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August 26, 2008

Cows are magnets.

Hot off the press at the Proceedings of the National Academy of Science is an article about magnetoreception in cows and deer [1]. Begall and colleagues, perhaps having spent far too much time playing with Google Earth, noticed that grazing cows and deer [2] seem to slightly prefer aligning themselves N-S, like magnets in the Earth's magnetic field. From the abstract

To test the hypothesis that cattle orient their body axes along the field lines of the Earth's magnetic field, we analyzed the body orientation of cattle from localities with high magnetic declination. Here, magnetic north was a better predictor than geographic north. [3]

Time to rewrite the physics textbooks, I guess: Cows are spheres, yes, but magnetic spheres!


[1] S. Begall, J. Cerveny, J. Neef, O. Vojtech and H. Burda, "Magnetic alignment in grazing and resting cattle and deer." PNAS 105, 13451-13455 (2008).

[2] I was very disappointed, when I read through the article itself, to find no satellite pictures of cows aligned N-S. Indeed, there was not a single picture of a cow (or deer)!

[3] This is a good control to test the possibility that the E-W orientation of the sun drove the animals to prefer N-S in order to maximize the absorbed solar radiation. So, it seems that there really is some kind of weak magnetoreception going on. Now it's a matter of figuring out what biological compounds convey this magnetic sensitivity, and how its response to the Earth's field percolates up to behavioral tendencies.

posted August 26, 2008 10:59 AM in Things that go squish | permalink


Aha, shoule I adjust the orientation of my bed to have a nice dream?

Posted by: succc at August 29, 2008 12:50 AM

I actually am formulating a student project with a local zoologist to study synchronization of cows. (They tend to lie down at the same time.) Though I think we'll be ignoring the effects of magnetic fields...

P.S. The Facebook paper is almost ready. We might submit tomorrow. (I know---later than we thought. We have gone through multiple extra rounds of revisions to polish it. I was being too optimistic before, as usual.)

Posted by: Mason at August 29, 2008 04:18 PM

When you said synchronization of cows, I thought about synchronized swimming, which makes me think that it would a wickedly fun sport to have trained cow herds doing things in a synchronized fashion, and, of course, to have them wearing little speedo cow-caps. Extra points for synchronized cow pats.

Good luck with the Facebook paper!

Posted by: Aaron at August 29, 2008 09:40 PM