North And South

Here's a weird science story. I'm not sure I believe a magnetic field interpretation - sunlight could play a factor too:

Most cattle that were grazing or resting tended to align their bodies in a north-south direction, a team of German and Czech researchers reports in Tuesday's issue of Proceedings of the National Academy of Sciences.

And the finding held true regardless of what continent the cattle were on, according to the study led by Hynek Burda and Sabine Begall of the faculty of biology at the University of Duisburg-Essen in Germany.

"The magnetic field of the Earth has to be considered as a factor," the scientists said.

...The study sent Tina Hinchley, who with her husband Duane operates a dairy farm in Cambridge, Wis., to take a new look at an aerial photo taken of their farm a few years ago.

"The cows that were in the pasture were all over the place ... about two-thirds were north-south," Hinchley said.

Two-thirds is close to what the researchers found in their look at 8,510 cattle in 308 pastures. In the study, 60 percent to 70 percent of cattle were oriented north-south, which Begall termed a "highly significant deviation from random distribution."

Hinchley stressed that one factor that must be considered is cow comfort.

"They don't like to get hot. Their body temperature is 102, and they are wearing black leather jackets, literally! If turning north-south would keep them cooler, they would stand that way."

The research team noted that in very windy conditions cattle tend to face the wind, and have been known to seek out the sun on cold days. But they said they were able to discount weather effects in the study by analyzing clues such as the position of the sun based on shadows.

..."At one point last year the question came up whether large animals could also sense the Earth's magnetic field or not. But of course, it is difficult, or maybe impossible, to do these studies in the lab," she said. "So, the idea arose to look for other large mammals like cattle, and Hynek Burda was fascinated when he recognized that cattle could be found on Google Earth satellite images."

With satellite images they could tell the north-south orientation of the animals, but not whether an individual cow was facing north or south. You have to get closer to tell which end is which.