Why are cows magnetic?

[Reply]

I don't know why I never heard about this until today, but apparently the world's pastures are being eaten alive by throngs of bovine compasses. See the news story or study.

All over the world, apparently cattle herds tend to orient themselves along a north-south axis. They're even affected by magnetic declination and high-voltage power lines.

I can understand the use of magnetoception in migratory species or ones that travel over long distances, but... why cows? Why?!

[robert_columbia]

Mu

[Dervorin]

Originally Posted by robert_columbia

Mu

*Golf clap*

I feel it deserved at least that much attention. However, the fact that there's no element with the symbol Mu does rather spoil the joke, tragically.

[johnpost]

Originally Posted by robert_columbia

Mu

Originally Posted by Dervorin

*Golf clap*

I feel it deserved at least that much attention. However, the fact that there's no element with the symbol Mu does rather spoil the joke, tragically.

there is Mu-metal an alloy with high magnetic permeability.

might not have been aimed for though it hit the target anyway.

[Dervorin]

Originally Posted by robert_columbia

Mu

*Golf clap*

I feel it deserved at least that much attention. However, the fact that there's no element with the symbol Mu does rather spoil the joke, tragically.

[Malleus, Incus, Stapes!]

Originally Posted by Dervorin

*Golf clap*

I feel it deserved at least that much attention. However, the fact that there's no element with the symbol Mu does rather spoil the joke, tragically.

I thought he was speaking in Zen.

[Ale]

Originally Posted by robert_columbia

Mu

And this year's Polonius award goes to..... robert_columbia!

*Camera shots of runner-ups looking like they just sucked a lemon*

[Reply]

A 2011 followup study debates the findings, but a third party commentator says that the original results, “while mysterious, still stand”.

That article also contains what is now possibly my favorite phrase: "cows with unsatisfactory resolution"

[johnpost]

could be interaction with the cow magnets.

[MikeS]

Originally Posted by johnpost

could be interaction with the cow magnets.

Damn, you stole the joke I was going to make.

[Siam Sam]

Originally Posted by johnpost

could be interaction with the cow magnets.

This could have positive (heh) implications for high-school students and frat boys in their cow-tipping endeavors.

[heathen earthling]

Originally Posted by Reply

I can understand the use of magnetoception in migratory species or ones that travel over long distances, but... why cows? Why?!

Some wild bovids such as the bison and wildebeest are migratory. Are domestic cattle descended from a migratory ancestor?

[Der Trihs]

Originally Posted by heathen earthling

Some wild bovids such as the bison and wildebeest are migratory. Are domestic cattle descended from a migratory ancestor?

Possibly; they are descended from aurochs.

It is therefore possible that aurochsen living in several Mediterranean regions, sharing similar ecological conditions and belonging to a species with a large migratory potential, exchanged enough genetic material to maintain a certain degree of homogeneity.

[coremelt]

Originally Posted by Der Trihs

Possibly; they are descended from aurochs.

Are there any large herbivorous grazing animals in temperate climates which don't migrate?

AFAIK, the only grazing animals that don't are either native to tropical climates that don't have seasons or are too small to migrate. Anything that can, does, which makes sense the evolutionary pressure would have strongly favoured animals that moved north into the vast pastoral tundras in the north of europe in summer and then south into warm climates in winter.

Maybe there's no direct evidence but it seems to me pretty clear that the Aurochs would have had to migrate and so modern cows have some residual trait of a migratory urge.

[cmyk]

Modern cattle ranchers discovered a while ago that using electrified fencing and cattle prods was the most efficient way to get them to stick to the fridge.

Additionally, red meat is very high in iron.

[Askance]

Why are cows magnetic?

How attractive do you find them, exactly?

[coremelt]

fucking cow magnets, how do they work?

[cmyk]

I can't stand the Insane Cow Posse.

[jasg]

Originally Posted by cmyk

I can't stand the Insane Cow Posse.

Especially with guns... http://www.youtube.com/watch?v=FQMbXvn2RNI

[t-bonham@scc.net]

Growing up o our farm in west central Minnesota, the horses grazed facing south or east, mostly.

