Dogs poop in alignment with Earth’s magnetic field, study finds (2014) | Hacker News Reader

Dogs poop in alignment with Earth’s magnetic field, study finds (2014)

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346 pointspionerkotik160 comments

This study hinges on binning by variability of the magnetic field. It’s important to realize how small these variations are. The authors measure variation in the field direction in “percent”, but the units are arch minutes (1/60 of a degree in compass heading) per minute of time [0]. Calling this a percentage is kind of an odd pun on two meanings of the word “minute”.

According to the authors’ own interpretation, variation of 2 arch minutes of heading per minute of time is enough to destroy the claimed effect. In other words, they’re talking about a 0.03 degree change in direction in the amount of time it takes a dog to poop.

Perhaps you believe dogs are sensitive to magnetic fields, but can you really believe that they are also sensitive to such tiny relative variations in magnetic fields? Much more sensitive than a handheld compass?

I also agree with the general criticisms about p-hacking, but I think it’s worth having some sense of the actual size of the thing the authors are talking about, and how implausible it all is, apart from any details of the statistics.

[0] See figure 4 in https://frontiersinzoology.biomedcentral.com/track/pdf/10.11...

To make it even more concrete: realize that the hour hand on a clock moves 6 degrees per minute (it takes 60 minutes to go all the way around, 360 degrees).

This study claims that variations of the earth’s magnetic field direction that are more than 100 times slower than this have measurable effects on the behavior of dogs.

I think you meant the minute hand? The hour hand moves 0.5 degrees per minute. I also think your parent comment meant arc-minutes.

Yes, you’re right about the minute hand. Oops.

“arch minute” is a term used in the article, but “arc minute” also sounds more standard to me.

For a correspondence that makes more historical sense (while still not actually matching), you can assume that in one minute (of time), the sun travels 15 arcminutes across the sky. (21600 (arcminutes in 360 degrees) / 1440 (minutes in 24 hours) = 15)

I was initially confused about why they would divide up the data this way as well (being very puzzled why declination even came out as a bin, and that it meant what I thought it meant). Their measurement of the dog's orientation (or the dog's control of it) cannot even come close to this level of precision.

My suspicious side says that they saw that the overall data showed no strong correlations at all -- and then used variability in declination as a bin to get some result that shows some correlation. I have never heard of variability in declination (on this timescale) as a strong determinant of anything, much less micro sensitivity of a biological physiological phenomenon.

And yes, "arc" minutes is more standard.

I have four dogs, and I watch them poop every day. For some reason they have to slowly turn lots of circles before they're satisfied they have the best pooping position, and if the sun is out, they almost always settle on a position where they're not facing directly into the sun.

Makes sense from a practical viewpoint. You're more vulnerable to attack when you're pooping out in the open, and even moreso if the sun is right in your eyes.

To the extent that more pooping is done near the middle of the day, north-south pooping orientation would naturally dominate. No need for a sixth "compass" sense.

from the paper -- https://frontiersinzoology.biomedcentral.com/track/pdf/10.11...

Typically, the daily declination comprises westwardshifts in the morning and eastward-shifts in the afternoon, while the magnetic field is rather stable at night [21,22]. This calls for necessity to test whether the dog alignment is not actually influenced primarily by time of the day and most probably by position of the sun on the sky. We can, however, exclude this alternative. First, days when the magnetic field parameters change erratically and unpredictably (i.e., magnetic storms) are quite frequent. These changes have been well studied by others and are described in the literature (cf. [21,22] for reviews). Second, the data collection was not biased to either morning or afternoon (Table 8). Third, periods of sampling under conditions of quiet magnetic field were rather evenly distributed in the course of the day. Fourth, and most importantly, alignment during excreting was apparent under conditions of quiet magnet field, irrespective of the time of day or month. Time of day per se was not a reliable predictor of expression of alignment (Figure 2, Tables 3, 9). Fifth, generally, there are on average 1,450 sunshine hours per year at maximum in the Czech Republic and in Germany, on localities where measurements were done. Even if we would assume that these sunshine hours were evenly distributed over the daylight period and the year (as our observations were), there would only be a probability of 33% that the observation was made when the sun was visible. Hence, with high probability (67%) most walks during the daylight period were made when it was cloudy.

