Monday, August 25, 2008

Google Earth and alignment in cattle

Prof. Hynek Burda of the University of Duisburg-Essen spends much of his time studying the biology of mole rats. These fascinating little critters are nearly blind and otherwise adapted to life under ground. The naked mole rat, for example, is practically cold-blooded, lacks pain sensation in the skin and has a bee-like social structure. Some naked mole rats, evidently, are adept at matial arts.

Ansell's mole rats, on the other hand, tend to build their nests towards the south. That seems a bit odd for blind, burrowing animals. They're probably not using the direction of the sun as a cue. Other animals are known to be sensitive to the earth's magnetic field, so maybe that's it. And in fact, Ansell's tend to do worse in classic rat-in-maze tests in the presence of strong magnetic fields. What, if anything, this southward nesting is good for is a separate question. It may well just be a side effect of the clearly useful magnetic sense of direction.

Those south-nesting mole rats got Prof. Burda and company wondering if any other mammals had the same kind of sense (which has primarily been documented in non-mammals, such as birds and bees). And this is where the web comes in. First, they tried using Google Earth to see whether tents at campsites tended to be oriented (somehow, I would assume, factoring out any of several other reasons one might pitch a tent square to the world). That didn't work so well, but as so often happens they noticed something else.

Cattle, it seems, tend to graze lined up more or less north-south. It doesn't seem to matter where the sun is or where the wind is coming from, as long as it's not too windy -- if it gets really windy, cattle will face into the wind. It does matter, however, where you are on the globe. If local magnetic north is off of true north, as it is in the northeast US for example, cattle will also line up off of true north. In other words, they tend to line up along a magnetic north-south axis.

The next step, which no one has done yet, is to attach magnets to a few head of cattle and see if they line up differently then. It's not clear who's going to attach the magnets, but with school just starting, and with a little luck, an enterprising team might be able to convince some incoming freshmen it's a variant on cow-tipping. Stranger things have happened ...

[There was some controversy about this, with a second team unable to confirm the Burda's results, but according to this article on, there's probably something to it after all.  --D.H. June 2015]

1 comment:

Veronica Wald said...

Nicely summarized. Do you think there's grant money in there somewhere ;-)