Follow Slashdot blog updates by subscribing to our blog RSS feed


Forgot your password?

Special Molecule Gives Birds a Magnetic Biocompass 276

Aaron Rowe writes "CORDIS news reports that a team of scientists has identified a family of molecules called cryptochromes that allow migratory birds to sense magnetic fields. Curiously enough, these molecules only function when accompanied by blue light. The article also mentions, 'The researchers also suggest that, as cryptochromes have been strongly conserved throughout evolution, all biological organisms could have the ability to detect magnetic fields, even if they do not use them.'"
This discussion has been archived. No new comments can be posted.

Special Molecule Gives Birds a Magnetic Biocompass

Comments Filter:
  • Hrm... (Score:5, Funny)

    by PieSquared ( 867490 ) <isosceles2006@gma i l .com> on Monday September 11, 2006 @09:41PM (#16086045)
    Where do I sign up to get these powers enabled? I totally would go for it, even if it is a really lame 6th or 7th sense. Like, if I was lost in the woods with no cell phone and nothing to make a shadow with, and no running water... it could be mildly useful!
  • by WindBourne ( 631190 ) on Monday September 11, 2006 @09:46PM (#16086063) Journal
    When he gets off the plane at DIA, his first question is which way to north. Once he has his berings, he always knows his directions. Even when traveling through the mountains, day or night, he is able to figure out the direction quickly. Pretty impressive. What I find interesting is that plane travels screws him up. Once on the ground, If he does not get his bearing quickl, he appears to get more uncomfortable as time passes.
    • by smilindog2000 ( 907665 ) <> on Monday September 11, 2006 @09:56PM (#16086116) Homepage
      We do have a built-in gyroscope, though not a compass. I'm pretty sure guys have a stronger sense of it then girls. Makes sense... hunting and all.

      I have a good sense of direction, but now and then I get all messed up. It's a really strange feeling when I realize this has happened, and the internal gyro has to flip 180 degrees. There's a sense of the world shifting, almost like motion.
      • by fotbr ( 855184 )
        I can usually find north, though I like to think I have a built in Inertial Guidance System rather than something as simple and mundane as a gyroscope and compass.
      • by Wizarth ( 785742 )
        I have much the same thing. But I also have a special case.

        First time I visted a friends house, it was night time, and my sense of direction got flipped (I also wasn't driving). It now seems to be stuck that way. I can drive out there and tell exactly when my sense of north does a 180. Driving through a cutout in a hill, can't see anything but the sides of the trench, when coming from one direction, and from the other direction its a set of curves that are bounded in by dense trees.

        So, gyroscope, yes, but i
      • by WindBourne ( 631190 ) on Monday September 11, 2006 @10:05PM (#16086153) Journal
        This guy is able to tell you north, south, east, and west in mountain canyons, or even in buildings. He is not able to give degrees, but he can point in roughly 30-45 degree increments. Pretty impressive. Over the years, I have been impressed with some capabilities. One guy that I knew had 6/20 vision. He had doctors everywhere wanting to study his eyes. But he wanted to be a pilot so told them to take a hike.
        • by Doc Ruby ( 173196 ) on Monday September 11, 2006 @11:42PM (#16086471) Homepage Journal
          6/20 vision [] (assuming you're using the British/meters notation) means your friend had to stand 6 meters from something that others can see clearly at 20 meters. The only doctors wanting to study those eyes would be optometrists wanting to sell him glasses.
          • by ceoyoyo ( 59147 )
            He probably meant 20/6 vision which is pretty good but not cyborgish or anything. My eyes are somehwere in the neighborhood of 30/20... with my contacts.
            • 20/6 vision would indeed be cyborgish, as noted in the Wikipedia article to which I linked: "the maximum acuity of the human eye without visual aids (such as binoculars) is generally thought to be around 20/10 (6/3)".
              • by ceoyoyo ( 59147 )
                You are correct. I was converting into x/20 format, which is what is usually quoted here. I did bad math.
        • I don't know why you're quite impressed by this. You're quite impressed by him navigating his way through mountains? Well how about a featureless, vast desert. It's quite commonplace amongst desert nomads.
      • by Phleg ( 523632 )
        I take MARTA (Atlanta transit) into school every day. Once, I had to use a station I'm not familiar with. I normally have an impeccable sense of direction, so I get up on the platform and go to the "Southbound" side. I zone out, the train comes, and I hop in and open a book. About 15 minutes later, I hear the conductor say this is the last Northbound stop, which makes me do a double-take. Even returning to that station later in the night, and trying to figure out the direction I'm facing based on how I drov
      • Knowing which way to go... guys have a stronger sense of it then girls

