onsdag den 27. august 2008

Cattle shown to align north-south

Glem kompas og GPS - tag en ko.

Forget about compass and GPS - grab a cow.


By Elizabeth Mitchell
Science reporter, BBC News

Have you ever noticed that herds of grazing animals all face the same way?

Images from Google Earth have confirmed that cattle tend to align their bodies in a north-south direction.

Wild deer also display this behaviour - a phenomenon that has apparently gone unnoticed by herdsmen and hunters for thousands of years.

In the Proceedings for the National Academy of Sciences, scientists say the Earth's magnetic fields may influence the behaviour of these animals.

The Earth can be viewed as a huge magnet, with magnetic north and south situated close to the geographical poles.

Many species - including birds and salmon - are known to use the Earth's magnetic fields in migration, rather like a natural GPS.

A few studies have shown that some mammals - including bats - also use a "magnetic compass" to help their sense of direction.

Dr Sabine Begall, from the University of Duisburg-Essen, Germany, has mainly studied the magnetic sense of mole rats - African animals that live in underground tunnels.

"We were wondering if larger animals also have this magnetic sense," she told BBC News.


Ingen kommentarer:

Send en kommentar