Last but not least, the argument that the dogs might orient with regard to sun position so that they turn with their back to the sun in order to avoid dazzling by sunshine during such a sensitive and vulnerable act as excretion can be questioned. This argument is not plausible for urine marking, which is a brief act. We doubt that a dog that cares of not being attacked would always make sure to be turned away from the sun. The dog will likely look in that direction from where danger can most probably be expected - and this is for sure not always the direction away from the sun. In contrast to a human, the dog is relying also on its nose and its ears (in some breeds even more than on its eyes) when monitoring its surroundings - so we may expect that the dog heads with its nose and pinnae against the wind or in the direction of interest. Directing the pinnae and the nose may take priority over eyes. One can also often observe that dogs (especially during defecation) align in a certain direction, which is actually a different one from the direction of interest and they turn their head then in that other direction. Also we have to take into account that dogs are smaller than humans, they look at a different angle over the horizon and even in situations when we are dazzled, they might be not. Quite important: note also that the preference is axial - there are many cases when the dog actually looks southwards. There is no evidence for shift of the alignment axis during the day.

that is.. a stretch. so they didnt actually look at sunlight hours they simply assumed the probability from the distribution of the data?? both hypotheses are plausible (sunlight vs magnetic fields) but this reads like data fitting rather than treating each possibility equally blind. where was it published?

Yes, I read the whole thing when it came out years ago. I remain thoroughly unconvinced. Back when this study came out, pop-sci magazines and websites reported it uncritically. But it was also a much less cynical time, before the reproducibility crisis really took hold.

Aside from the blatant and unapologetic p-hacking, there are some other flaws of data gathering and analysis that make their conclusions dubious. For example, note that your first paragraph above seems to admit that the actual presence of direct sunlight was not recorded in the raw data. They only figure in a statistical inference based on average hours of sun in a locale.

Rather than copy-pasting myself, here's a better critique from 2014 with good explanations of the study's problems:

http://skeptvet.com/Blog/2014/01/do-dogs-line-themselves-up-...

Maybe you should have started with that, rather than anecdotal evidence. I agree as a case study of potential p-hacking, it's pretty illustrative. Not sure if it's failed p-hacking though. For example -

High school students, but did make it into a journal ..

Dogs excreted with the body aligned along the North–South axis, but when exposed to small bar magnets, significantly changed their directional positions. The study suggests that dogs are able to recognize MF.

Additional value of this research is that the data were collected by local high school students, which required collaboration with teachers and their parents. We think that this idea has great potential and can be developed at a global scale and to become a citizen-science project involving other high school pupils and their families.

https://www.sciencedirect.com/science/article/abs/pii/S15587...

Dogs can be trained to find a bar magnet

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6301327/

We excluded visual cues and used control trials with food treats to test for the role of olfaction in finding the magnet. While 13 out of 16 dogs detected the magnet significantly above chance level (53–73% success rate), none of the dogs managed to do so in finding the food treat (23–40% success rate). In a replication of the experiment under strictly blinded conditions five out of six dogs detected the magnet above chance level (53–63% success rate). These experiments support the existence of a magnetic sense in domestic dogs. Whether the sense enables dogs to perceive MFs as weak as the Earth’s MF, if they use it for orientation, and by which mechanism the fields are perceived remain open questions.

So maybe there is some value in p-hacking, when taken with an appropriate grain of salt? The problem is science journalism and its readers often don't know how to do that.

> Maybe you should have started with that, rather than anecdotal evidence.

Oh dear. You mean I didn't approach this topic with the care it deserved?

> High school students...

Good for them! I only glanced at it, but it looks interesting.

> Dogs can be trained to find a bar magnet...

I read this. Right away, I can tell you the authors didn't take nearly enough care to eliminate the dogs' olfactory sense from the data, and the proof of that is that the dogs couldn't locate the jars containing food. Dogs should easily have been able perform that task, as anyone who operates a sniffer dog will confirm. The fact that these dogs couldn't do it means something is wrong, and I'd bet money that the problem was that the jars were handled in such a way that they all smelled of food.

To be fair, this would be quite hard to get right. Dogs have a sense of smell that can seem downright supernatural. When I was in high school, Denver PD had a bloodhound named Yogi who tracked down the body of a murdered child who had been transported ten miles by car. Yes, by car [1]. In training exercises, Yogi was able to track things that had been sunk thirty feet underwater at a local reservoir.