        My wife has anti-sense. I've been married 20mumble something years (to the same woman) and on those occasions where I can observe her sense of direction, it is almost always wrong (i.e. walk into the parking lot and she will forcefully walk in the opposite direction of the car. Of course, having been married this long, I just walk to the car and let her eventually find the way... sometimes even admiting "right again, dear.").

        Anyhow, s

      • I also find that once I have been a place I can *always* get back there... except in LA. Whats up with that!? I get really lost in LA. Walking around Manhatten, NY - no, Greater San Francisco Bay area, No.. In Kansas City MO, no... LA lost lost lost...
      • Re: (Score:3, Insightful)

        by AhtirTano ( 638534 )

        I'm pretty sure guys have a stronger sense of it then girls. Makes sense... hunting and all.

        And the female job of gathering fruit, vegetables, and herbs from remote areas of the forest or savanah or whatever doesn't require a sense of direction.

    • Even when traveling through the mountains, day or night, he is able to figure out the direction quickly.

      Use of the sun by day or stars by night.

      What I find interesting is that plane travels screws him up. Once on the ground, If he does not get his bearing quickl (sic), he appears to get more uncomfortable as time passes.

      Jetlag or simple fatigue from air travel.

    • When he gets off the plane at DIA, his first question is which way to north.

      Tell him to look at the mountains and turn right...


    • by OverlordQ ( 264228 ) on Monday September 11, 2006 @11:47PM (#16086487) Journal
      When he gets off the plane at DIA, his first question is which way to north.

      Um, if he actually could sense the magnetic field, he could tell which way was north and which was south. Thank God we dont have to tell magnets which say is 'North' to get them to work.
      • Thank God we dont have to tell magnets which say is 'North' to get them to work.

        Man, I just knew them damn Microsoft® Magnets(TM) I bought were defective... now I'm going to have to call in an RMA.

    • Probably a coincidence, but every time I cross the equator in a plane, my 'sense of direction' gets completely screwed up. Coming from Australia to LA, after crossing the equator (approximately), my brain starts to scream at me that I'm heading southish, rather than northish.

      I never really noticed a sense of direction, until it started to go haywire. Normally takes me 12-24 hours to adapt back to 'normal'.

      As I mentioned, it probably has absolutely nothing to do with inbuilt compases, but it's certainly sli
  • Radio (Score:5, Funny)

    by Spazmania ( 174582 ) on Monday September 11, 2006 @09:47PM (#16086067) Homepage
    And since radio is just a modulated electromagnetic signal, we should be able to pick up Rock 'n Roll on our teeth by exposing them to blue LEDs. It remains only to train our brains to understand this new sixth sense...
  • by Centurix ( 249778 ) <> on Monday September 11, 2006 @09:47PM (#16086068) Homepage
    Where he was reading Brief History of Time and read "light is effected by gravity", to which he concluded that it was easier to drop things in the dark.

    -1 offtopic.

    Mind you, maybe I could strap a blue LED to an albatross and find my way home when I'm drunk.

    +1 ontopic.
    • by njh ( 24312 )
      Actually, light is effected by photons. It is, however, affected by gravity.
  • by smilindog2000 ( 907665 ) <> on Monday September 11, 2006 @09:51PM (#16086088) Homepage
    I hope they don't get too confused: 5/1544240 [] _South_ []

    No wonder those latent genes are turned off.
    • by FleaPlus ( 6935 ) *
      What's interesting though is that there doesn't seem to be any fossil evidence of higher-than-normal extinction rates during previous pole reversals...
    • Re: (Score:3, Insightful)

      by nwbvt ( 768631 )

      Well despite what movies like The Core will make you believe, its not like this is their only way to tell where they are going. I believe they primarily rely on sight and memory, they are not just flying around there with their eyes closed.

      Of course there is only one way to find out for sure. Tie big magnets to the bird's heads and see if they can still find their way South. If not, we know it plays a big role in their navigation. Either that or it weighed them down so much they couldn't fly.

