The web was recently buzzing with the discovery that cattle (and other herd animals, such as red and roe deer) tend to situate themselves on a North-South axis, as if involuntarily directed by the earth’s magnetic field lines to the poles. It all came about when German scientists were using Google Earth to analyze herding patterns and behavior. Thousands of years of human ignorance, gone in a single Google moment.

Image via DEMOSH

But it’s not just cattle and deer that are affected by the earth’s magnetism. Scientists have previously discovered that birds, bats, turtles and salmon (among other fish) are affected by “animal magnetism”. Lobsters have been shown to exhibit magnetic sensitivity, relying upon the earth’s magnetic lines to navigate.

Images via m00by and longhorndave

The aforementioned bats actually have bacteria in their bodies which, through evolutionary natural selection, has been favored due to its beneficial role in magnetic sensitivity. But, being humans, scientists have also been curious to find out if homo sapiens are affected. Since testing would be near-impossible, they looked to other large mammals, such as the humble cow, to gather further evidence.

Images via Cesar Rincon and PaysImaginaire

Baby sea turtles rely on the earth’s magnetism to make their way to and fro in the Atlantic Ocean (that’s 8,000 miles round trip). There’s a major current that spans the Atlantic that scientists have learned baby turtles can actually “read”. Their bodies tell them when they’ve strayed off course – it’s just like having an internal GPS. Even more astonishing, birds can literally see the earth’s magnetic field. Though it’s not conclusively proven, there is compelling evidence: birds’ eyes contain specialized light receptor molecules that communicate with the visual center in the brain. Just as a compass relies on a tiny magnet to “tune in” to the earth’s magnet, birds’ eyes may act as compasses as well. Bird brain, indeed.

Image via Martini Captures

But what about humans? Despite many alternative health industry claims that our cell phones, homes and highways are veritable minefields of electro-magnetic danger, the WHO (World Health Organization) and the scientific community maintain that such claims are bogus. The available scientific literature does not offer any meritable evidence that magnetism harms us; but how it affects us is still being explored. There is some interesting treatment research for electro-magnetic therapy’s usefulness, particularly in helping scientists to understand how the human brain works. And if simple chemical reactions can be affected by the earth’s magnetism, couldn’t our bodies?

Image courtesy NASA

The earth’s magnetic field itself is fascinating. Steady as you might think it is, the magnetism of the planet is remarkably capricious. Every few million years or so, it flips. It sloshes. And its power is fading. In certain parts, the magnetic fields are so weakened that the area is at risk of greater radiation. In fact, scientists believe the North and South poles could one day switch. Such fluctuations in magnetism may help to shed light on why geological phenomena like earthquakes and tsunamis are often detected by animals well in advance of people.

Image via gripso_banana_prune

The evidence is interesting in that it extends from fishes and birds to mammals. With terrestrial magnetism serving to help guide animals, does this mean that earthly creatures are mere magnets upon a giant metal ball? Shelve science fiction fantasies for now. Though many animals have developed distinctive features – from heritable bacteria to special eyesight to an internal GPS – one might think of terrestrial magnetism and its impact upon animal evolution and behavior as one remarkably synergistic story.

Image via Valerie Everett