That craziness obviously presents an enormous challenge when designing a study on another hypothetical dog sense, and while this study went to some length to address it, something clearly slipped through the cracks such that the study's "food" arm (which was intended to serve as a control arm) was rendered useless. It also makes me strongly suspect that the magnets were also handled in such a way that there was some olfactory indication of which jars contained them. The paper doesn't tell us how the preparers handled the magnets and their containers, and there's no indication that they took measures to either prevent the transfer of any odor from the magnets to the jars, or somehow ensure that the odor was transferred equally to all jars.

My skepticism notwithstanding, I'm fascinated by the concept of magnetoreception in animals, especially birds, and I think it definitely deserves extensive study.

1 - Look up the Alie Berrelez murder case.

Police claimed that Yogi could smell whether a car carrying the victim had driven along the highway or down the exiat ramp, 4 days later. Supposedly the car exhaust blows your body cells out of the car and somehow into the ground but stays within a range of a few dozen feet. It doesn't pas the sniff test. Something else was going on, maybe a tip-off and the dog was cover for it.

https://unsolved.com/gallery/alie-berrelez/

> It doesn't pas the sniff test.

Was this pun intended? If so, well done!

I've heard some conspiracy theories in my time, but that's surely one of the lamest.

This was a search for a child who may still have been alive, and a suspect still at large. The cops were begging for tip-offs. Why in the fuck would they waste days or even hours with a fake search in order to "cover" for anything? Yogi worked out in the open, and he had an audience. Civilians were involved in the search, and in fact the body was actually found by a group of students who were assisting. People were able to watch the dog repeatedly lose the scent, backtrack, and pick it back up, working his way up into the canyon. That would be one hell of a dirty, dishonest performance by Yogi's handler, who by the way is still active in the K9 community.

Nobody knows exactly how Yogi did it, but given that dogs are to known smell at parts-per-trillion levels, and that there are many ways the killer's scent could be transferred to his own car tires, I don't think it requires an excess of credulity to take the police at their word.

That's an awful lot of unsubstantiated speculation. This has the vibe of a writer that has a foregone conclusion which they seek to reach.

This is also why dogs stare directly into your eyes as they poop. They're vulnerable, and you're their lookout.

Might also be why they come into the bathroom or wait by the door when you're doing your business.

That looks like a good explanation for all that monitoring borderline stalking going on in that specific room! I never thought of it, from now on I'll thank my dog for their service!

I’d ask for a source, but I choose for this to be true.

> Makes sense from a practical viewpoint. You're more vulnerable [..] and even moreso if the sun is right in your eyes.

"Dogs, like everyone, don't like the sun in their eyes." would be enough of an explanation for me. Predators even don't like the sun in their eyes, that's why they attack with sun behind them, if they can. Wouldn't make much sense for the dog to turn it's back in the most likely direction a predator is going to attack.

If predators attack with the sun behind them then shouldn’t dogs look into the sun to protect themselves?

Dogs look to their pack for protection while doing their business. If your dog stares at you while he's pooping, this is why. It's also why he might follow you into the bathroom... to keep you safe while you do your business.

But dogs are descended from wolves, which I think are apex predators, and were domesticated by humans, another apex predator.

Dogs are predators. We've domesticated a lot of that out of them, sure, but they've got the eyes facing forward and carnivore digestive tract. What would be higher to a wild dog or wolf in the wild?

Actually dogs & wolves have jaws and digestive tracts consistent with omnivores which are significantly longer than that of carnivores.

Correct. They can digest quite a bit of plant matter.

Cats, on the other hand, are carnivores.

I had a cat who liked tomato. It was weird.

Anything can be explained away depending on which variables you take into account.

Some people like heated toilet seats. Maybe most dogs like some warm sunhine on their behinds while pooping.

Or maybe they want to face upwind for other reasons.

> Predators even don't like the sun in their eyes, that's why they attack with sun behind them, if they can.

While I have no doubt that predators don't like having the sun in their eyes, they would obviously still prefer to attack with the sun behind them even if they didn't care. It's very advantageous, because the prey doesn't like having the sun in its eyes.

Attacking with the sun behind you is to prey with eyes what attacking from downwind is to prey with noses.

> north-south pooping orientation would naturally dominate. No need for a sixth "compass" sense.

What if it's both? Compass sense helps align them north/south for better vantage even when the clouds obscure the sun at the start of defecation/urination.

I skimmed the study and did not see anything regarding having controlled for day/night/cloud cover.

That's a hypothesis that can be checked. Go over the data and splice it by time of day, or rather position of the sun given the location/time/day of year. Then you should see a much higher correlation when the suns out than when pooping at night.