  • Hey birds! (Score:5, Funny)

    by cryptochrome ( 303529 ) on Monday September 11, 2006 @09:52PM (#16086093) Journal
    I'm way ahead of you.
  • I know birds aren't smartest creatures, but I don't remember if they can memorize there migration path (though I assume not.) Could the hightening of this magnetic sense during certain seasonal light conditions direct the birds to follow the earth's magnetic field, guiding them until they encounter an area with lighting conditions sufficient to disrupt the sense?
  • F=IL X B (Score:5, Insightful)

    by afmstuff ( 954673 ) on Monday September 11, 2006 @09:55PM (#16086110)
    This is interesting in the sense that these are very low frequency (~0Hz) fields which transfer much less power to the molecule which interacts with it than say visible light which operates at a much higher frequency and is comprised of a coupled electric and magnetic field. Of course the latter has been known to be sensed by sighted animals for quite some time. One way to view this is as an extension of the mechanism of vision- a photon causes a fast (actually one of the fastest reactions known) trans->cis conformational shift in retinol which drives a voltage down the optic nerve... the mechanism described in the FTA is the next step: once a radical is formed, it responds in a magnetic field. Apparently this response is also sensed. Interesting finding!
  • Iron in your nose (Score:5, Informative)

    by TubeSteak ( 669689 ) on Monday September 11, 2006 @09:57PM (#16086121) Journal
    According to []
    • There's a compass in my nose?

    • All humans have a trace amount of iron in their noses, a rudimentary compass found in the ethmoid bone (between the eyes) to help in directional finding relative to the earth's magnetic field.

    • Studies show that many people have the ability to use these magnetic deposits to orient themselves-even when blindfolded and removed from such external clues as sunlight-to within a few degrees of the North Pole, exactly as a compass does.

    • Though no one knows how this "sixth" sense is processed by the brain more then two dozen animals, including the dolphin, tuna, salmon, salamander, pigeon, and honeybee have been found to have similar magnetic deposits in their brains to help them in navigation and migration.

    I will dispute their statement about pigeons though. I recall watching or reading something where the scientists put trackers on homing pigeons to discover how they found their way around. Turns out they follow landmarks.

    The pigeons often took indirect routes, because they were following a road. The scientists didn't figure this out even after they realized the paths were very odd... it didn't click until someone looked at a road map.
    • by Centurix ( 249778 ) <> on Monday September 11, 2006 @10:06PM (#16086161) Homepage
      With a nose the size of mine I'm not looking forward to the polar shift. I'll have to wear kneepads and a helmet.
    • I will dispute their statement about pigeons though. I recall watching or reading something where the scientists put trackers on homing pigeons to discover how they found their way around. Turns out they follow landmarks. The pigeons often took indirect routes, because they were following a road. The scientists didn't figure this out even after they realized the paths were very odd... it didn't click until someone looked at a road map.

      One doesn't disprove the other. Just because they navigate using land
  • by DrLudicrous ( 607375 ) on Monday September 11, 2006 @09:59PM (#16086128) Homepage
    Anecdotally, I have heard of many people "sensing" the magnetic field of an MRI scanner. I have had a few MRI's done on myself, and can attest to this feeling. It is strange, mostly in the head, somewhat like when one feels dizzy or just a tinge of seasickness. I think that is has something to do with the fact that as you enter the scanner, the field you experience changes quite rapidly. Once you are in the scanner, I haven't really noticed the queasiness as much, though it still feels strange. However, I attribute this second sensation more to the fact that one is contained inside a small tube with all kinds of weird noises and vibrations going around. So at the very least, some people seem to be sensitive to changing fields above some threshold.
    • Re: (Score:3, Funny)

      by ScrewMaster ( 602015 )
      Usually that sensation is followed by the sound of a metal plate ripping through the back of your skull and adhering firmly to the inside of the scanner.
    • Re: (Score:3, Informative)

      by lukesl ( 555535 )
      The same thing happened to me once, when I was working to prepare an MRI scanner for an experiment. There was a radiologist there, so I asked him what the mechanism was, and he said it was believed that the magnetic fields affect metal ions in your otoliths [], which are the organs in the inner ear responsible for sensing motion. Apparently it's known that some fish and birds have magnetic materials in their otoliths, but I'm not sure if it's ever been demonstrated directly in humans.