But not because of a magnetic sense effect. It's just that horses graze with their tails into the wind, and the prevailing winds on our farm were from the north or west.

Possibly the same is true of cows -- they tend to graze oriented based on the wind direction. And wind direction is fairly constant in most locations.

[Rachellelogram]

Originally Posted by t-bonham@scc.net

Growing up o our farm in west central Minnesota, the horses grazed facing south or east, mostly.

But not because of a magnetic sense effect. It's just that horses graze with their tails into the wind, and the prevailing winds on our farm were from the north or west.

Possibly the same is true of cows -- they tend to graze oriented based on the wind direction. And wind direction is fairly constant in most locations.

Is it so the breeze doesn't blow their tail hair back into their butts when they poop?

Originally Posted by cmyk

Hrmm, could be something to that.

Here's a cool "wind map" of the US that indicates wind direction from day to day.

Let it load for a minute, it traces out wind currents across the map; the results are actually really cool and fascinating. Makes America look furry.

Hehe, there's a cowlick in Nebraska right now.

[purplehorseshoe]

Originally Posted by rachelellogram

Is it so the breeze doesn't blow their tail hair back into their butts when they poop?

Hehe, there's a cowlick in Nebraska right now.

Ha! I never thought of that. In all seriousness, though, I believe it's so the wind isn't blowing into their faces - nostrils and eyes, especially.

[asterion]

Originally Posted by t-bonham@scc.net

Growing up o our farm in west central Minnesota, the horses grazed facing south or east, mostly.

But not because of a magnetic sense effect. It's just that horses graze with their tails into the wind, and the prevailing winds on our farm were from the north or west.

Possibly the same is true of cows -- they tend to graze oriented based on the wind direction. And wind direction is fairly constant in most locations.

Instinct for protection against predators? I'd buy that.

[cmyk]

Hrmm, could be something to that.

Here's a cool "wind map" of the US that indicates wind direction from day to day.

Let it load for a minute, it traces out wind currents across the map; the results are actually really cool and fascinating. Makes America look furry.

[TimeWinder]

Originally Posted by cmyk

Here's a cool "wind map" of the US that indicates wind direction from day to day.

Let it load for a minute, it traces out wind currents across the map; the results are actually really cool and fascinating. Makes America look furry.

Which leads directly to the best-named result in science: the hairy ball theorem. Based on more or less the same observation you just made, it's a proof that there must, at any given time, be a location of zero wind somewhere on the earth.

[Ludovic]

Originally Posted by TimeWinder

Which leads directly to the best-named result in science: the hairy ball theorem.

Since it involves cyclones, I wonder if that theorem is popular in Fort Wayne.

[Grey]

Originally Posted by Dervorin

*Golf clap*

I feel it deserved at least that much attention. However, the fact that there's no element with the symbol Mu does rather spoil the joke, tragically.

Oh it was better than that - μ

[Chessic Sense]

Originally Posted by Grey

Oh it was better than that - μ

I thought he was going for magnetic moment.

[MrDibble]

Has the study taken into account that the path of the Sun is generally E-W? So if you want to be warmed up by it, it pays to have your flanks to it.

[Colophon]

Originally Posted by MrDibble

Has the study taken into account that the path of the Sun is generally E-W? So if you want to be warmed up by it, it pays to have your flanks to it.

That's what I was going to say... but then you'd expect the cows to rotate throughout the day, facing roughly N-S at sunrise, then E-W at midday (at which point the sun will be in the south, in the northern hemisphere), then back towards N-S at sunset. Of course, the sun doesn't set due east except on the equinoxes, so the bovine angle would change through the year.

[Zulema]

Originally Posted by MrDibble

Has the study taken into account that the path of the Sun is generally E-W? So if you want to be warmed up by it, it pays to have your flanks to it.

I was thinking this also. If the cow wants the most amount of warmth on her skin she'll turn her side to the sun but that doesn't explain why in one group they always seem to be facing the same way and not facing each other occasionally.

