CATTLE COMPASS
Image: J. Cerveny / Courtesy of Sabine Begall
-
What a Plant Knows
How does a Venus flytrap know when to snap shut? Can it actually feel an insect’s tiny, spindly legs? And how do cherry blossoms know when to bloom? Can they...
Read More »
Forget cow tipping—next time you want to mess with a bovine friend, try waving a magnet in its face.
Researchers have found that when grazing or resting, cattle and deer tend to point their bodies toward Earth's magnetic poles, which suggests they are able to sense magnetic fields in the same way as many smaller animals.
German and Czech researchers used Google Earth satellite images to look at 8,510 domestic cattle in 308 pastures located randomly across six continents. They also studied body alignment in 2,974 red and roe deer in the Czech Republic, either by photographing the animals or checking the impressions they left in snow.
The team reports in Proceedings of the National Academy of Sciences USA that the animals tended to point north or south but not in other directions. When the researchers were able to examine the position of the head in the case of red and roe deer, they found the animals tended to point north.
The group ruled out other reasons, such as wind or sun, for why grazing animals might orient themselves that way. There was no consistent wind pattern among the different locations, study author Hynek Burda, a zoologist at the University of Duisburg–Essen in Germany, says. And if the animals were basking in the sun, researchers would have seen them standing outside of one another's shadows.
More tellingly, in places such as the coastal U.S. where the direction of the magnetic north pole differs from geographic north (the latter defined by Earth's axis of rotation), the group found that cattle positioned themselves toward the magnetic poles.
Researchers have found evidence for a magnetic sense in animals ranging from fruit flies to mice and mole rats to fish, amphibians and birds (but not humans). The study shows that "the magnetic sense is virtually ubiquitous," says sensory biologist John Phillips of Virginia Polytechnic Institute in Blacksburg, who has studied it in other animals. "It's not simply in the realm of animals that move very large distances."
The sense can come from small magnetic particles in cells, but some animals such as birds also seem to perceive magnetic fields as changes in light intensity, due to effects of the fields on light-sensitive pigments in the eye.
To look for a magnetic sense in larger animals, the group's first idea was to study camping humans, Burda says. "We wanted to study some kind of spontaneous behavior, because learning experiments can sometimes become very frustrating," he says.
Migratory animals may use the ability to get a sense of direction or construct a map in their heads for navigating, according to Phillips. Evidence for a magnetic sense in cattle and deer suggests to him that it may be a more basic tool for mentally mapping their everyday surroundings and learning new landmarks. "I think it'll…make us rethink what this kind of sensory ability is used for," he says.
It may also come in handy if you're ever lost in a cow pasture.
See what we're tweeting about
15 Comments
Add CommentI viewed Google Earth and discovered that upon viewing coastal beaches, that human beings align with east-west magnetic lines when sunbathing.
Reply | Report Abuse | Link to thisPoint?
The animals may align themselves that way to keep warm by exposing more surface area to the sun.
Most grazing animals move into the prevailing winds while grazing and during their rest periods face into the winds to keep flies as well as what's around them for the scent funtions to work.
Reply | Report Abuse | Link to thisA rancher for over 50 years.
Carl
Bovines and most grazing animals face into the wind to graze. They also lay with their heads facing into the winds for their scent glands to pick up the smells in the airway.
Reply | Report Abuse | Link to thisA cattle rancher for over 45 years.
Let's see, if I face north, I won't have the sun in my eyes...
Reply | Report Abuse | Link to thisBack in the 1970s, a college professor in Illinois reportedly informed his Electrical Engineering students that cows in pastures with high-voltage transmission lines passing overhead tended to line up with the power lines' electric fields (maybe to minimize any tingling sensation if they cut across more field lines?). Maybe the electric-field and the magnetic-field sensitivities of cows (and other animals) are related? Seems likely.
