Slashdot Mirror
Pigeons May 'Hear' Magnetic Fields
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."
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.
God spoke to me
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.
Hyperbole: I use it liberally!
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. Nature is a beautiful innovator, and we have a lot to learn from it.
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...
how does it sound?
The same as one hand fwapping.
If God forks the Universe every time you roll a die, he'd better have a damned good memory.
Kinda reminds me of Roland following the lines in the Dark Tower series... creepy.
And vastly off topic.
-1 OT
https://www.accountkiller.com/removal-requested
It is common knowledge. How it works is not.
I don't need no stinking pocket protector. I just carry a lot of dead pens in my pocket so I look cool.
I'm curious what the birds will do the next time Earth's magnetic poles switch. Hopefully there's a "reset" button somewhere inside that tiny brain.
but I didn't know it had ears of its own.
Great story!
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
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
You mean compass.
There are audio recordings of the rapid changes in the Earth's magnetic field at points on the ground.
http://www.ab9il.net/vlf/vlf1.html
Various events also have their own sounds:
http://www-pw.physics.uiowa.edu/mcgreevy/
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
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.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
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
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.)
In school we all get this picture of Earth's magnetic field as a tidy and static system, when in reality it's anything but.
Humans hear Magnetic fields all the time.
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.
I prefer the "u" in honour as it seems to be missing these days.
Evolve that one from reptiles.
Cranky educator.
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.
Task Mangler
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.
Technoli
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 changing the magnetic field, the turtle would turn around and swim towards the other side of the tank.
The earths magnetic field is in fact many times larger than the earth itself, and while our compasses only show direction along the field lines, its possible to get your bearing north/south by the strength of the field. The field is quite uneven as well, so while it might not be possible to perform GPS levels of navigation, the strength of the field can indicate which area you are in along all directions.
Turtles use this to return to their birth place as you say, and this has been proven both by observation and by experiments.
Well worth the watch if you can locate the documentary.
Perhaps that's why pigeons appear to be so fucking stupid; if I had that racket going on in my head all the time all the time all the time voices voices never stopping never stopping in my head never never stopping I'd go a tad scatty.
Shitting on anything that doesn't move is probably the only way to vent their frustration.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
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 whatever to locate each other after days of searching.
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.
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.
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.