Sounds easy to test in the Southern Hemisphere. The sun being north rather than south is one of the things that threw me off when I first went to Australia.

Lots of pooping happens at night too, though...

> and if the sun is out, they almost always settle on a position where they're not facing directly into the sun.

The (linked) article says:

> (...) This calls for necessity to test whether the dog alignment is not actually influenced primarily by time of the day and most probably by position of the sun on the sky. We can, however, exclude this alternative. (...)

This has been discussed elsewhere in this thread. See my earlier comments for a rebuttal. Others like jwmerrill, dodobirdlord, MrEldritch, etc. have also made insightful remarks.

You don't need any magnetic field to distinguish the north-south direction. It is simply the direction shadows are cast when the sun is at its brightest. Consequently, plants will have adjusted to it, providing many (subconscious) clues. The sun makes things strongly non-isotropic, and these clues are everywhere; in the light, in the plants, in the wind, in sound, in urban planning, etc.

I expect most of the anecdotal 'evidence' to be explained by this. What would compel me is if randomly changing the magnetic field correlates with the observations, which is what this study seems to have done.

I encourage everyone to read the paper linked in the article. They've gone through surprising amounts of effort to justify their conclusion, and it includes some surprisingly nice graphs of the 'alignment during defecation' of dogs.

I sincerely hope their works will be recognised by the (Ig)-nobel committee.

The article was published at the end of 2013. They did get recognized.

Oh right, I hadn't seen the date. Glad they got recognised though.

They indeed won the 2014 Ignoble Biology prize!

https://www.improbable.com/ig-about/winners/#ig2014

I did not understand the 3 bins of 0%, 1%, 2% etc. declination. Does anyone have a simple explanation for that?

Also, the point about the sun is good -- maybe they just don't want sun in their eyes. Clearly the very dedicated and obsessed researcher needs to do a similar study but indoors. Can you imagine who has the personal passion to do this data collection?

I don't have a particularly good explanation for those specific choices, but I did notice that they resulted in somewhat similar sample sizes across all three bins, so it might just have been that.

Oh, I meant, I don't even understand what the bins are -- what is the declination measuring that they wanted to divide the data up by?

@jwmerrill wrote an excellent comment about this, which as of now is at the top of the thread.

hm. upon reading the paper, this is sounding very suspicious.

> The study was truly blind. Although the observers were acquainted with our previous studies on magnetic alignment in animals and could have consciously or unconsciously biased the results, no one, not even the coordinators of the study, hypothesized that expression of alignment could have been affected by the geomagnetic situation, and particularly by such subtle changes of the magnetic declination. The idea leading to the discovery of the correlation emerged after sampling was closed and the first statistical analyses (with rather negative results, cf.Figure 1) had been performed.

Like, am I reading this wrong, or are they straight-up saying "we couldn't achieve statistical significance on our original hypothesis, so we just went fishing for correlations until one of them came up significant, and it turned out to be magnetic declination"?

Yes, that's a straight up admission of p-hacking.

Also, the weasel word "truly" signifies deceit.

I don't think that's necessarily a bad thing, though my opinion might've been influenced somewhat by 538.

https://fivethirtyeight.com/features/science-isnt-broken/

Why not? Science that insists on hypotheses written down beforehand is cargo-cult science. Observation is the first and most productive science. Double-blind experiments are to cement gains.

You are confusing hypothesis generation with hypothesis testing. Both are science, but only one is a reliable way to determine truth.

Probable claims. Not truth.

In the non-Platonic real world, truth is claims that we believe have high probability.

Not if you want to claim statistical significance. The math behind this method is based on defining the hypothesis before seeing the data (and even then it's usually very weak evidence of a tiny signal within the noise).

basically, because once you start trying multiple hypotheses on the same dataset, the math used to determine "is this conclusion real, or am I just fooling myself" begins to break down.

The statistical significance threshold usually used is p<0.05, meaning that something is (generally, this is beginning to change since the replication crisis) considered to be a real discovery if it has less than a 1/20 chance of being a false positive under the chosen model.

As soon as you start trying multiple hypotheses, then that 1/20 chance of being a false positive begins to become meaningless. If you can just keep rolling d20s until one of them comes up with a critical hit, then you can easily generate false positives that still look very robust.