Reply | Report Abuse | Link to thisMaybe, maybe not. There's a much more obvious cue to use to orient yourself north-south, and that's the sun. The researchers don't seem to have ruled this out. They say it doesn't seem to be sun-basking, but this may be the reverse - cows can suffer from heat stress on hot days, and aligning their bodies north-south in the mid-day sun would enable them to avoid having the sun strike them on their flanks. I also like MarkMark's idea that it keeps the sun out of their eyes.
Reply | Report Abuse | Link to thiscow's eyes are not in the front side i think
Reply | Report Abuse | Link to thisThis appears to be an example of worthless "research". 8,000 cows is not very many, and this is certainly not what I would consider as scientific. Looking at cows via Google is not a very exercise as well. What can you tell from overhead pictures? I raise cows and can say that mine certainly don't have a preference, although they do not like to eat with while they are facing downhill. Would you? Oops, maybe I ruined the study.
Reply | Report Abuse | Link to thisThey had to spend money on this? They could have asked any farmer and they could have told them that for free.
Reply | Report Abuse | Link to thisYou really gotta wonder...
Birds are said to be responsive to the earth’s magnetic field and such sensitivity helps to guide them in their long flights. But cow and deer? Could the habitual avoidance of the glaring rising and setting sun while grazing result in their North-South orientation? The outcome of this research does not appear to be conclusive.
Reply | Report Abuse | Link to thisSciAm seems to imply that there are specific places on earth like the coastal US where the direction of magnetic North pole deviates from geographic North. Isn’t the artificially fixed North always different from the fluctuating magnetic North all over the globe?
Please, read first the original article and then comment, discuss, criticize, or make suggestions
Reply | Report Abuse | Link to thisHynek Burda, a zoologist for over 35 years, and co-author of the paper under discussion
This only makes sense to me. Just like snails, whales and migratory birds, for example, the magnetic forces and other natural phenomenon such as sun and star positions are the most reliable guidance systems. However, the rifts that areoccurring in the magnetic field across the planet, especially in the southern hemisphere, may be the cause for disasters in these poor animals -- does this explain the whales beaching? Sandi
Reply | Report Abuse | Link to thisAs a cattle farmer, I agree with the rancher. My cows also tend to align into the wind, probably for exactly the reasons he gives (fly repellant and predator advance warming). If there's no breeze, they align randomly.
Reply | Report Abuse | Link to thisAs a PhD physicist, I respect data, and I'd like to see the data they used to conclude those cows align NS. Where is the original publication, and can we please see the raw data. How big are those error bars?
Dear Readers of Scientific American,
Reply | Report Abuse | Link to thisdo you really believe that a scientific journal like PNAS would accept for publication a paper, which has not been rigorously peer reviewed and where apparent alternative explanations were not considered? We are overwhelmed by reaction our article has released. We did not expect it, we do not understand it. Unfortunatelly, since most people read only second-hand reports in newspapers etc. and not the original paper, there are many misunderstandings. We do not manage to rectify them in all the blogs, forums etc. in the internet. Please read our more detailled reply in
http://www.nature.com/news/2008/080825/full/news.2008.1059.html
If you wish to read the original paper, just contact us - it should not be a problem to find the contact - we got already mails from several hundred people from all over the world.
Hynek Burda, Sabine Begall, Jaroslav Cerveny, Julia Neef, Oldrich Vojtech
I would suggest that similar studies of humans may draw the same conclusion. Think city street grids and how they may be aligned with the electromagnetic poles. Even Neolithic peoples knowledge, study and use of stars and sun position for their nomadic travel and aligning mounds, and structures. Our reliance on and use of maps and GPS, and our interest in our current location suggests we use every means at our disposal to align ourselves with the earths electromagnetic.
Reply | Report Abuse | Link to thisCurrently we as a species use many tools and aids such as writing, drawing, and electronic gizmos & but in the end a great deal of what we have done in the past and currently do may show that it was all to align where we are in relation to the earths electromagnetic field.