Do Cows Always Face North to Graze?

I'm not sure which is stranger-- the fact that cattle always face North to graze, or that humans somehow failed to notice it until the advent of the internet.
A detailed analysis of Google Earth images found that cattle in North America almost always face the same direction-- North-- when they are grazing. Only a few "watchdogs" in the herd will face the opposite diretion. Researchers found that over 8,510 grazing cattle in 308 pastures all around the world agreed on one thing-- it's cool to face North while you're eating.
After reading about this study, I double-checked every time I saw a herd of grazing cattle. Invariably, when I see cows grazing in my area, they are facing North. How have hunters, herdsmen, farmers and old wives totally neglected to notice this until now?
No one is certain about why cattle face North to graze, but it clearly relates to a cow's internal "compass." The cattle face magnetic North or South depending on the hemisphere in which they are grazing. In South America and South America, where the Earth's magnetic field is weakest, cattle were tilted a bit to the west. However, most grazing cattle maintained their North-facing diretion regardless of the weather, sunlight and season.
Since there are no humans who are fluent in cow, we can't be entirely sure of why they have developed this odd adaptation. It could somehow relate to predator avoidance or to now-extinct migrating instincts. It's quite possible that cows faced North hundreds or thousands of years ago because it served an important purpose in the animals' survival. However, there's no clear benefit to the odd habit, as far as we can see now.
To me, there's something oddly reassuring about the simple realization that cattle face North to graze. It reminds me that, no matter how advanced our technology becomes, there are still minor discoveries that we can make in our own mundane, day-to-day world. And, no matter how many scans, studies and satellites we make, we may never know why (or how) our fellow animals do the things they do. No amount of technology can eliminate the limitless wealth of discovery within the natural world.