This is exactly the sort of bad science - p-hacking, fishing expeditions, and the garden of forking paths - that led to the replication crisis. (And that makes sense, as this paper is from 2013, and predates the widespread discovery of the crisis)

Thanks! For someone that didn't understand why this was considered p-hacking, that made a whole lot of sense.

p<0.05 is also cargo-cult science, and is much more responsible for the replication crisis -- along with biased sampling (pop. 18-22 yo US psych students).

It is also why we see repeated, spurious insistence that anti-depressants don't do anything.

Experiment design is a subtle skill.

The math continues to work out as long as you use the right approach. You have to collect twice as much data, and then set half of it aside at random without examining it. Then you can do whatever perverse p-hacking multi-modeling curve-fitting whatever to the half you kept until you reach a hypothesis, then check it against the half you set aside to recover the statistical significance you lost by using techniques that may have overfit the first half. Unsurprisingly, the math works out because this approach is isomorphic to collecting the first half, studying it to form a hypothesis, then conducting a proper pre-hypothesized experiment to collect the second half. Validation via holdout sets is the same approach used in machine learning and elsewhere to prevent models from overfitting data.

This is true! I was trying to simplify things a bit for a basic explanation, but I fear I oversimplified. I just meant that the generally used math breaks down; if you're aware of the problem, you can correct for it, but very often people don't.

Stating it more plainly, what you wrote was incorrect, and unfairly tarred a statement that was, in fact, correct.

No. If you collect data and then hunt for "significant" results in it you are guaranteed to find spurious results. This is one of the most basic truths of statistics.

xkcd explains it better than I can. Basically if you pick p values that give 95% certainty 20 times you're probably going to "discover" at least one falsehood.

https://xkcd.com/882/

You seem to be under the impression that a study like this gives a hard "yes/no" answer as to whether some hypothesis is true. That is not the case, nor is it ever the case with most studies like these. Instead, you need to do some sort of statistical hypothesis test.

As other comments have pointed out, once you start testing multiple hypothesis on the same dataset, you cannot apply the same significance threshold that you would if you had just begun with a single hypothesis before observing the data. Instead, you need to apply some sort of correction that takes into account the number of hypothesis being tested:

https://en.wikipedia.org/wiki/Family-wise_error_rate#Control...

Well, it would be p-hacking if you tried 1,032 different hypotheses until you got one that passed your threshold. There's quite a lot of scientific history (e.g. Kepler's discovery that planets went in elliptical orbits) that would have to be thrown out if you decided you could never use data for anything other than the original hypothesis. Kepler didn't even collect the data, much less collect it with the idea that the planetary orbits were elliptical.

Having said that, the results smells (pun intended) bad, just because I cannot think of any plausible reason for a non-migrating animal to align with the magnetic field, when defecating or at any other time.

This is true, and a valid point. The way they phrased it does make me feel more than a little suspicious, nonetheless.

(Besides, there's some other oddity there, like that apparently the alignment only matters when the magnetic field is calm)

When the magnetic field is non-calm that is probably due to a space weather event that is geo-effective and inducing large currents in the ground. The local magnetic field an then be significantly distorted depending on local conductivity. So to me that is not an oddity.

You're right to still feel suspicious. Who's to say they didn't try 1,000 different post-hoc ideas? They declare only one, the may have been others. I'd be looking for preceding research and any published protocols, if I wasn't on mobile and didn't think it would be fruitless.

I mean, humans can detect magnetic fields as well. There's even languages without relative egocentric positions like left/right, only north south east west. Given all that, I don't think it's out there that dogs sense it and like being aligned when they're trying to poop.

https://www.sciencemag.org/news/2019/03/humans-other-animals...

https://en.wikipedia.org/wiki/Guugu_Yimithirr_language

The predominance of geographic directions in Guugu Yimithirr has nothing to do with magnetic sensing; humans know what north and south are from sun positions and memory.

> any plausible reason for a non-migrating animal to align with the magnetic field, when defecating or at any other time.

Snow foxes seem to hunt better when oriented in direction of the magnetic north.

https://m.phys.org/news/2011-01-predation-foxes-aided-earth-... https://youtu.be/D2SoGHFM18I

> any plausible reason for a non-migrating animal to align with the magnetic field, when defecating or at any other time.

I got my dog a few years back when she was just a pup. Over the years, she's done things that she was never taught how to do (swim, hunt, bury her food), she just new how to do them instinctually. I believe something like this falls under that category.

And for the record, she took a crap this morning and was pointing directly north/south.