      Also, it's known that
      • You do realize that the main purpose of the MRI is to put a "moment" or torque on the bound cellular water? When the water returns to its rest state it emits radiation that is detected for the pretty pictures. You might be feeling that effect as there is vastly more water in your body than metal ions.
        • by DrLudicrous ( 607375 ) on Monday September 11, 2006 @11:00PM (#16086337) Homepage
          You are right in some respects. The moment to which you refer is the nuclear magnetic moment of the hydrogen atom, which are quite plentiful in most living things, ourselves included, due to the prevalence of water. In MRI, the torque these moments experience causes them to change their alignment from being in the same direction as an externally applied magnetic field (hence the big MRI magnet), to one that lies perpendicular to the direction of the external field. As they do this, the precess about the external field axis at a rate called the "Larmor frequency" (i.e. they rotate about it). This causes the magnetic flux inside the MRI receiver coil (more or less a loop of wire) to change, and by Lenz's Law, an EMF (voltage) will be induced. This is the signal that is detected.

          Note that while the magnetic moments are being manipulated, the actual water molecules themselves are more or less unaffected. This is one reason that MRI/NMR is such a great way to measure molecular self-diffusion- the phenomenon of diffusion is unaffected by all the magnetic fields being bandied about the sample. So to sum up, the "torque" the water molecules experience is one that affects only the magnetic orientation of the hydrogen atoms in your body, and not the actual physical orientation. And the signal that an MRI machine detects is not coming from the return to equilibrium of the water molecules as much as it comes from the precession of the asffected magnetic moments about the direction of the external field.

  • midichloreans joke yet?
    • by SamSim ( 630795 )
      Oddly enough, electromagnetic fields do indeed surround us, bind us, and hold the universe together. Gravity, too, of course, but it's very small-scale electromagnetic effects which stop you flying apart into a cloud of free atoms.
  • Why Blue Light? (Score:4, Interesting)

    by NexFlamma ( 919608 ) on Monday September 11, 2006 @10:31PM (#16086234) Homepage
    They mention the blue light necessity of this system, but they never really explain why it has to be blue light or what the light itself does (unless I've become illiterate). Can anyone explain (or at least make something plausible up) the whole blue light component of this mechanism?
    • by aXis100 ( 690904 )
      "The scientists realised that the cryptochromes could well be involved in the perception of the magnetic field, as they have all the physical and chemical properties needed, notably the absorption of blue and green light and the formation of 'radical pairs' - molecules which respond to magnetic fields."

      So blue light must have the right energy level (see quantum physics) to interact with the molecule's electrons and cause the change.
    • In some bacteria the enzyme photolyase [] works to repair thymine dimers (from UV DNA damage) but requires light in the visible spectrum.

      It's probably a protein with a magnetic ligand that requires a specific energy to activate. Of course I wouldn't actually read the article.

      -Ed []

    • Re: (Score:3, Interesting)

      by IorDMUX ( 870522 )
      The current theory is that certain (blue-ish) frequencies of light create radical pairs--charged particles--that are affected by the Earth's magnetic field. Some (unkown, I believe) mechanism detects the effect on these particles (perhaps a Hall voltage?) and interprets that as magnetic field information.
  • by Anonymous Coward on Monday September 11, 2006 @11:14PM (#16086383)
    I've know for a long time that many large birds freak out when a red laser pointer is shown anywhere near them. Especially large parrots. I'm not talking about pointing in their eyes, which is cruel to any animal. But just shining the red light nearby is enough to agitate them, and if shown near their head they will lose balance and fall from their tree.

    These light sensitive molecules must be very important to the bird's balance as well as helping them migrate. I wonder if they use the magnetic field to remain upright as well, or if by the red light turning off the receptor magnetic-sensitive light receptor molecules, they temporarily go blind. REd light could be perceived to be much brighter to them than the other colors. Since if the red light shuts off the receptors, only a small amount must be blinding. It might be like flipping a light switch where all blue and green perception disappears and only red is left. I"m glad my eye's aren't affected by specific colors that way.
  • If blue light is an important factor, would that mean that the ability to navigate goes down towards dusk? Sounds like an experiment is needed.
  • How is this news. This all sounded really familiar and old, and of course, the first site I went to on a google search took me to this [] from 2000. There's tons of stuff from 2004 on studies done with pidgeons. But this stuff is definitely not new.
    • studies done with pidgeons

      Walter was studying the Krell, right?


