05:25PM (#39827413) Homepage Journal

      Since pigeons seem to have been around for at least 23 million years [avianweb.com], during which perhaps 40-50 pole reversals have occurred (according to the wikipedia article), they probably have some evolutionary method of dealing with it...

    • Last I heard the expectation was that a magnetic reversal would take something like a century and that during which time the field would not just disappear and then reappear in the other polarity, but instead do something more akin to the poles wandering around and ending up near the opposite spin pole from their former location. While the field strength might vary substantially as well, we wouldn't be completely without a direction-indicating field (though we might have east and west poles for a while and

  • but I didn't know it had ears of its own.
    Great story!

  • Individual neurons in birds' brains can relay crucial information about Earth's magnetic field, possibly providing the animals with an 'internal GPS'.

    You mean compass.

    • Individual neurons in birds' brains can relay crucial information about Earth's magnetic field, possibly providing the animals with an 'internal GPS'.

      You mean compass.

      The authors found that vestibular neurons — which are linked to balance systems in the inner ear — fired differentially in response to alterations in the field’s direction, intensity and polarity, and that these cells were especially sensitive to the bandwith that covers Earth’s geo-magnetic field.

      Combining information on direction, intensity and polarity could provide more than just a compass heading; it could be used to produce positional and directional information because of the way Earth's field varies in different locations. “It could theoretically be used as a GPS unit,” says Dickman.

      Newp, they most definitely mean, GPS. A compass will only provide limited
      directional data. GPS provides 3d data. Direction, intensity and polarity
      would suffice for 3d positioning, ala GPS.

      -AI

      • Newp, they most definitely mean, GPS. A compass will only provide limited directional data. GPS provides 3d data. Direction, intensity and polarity would suffice for 3d positioning, ala GPS.

        Humans have long used a compass-like device called a "diping needle", "dip needle" [kenyon.edu], or "dip circle" [wikipedia.org] to get a reading of "magnetic latitude" by measuring the angle of the earth's field relative to a horizontal plane.

        Inner ears have three-axis linear and three-axis rotational accelerometers. It would hardly be surprising

  • Perhaps these pigeons need some of the more esoteric devices out there to prevent exposure to emf smog: http://againsttheodds.hubpages.com/_12yk332elj2ci/hub/Electrosmog-5-Crazy-Devices-To-Protect-You-From-Electromagnetic-Wave-Pollution [hubpages.com]

  • Humans hear Magnetic fields [wikipedia.org] all the time.

  • Evolve that one from reptiles.
  • My biology teacher told me this in high school. That was more than 12 years ago. Yay someone confirmed the theory, but it is hardly tech news. In case anyone is interested and didn't know this, many plants and animals have this mechanism, but only migratory birds and a few others have it well developed enough to use it as a sense.

  • Not only does it explain how they get home, but also why they're in such a rush to do so. If someone were playing Jean Michel Jarre at me I'd do my best to get home as quick as I could too.

  • Just because the sense organ is in the ear doesn't mean that it is associated with the sense of hearing, just like our sense of balance comes from structures in the ear, but that sense is unconnected to hearing.

  • Just the same way we hear changes in bodily orientation, thanks to the semicircular canals, which are in the inner ear.

    I hear a kind of saxophone sound when spinning left about my vertical axis; in the opposite direction it takes on more of a clarinet tone.

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