> "The study was truly blind."

I'd argue the study would only be truly blind if the dogs were blind. If blind dogs also oriented themselves north-south, then that would prove that they weren't using visual cues for alignment, such as the position of the sun.

You can feel the heat of the sun

P-hacking only apply to proofs. This study does two things, it falsifies a previous hypothesis fair and square, with no p-hacking, and it postulates another hypothesis, an activity where the concept of p-hacking does not even apply.

The only wrong party here is the one that reported the study found something.

The sun set/rises East/West. Maybe dogs just don't like looking directly into the sun when they go.

That was my first thought too.

Pages 6-8 (5-7 pdf) discuss the sun as well as measurements across times of day.

https://frontiersinzoology.biomedcentral.com/track/pdf/10.11...

What about pooping at night though?

Or high-noon? I have it on good suspicion that dogs can poop any time of day, not just early morning/evening.

This is fun, however it seems like it would be easier and more reliable to just put some dogs next to a gigantic magnet. There are a number of confounds related to sunlight and other geophysical parameters (wind) that are not controlled for in this study. A magnet would demonstrate a clear causal link much faster than forcing some grad students to watch dogs pooping in uncontrolled settings. Though I suppose people who own 4T magnets are probably not cool with some random person showing up with a dozen dogs and a couple of compost bags.

That's the next paper I'm sure. This one was likely a study of the results and an accidental reveal of the correlation. It's possible the correlation was accidental though, a minor bit of p-hacking.

It'd be awesome to prove this false (if false) as it'd be a very compelling learning study for problem of p-hacking.

It's turtles all the way down

http://scienceinpoland.pap.pl/en/news/news%2C80222%2Cwoof-yo...

Should humans be doing the same? Is the failure to align toilets contributing to increased stress? We need more research!

Pitch to Gwyneth Paltrow: Pooping magnets.

Dogs get feng shui.

...I used to joke with my wife this must be the case.

My dog spends so much time trying to find the right place. It’s during the day, so it can’t be astrology, so must be leylines or the magnetic field of the earth. Elementary really

She will get a kick out of this article for sure

If it were magnetism, it would be pretty easy for the dog to choose the direction.

The thing I love about this story is that it is SUCH a dog thing to do. Dogs would absolutely poop in alignment with earth's magnetic field. They wouldn't need a reason to do it. It's just the kind of thing they'd do.

Related: in 2008 the German University of Duisburg-Essen did a study on cattle based off of Google Earth images, with similar results.

The researchers also did field studies of deer in the Czech Republic. They found that the vast majority (well over 2/3) aligned themselves along a north/south or south/north meridian [1].

edit: it seems tomas_aspre found the actual publication [2].

[1] http://news.bbc.co.uk/2/hi/science/nature/7575459.stm

[2] https://www.ncbi.nlm.nih.gov/pubmed/23700176

Turn it into an experiment and I'll believe it. See if you can control where dogs poop with an elecromagnet.

It is interesting. Now that it was pointed out, the pattern does seem to match our dog as well. I would love to find out more.

Mamy who saw dog select a spot are aware of the 'thrice blessed' dance.

I'm kind of skeptical on this one.

I find that there are far more factors that tend to take priority in the direction our dog relieves herself. Oncoming/prevailing wind, rain, whether she was spooked in a particular direction or not, amount of exertion (was she running or walking before the urge hit), ambient noise, presence of echo, presence of other animals and whether or not she feels safe around them.

I mean, it's a nice sample size, and I suppose the data is fun, but a follow up should probably be done taking into account magnetic north is currently hauling ass to the geospatial west and see if dog alignment changes with that.

Furthermore, where are the instances of dogs forming defecation circles around MRI's?

No defecate based outlines of magnetic field lines, no dice in my humble opinion. Yes. I know, I'm a stick in the mud; but if you're going to claim something like this, that's actually a fairly easy way to confirm it. Just head to a radiology clinic with your dog and have them do their business. You should see wildly divergent behavior over time, because they aim to keep those machines operating regularly, which should definitely be able to overwhelm the Earth's ambient magnetic field in close proximity.

I come to HN for the comments. You don't disappoint. I'm glad we have multiple people whom thinking critically enough about a publication to demystify it.

Nate says it's simply primal. Eldritch talked about the cognitive bias. Etc, etc. thanks for the critical thinking!! keep up the great work!

