A splendid report in Nature reveals a great secret about the cow. It has a compass. To be more precise, a wide-ranging study of cow herd orientation as revealed by Google Earth has shown a statistically significant correlation between the North Pole and the way cows like to stand in the field – magnetic or arable.

The researchers have diligently tried to exclude other factors such as alignment side-on to the sun for warmth or the presence of water or other cow-attractive features. They also looked at deer and found similar preferences. No matter how they've tried to pick holes, the figures – like the cows -- stand out. For a start, the cows are aligned to magnetic, not geometric, north: other evidence hints that near power lines, where magnetic fields are scrambled, the cows are similarly pointless.

It is unclear, the Nature report says, what evolutionary advantage is conferred by this bovine behaviour. Hard to argue with that. Perhaps it's some relic of an old migratory sense, or a new trait brought on by interference with the cow's higher cognitive functions by GPS irradiation. (I made those two ideas up. Anyone who knows cows knows that higher cognitive functions are rarer than steak tartare.)

But I choose to see it as a rediscovery of old folk knowledge. My evidence is the existence of pubs called The Goat And Compasses, an old name currently held (apparently erroneously, on inspection) to be a corruption of God Encompasseth Us, a motto from Cromwellian times. I think not. I think this is the preservation of ancient lore, where sturdy voyagers found their way through tractless lands by observing which way the north end of the nearest goat was actually pointing.

It's very cheering that a wild convergence of the Internet, satellite imaging, Google's business plan, and the ubiquitous PC is revealing such signs of our distant past. I look forward to the discovery of television among the bees, and proof that a decent pork chop can be used to detect gold. It may even be possible to train our domestic pets not only to guide us along the streets, but to give us turn-by-turn directions in our cars. Ladies and gentlemen, I give you CatNav.