[Corcaigh]

Originally Posted by Reply

All over the world, apparently cattle herds tend to orient themselves along a north-south axis.

I don't think I've ever noticed the cows around here only ever pointing on direction. I shall be on the lookout for this phenomenon and ask the dairy farmers that I know if they do!

[coremelt]

This is relevant:
http://summitcountyvoice.com/2012/04...ins-of-cattle/

[hogarth]

There was an episode of William Shatner's TV show "Weird or What?" where they investigated the claim. They weren't able to replicate it, I think.

[Chronos]

Of course they all face the same way: They're herd animals, and their greatest defense is the stampede. When everyone's facing the same way, you're ready to stampede at a moment's notice, while if some were facing the other way, they'd just get in each others' way come stampeding-time.

[njtt]

Even if cows do have a magnetic sense, that really does not explain why they would habitually use it to align themselves with the geomagnetic field. Do the birds that are actually known to have a magnetic sense align themselves with the field when they are not actually migrating? I doubt it.

Furthermore, one would expect that the apparently widespread use of cow magnets (which, I must admit, I only just learned about from johnpost’s and MikeS’s posts, above), would mess with any magnetic sense the cattle might naturally have. IIRC, magnetic sense in migratory birds was discovered when it was found that fixing a magnet to a bird messed up its sense of direction. The geomagnetic field is weak, and a strong alnico in a cow’s stomach ought to plenty enough to mess up any magnetic sense that might be there.

The suggested explanations in terms of prevailing wind or the direction of the Sun seem much more plausible (or, you know, it could all be just good old statistical artifact). It seems likely that cattle would be most in need of being warmed by the Sun in the morning, so they would tend to line up north-south then, to get it on their flank. By middle day, they might be warm enough, and not care, or even might want to avoid heating up much more and thus not want the Sun on their flank (which would again align them north-south). Note, also, that the result is not claiming to be more than a statistical, on-the-whole tendency, and I doubt whether they controlled for time of day when the satellite photos were taken, so cows facing randomly when it is not morning would probably just be written off as statistical noise.

[Der Trihs]

Originally Posted by njtt

Furthermore, one would expect that the apparently widespread use of cow magnets (which, I must admit, I only just learned about from johnpost’s and MikeS’s posts, above), would mess with any magnetic sense the cattle might naturally have.

I'd only heard of "Cow Magnets" as a Far Side joke; I'd no idea there actually were things called cow magnets.

[ruh-roh]

Originally Posted by njtt

Furthermore, one would expect that the apparently widespread use of cow magnets... would mess with any magnetic sense the cattle might naturally have.

I'm thinking it is the cows without magnets that stand pointing in semi-random directions. It is the ones with magnets that get pulled around to align with the magnetic field. What really pisses them off is the migrating birds that keep crashing into them.

[Quercus]

Originally Posted by njtt

The suggested explanations in terms of prevailing wind or the direction of the Sun seem much more plausible (or, you know, it could all be just good old statistical artifact).

I agree, especially since the effect -- if it exists at all -- appears to be so small that it's hard to replicate. Which means it's small enough that it would be hard to distinguish magnetic north from geographical north.

And you don't need fancy theories about cows turning sideways to the sun in the morning but not in the afternoon. The cows just need to always turn their butts to the sun. For cows in the northern hemisphere, this means they will on average be facing north.

I don't know much about cows, but I can imagine reasons for wanting to face away from the sun: don't want sun in the eyes, want to have grass lit from behind, instinctively want sun on the hindquarters to keep the butt UV-sterilized, etc.

[Reply]

I wonder if we can herd them with electromagnetic UAVs.

[Chronos]

Or of discontinuous wind.

[Reply]

So we've got:

1. Cows are magnetic because people have tailbones (i.e. evolution isn't 100% clean)
2. Cows don't like to poop into the wind
3. Cows like to sunbathe
4. SOME cows are magnetic and the rest like to stampede

I might have to make this my senior thesis, heh.