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."

Comments

I wonder if this is the same case for sea turtles

[GoodNewsJimDotCom]

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.

Inner Ear = Hearing?

[ThunderBird89]

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.

Re:Inner Ear = Hearing?

[Forty Two Tenfold]

Which pigeons? European or African?

pigeon repellent?

[GreatRedShark]

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:I thought this was common knowledge

[batrick]

It is common knowledge. How it works is not.

Re:Geomagnetic reversal

[blue trane]

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

Re:CmdrTaco "hears" when I cum in his mouth.

[mikael]

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/

Re:I wonder if this is the same case for sea turtl

[mikael]

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.

Re:I wonder if this is the same case for sea turtl

[DerekLyons]

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.)
 
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.

Re:I wonder if this is the same case for sea turtl

[dissy]

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.

Re:CmdrTaco "hears" when I cum in his mouth.

[Hognoxious]

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.

There is a position... Just one dimension, though

[F69631]

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.