It is being widely reported as evidence that dogs orient to the magnetic field of the Earth when defecating (though apparently not when urinating).
The paper is full of complicated statistics and details about magnetic field fluctuations that are way beyond my mathematics and physics background. It is hard to think of a plausible reason why dogs would do this, though the authors take a stab at it. And they claim to “provide the first clear and simply measurable evidence for influence of geomagnetic field variations on mammal behavior. Furthermore, it is the first demonstration of the effect of the shift of declination, which has to our knowledge never been investigated before.” Quite an accomplishment, if true, but not surprisingly I’m a bit skeptical. Not any direct influence on vet med, but it would be both cool and weird if true.
I’m not going to waste my time reading the paper. My wife and I have four dogs in our household, and I can assure you they orient themselves randomly while defecating. It would take me less than one week to document enough defecation events to refute this idea.
I’ve heard the same thing about why dogs circle a few times before lying down. Where are the magnetic detectors in dog’s brains?
Its easy to laugh at a study like this but it important to remember that this is a controlled experiment so the results may differ from our everyday experiences where many other variables come into play. We also need to keep in mind that the purpose of the study is not to find out which direction dogs poop in but to try and find some evidence that they are able to sense the earths magnetic field. They just chose this way to study it because its easier to quantify this behavior than if they were to try to test a dogs navigation abilities and prove that their success was due to their ability to sense magnetic fields.
Brennan I have to admit I’m a bit lost with the discussion of axial and angular vectors etc.
I have 2 dogs, and I will just have to follow them outside for a while to see which directions they face to poop…and why is the poop more important than the pee, I mean if they orient themselves to poop, why not when they pee? Or eat? or, or…..
Macgyver, if dogs orient themselves to the Earth’s magnetic field they will need some mechanism to detect the field. I’ve looked into this in the past and no one has found such a mechanism. Couple that with the randomness dogs display when defecating and this study adds up to nothing.
As weird as the idea seems, I certainly don’t discount it out of hand. Birds have been shown unequivocally to have structures for detecting magnetic fields, which they use in guiding migration. It’s a bit of a question whether or not mammals can do the same thing, and this paper purports to show that they can. I agree that confirmation would require some plausible mechanism/anatomic structure to be identified, and I’m not aware of any at this point.
The question of why dogs would do this is the first issue that occurred to me. What possible selective advantage could it have? The authors suggest that the detection of magnetic fields is intended for other uses (navigation in a territory, for example), and the alignment during defecation is a way of “calibrating” the system regularly, but I don’t find that especially convincing. And as Asanta points out, why would they do it when defecating but not urinating? Still, unanswered questions don’t automatically invalidate a hypothesis.
The paper troubles me in that it contains a large number of measurements most of which do not show a significant pattern and a couple of which do. This is often a sign that the data has been dredged until a significant result is found, which is a red flag for spurious findings. However, I don’t understand the variables well enough to know if the comparisons made are reasonable. It seems the dogs oriented randomly under some conditions but appeared to orient non-randomly under others (having to do with the stability of the magnetic field at the time), but again I don’t know enough about magnetic field measurement to know if this is an appropriate way to parse the results.
What we need are a physicist and a statistician to help us poor biologists figure this out!
I suppose you could see if it really has any correlation with the magnetic field by putting a dog in a confined small yard and placing two strong electromagnets one at the east and the other at the west end of the yard with the opposite charges facing the yard and watch to see if the dog orients itself along those lines during defecation.
Macgyver, if dogs orient themselves to the Earth’s magnetic field they will need some mechanism to detect the field. I’ve looks into this in the past and no one has found such a mechanism. Couple that with the randomness dogs display when defecating and this study adds up to nothing.
I agree Darron and I am not saying this study or any one study proves anything. In fact Mckenzie brings up some significant concerns about the data. On the other hand I am not confident enough in our understanding of biology and neurophysiology to say that an animal can not detect magnetic fields simply because we have not yet identified a structure in their body that can do this. I also think its important to note that our every day observations are so fraught with bias and uncontrolled variables that they are not a great yardstick for questioning the validity of experimental results.
I have been observing multiple dogs defecate in my back yard for years. Their orientation is random. Do you want me to post photos of my dogs pooping? Give me a week and I can blow this paper into little bitty pieces.
For my next trick, I will prove horses do not sleep standing up, and cows do not eat all pointing the same direction.
Geez people. Get out of the city once in a while and learn how nature works.
I’ve had dogs all my life too and while I have never noticed any pattern either that does not mean there isn’t a greater tendency for them to orient in one direction or another. The study does not say dogs all orient with their noses pointing north. It basically says that there was not an equal probability that they would orient along any of the 360 degrees available. Their orientation tended to bunch up a little more often on one side of the compass than wold be expected by random chance. As I mentioned above, mckenzie pointed out a possible problem with this study. Its also just one study so it could have been a fluke or maybe there was a poodle in heat down the block and her scent caused them to all line up in one direction.
Since we’re on the subject of studies that sound silly, if you ever get a chance take a look at the Ig noble awards. They are given out every Sept to “honor achievements that first make people laugh, and then make them think.” The studies are interesting and the podcast of the presentations every year is actually very funny.
I’ve had dogs all my life too and while I have never noticed any pattern either that does not mean there isn’t a greater tendency for them to orient in one direction or another.
Our oldest dog orients herself parallel to the nearest fence. She also tries to hide behind trees. Yes, we have a modest dog. We used to have a dog that would turn 90 degrees to his left halfway through his defecation. One of our dogs will defecate, then walk about five to 10 feet, and finish defecating. He does not always face the same direction after he moves. Another of our dogs faces southeast or northwest when she defecates, depending upon which side of the porch she walked off. Our fourth dog goes out in the back yard and does his business without worrying about lining himself up with the Earth’s magnetic field. He’s just looking for a place out of the usual running path and not already occupied by a poop pile.
This study is not worthy of an Ig Nobel because it is not even ridiculous.
Edit: It’s official. My wife and I watched the dogs poop after breakfast. As noted previously, they all faced different directions.