    • by Alfred, Lord Tennyso ( 975342 ) on Tuesday September 12, 2006 @12:57AM (#16086676)
      It's a very badly written press release. In fact the actual science has zilch to do with birds and everything to do with plants using the same molecule. They described the way light and magnetic fields interact to change the way the plant stem grows, except in plants without the cryptochrome molecule.

      Which is just basic, everyday scientific advancement: a very small and excruciatingly dull thing, presented with a tie-in to something more interesting in an attempt to look sexier and get funding. Scientists hate doing it, but if you want to keep doing science, that's what you do.

      This article IS news, but only in the narrowest sense: new information. But after you take that new information, tie it in to something more interesting but only indirectly related (which you put at the front of the press release, and the actual new stuff at the end), then summarize it for Slashdot (skipping the stuff at the end), "news" becomes "olds".

      One final note: when I call the work "small", I don't mean to dis the grad students who worked thousands of hours tending the plants, measuring them, putting that data into the computer, analyzing that data, probably cutting them open and measuring that... such immense grunt work for a minor advance [promptly blown up into something irrelevant by university's press department] is the heavy-lifting of science. It's gotta be done but it's not glamorous or even interesting.
  • Only truly deviant birds would choose to ignore such a great gift. Many suburban and urban geese (in vast numbers), as well as some species of cranes and other birds have thrown off the shackles of cryptochromes and chosen to stop migrating. Why buy the cow when you Get [] the milk [] for for free? [][google cache of The Wall Street Journal]
  • The Cell Phone companies and the Electrical Power Transmission companies have done studies, and those studies say that electrical fields can't possibly affect biological tissues.

    No matter what goofy molecules ducks use to find their way to fly south for the winter.
  • by Chacham ( 981 ) *
    Birds? Blue-Light?

    Q: What did the bird say when it flew over K-mart?
    A: Cheap, cheap.

  • Yes you can. Just remove the cryptochromes and see if they can find their way. I'm sure we could just sew them back on afterward.
  • Sever the nerve associated with the little deposit of magnetic gunk, they still fly home more or less. Sever their olfactory nerve, and they get hopelessly lost.
  • by Fantastic Lad ( 198284 ) on Tuesday September 12, 2006 @01:24AM (#16086768)
    Why does everybody assume that the trigeminal nerve (or this newly discovered molecule) in homing pigeons is used for navigation?

    Is it because we have learned how to use magnetics for navigation, so we therefore assume that animals capable of sensing magnetic fields must use it for navigation as well? The problem is that this is a false assumption.

    --Birds can sense magnetic information. However, when the olfactory nerve is cut, they get lost even when the trigeminal nerve remains intact. Birds which have had the trigeminal nerve cut but which had the olfactory nerve left intact could find their way home. So the claim is that being able to sense magentic fields was not required for homing pigeons.

    Still, it is generally accepted that homing pigeions have the wetwork required to sense magnetic fields. And if not used for navigation, then what? Why did such a sense develop?

    Put another way, what other perceptive planes of information exist which might make being able to sense EM fields useful?

    ALL organisms might have this ability?



    • We should be training these birds for credit card validation...

      One quack good/accepted, two quacks bad/rejected.

      Definately better than those stupid card swipe machines!
  • by Splinton ( 528692 ) on Tuesday September 12, 2006 @03:32AM (#16087044) Homepage

    According to a recent New Scientist article [], homing pigeons use their nose to find home rather than the Earth's magnetic field.

    From the article:

    She released 48 inexperienced homing pigeons 50 kilometres from their home loft. Half of them had had their olfactory nerve severed and half their trigeminal nerve, which is responsible for magnetic navigation. The next day, all but one of the birds deprived of their trigeminal nerve had returned home. Only four without a sense of smell returned (The Journal of Experimental Biology, vol 209, p 2888).

  • The guy on the following website [] says get got the power of magnetic vision using magnetic implants. Now I don't know if this really works but I found it interesting.

    -- I forgot what my tag line was supposed to be... but I forgot... but it was good... real good.... laughing just thinking about it.
  • the article gives a link to the french research agency cnrs, but that seems to be a dead end..anyone have a clue where the real science is posted

"If it's not loud, it doesn't work!" -- Blank Reg, from "Max Headroom"