Surprised to see this on pbs (then again, not) but a great example of anti-science being buoyed by a sea of epistemic uncertainty. Hopefully we'll being hearing more about this study come September at the Ig-Nobel awards, in the category of best p-hacking.

*pee-hacking

I don't have dogs, but I see people walking their dogs, and they don't give a damn which way they're facing. Tree, bush, wall, open pavement - all fine. They walk, they break, they walk.

My dog is obviously not a compass. This study is more about showcasing bad research methods than anything else. (Especially if it's unintentional.) I'm reminded of the famous dead salmon fMRI result: https://www.discovermagazine.com/mind/fmri-gets-slap-in-the-...

Instant Ig Nobel finalist.

https://www.improbable.com/ig-about/

I wonder how the researchers came up with the idea to study this.

Anyway, this is good news? Dogs are more similar to humans, than what birds are, right. Maybe there's a magnetic field sensing dog gene that can be copied to humans? So that at least the future generations won't lose their orientation, as fast as I do, in the streets and indoor shopping malls.

There is a human neural response to magnetic fields: https://www.sciencedaily.com/releases/2019/03/190318132646.h...

> revealed a decrease in alpha-band brain activity -- an established response to sensory input -- in some participants

Interesting this happened in only some participants.

Makes me wonder about sensing fields caused by electricity or the very weak fields caused by flowing water (which tends to contain some salt ions / charged particles).

Edit: flowing water = no fields, because plus and minus ions evens out, no net charge. However if one is small as a molecule and really close to the water, then I suppose one would feel the fields of individual dissolved salt ions passing by

They were fishing for anything of apparent statistical significance.

Likely because this is common behavior in animals and humans. It makes sense that dogs could be influenced.

> this is common behavior

What does "this" here refer to? (Thanks for the reply :- ))

This reminded me of this article in the BBC of

https://www.bbc.co.uk/news/av/stories-51281856/electrosensit...

and related studies behind it

http://www.utdallas.edu/news/2016/2/3-31891_Study-Uncovers-H...

https://www.theguardian.com/science/2019/mar/18/humans-earth...

Basicaly in nearly all Hindu texts, when praying or doing Yoga they tell people to face East/the sun, so that your magnetic field is aligned as unaligning it risks disease.

The team say modern environments would likely interfere with this “sense”, while there is no sign as yet that such a system is linked to human consciousness, or that it influences our behaviour – although the team say it remains a possibility, and are planning experiments to find out.

I wonder if dogs almost feel a need to align with field in the right way to feel comfortable.

I’m a real skeptic on this. I’ve had dogs my whole life and they just shit any which way they want.

There have been no follow up studies that I can find to replicate this “experiment”.

Searching around just finds lots of duplicate stories in the old echo chamber based on the original paper.

https://frontiersinzoology.biomedcentral.com/track/pdf/10.11...

The dataset seems to be robust. Would be even more interesting if reproduced, but I'd be surprised if someone faked nearly 7500 datapoints for the sake of giving dogs a magnetic sense.

Same. Reminds me of the study on stork vs human baby births. That was proven wrong shortly thereafter.

Do they though? Take a compass out with you next time.

Mine almost always face mostly north or mostly south, now that I'm thinking about it.

And I'm pretty sure the dogs out my apartment window face mostly N/S. Will observe. There's a busy road right there so they might face it some

I think it depends on the dog. Mine circles several times until she has found the perfect spot. Some fosters we had would just throw down wherever. I’ll definitely watch the direction next time.

When I saw this, my first thought was that circling could allow magnetic alignment.

They do the same before lying down. It's never been understood exactly why that is.

The reason I've read is that it's a leftover from when they lived in the wild, and it would help make sure they don't lay down on top of something dangerous, like a snake or ant colony. It would also make since to do it before pooping since they're going to be in a vulnerable position.

Would be nice to know if there is any other reason, other than “don’t like sun in my eyes”.

I remember during the tsunamis, animals knew something is gonna happen and got restless. I wonder how much of these intuition and senses humans have lost, by tuning out nature

Anecdotally, I actually tested this one time. I pulled out my phone and launched the compass app. My dog was PERFECTLY aligned and was facing north while pooping. Never tested it again, tho. But if it was a fluke, it was a very impressive one.

My wife, who can barely read a map, has such good directional sense that I am convinced that attoampere(?) currents induced in her brain as she cuts through the earth’s magnetic field are interpretable by her and form memories.

What are the applications if we would breed dogs based on that "skill"?

We could breed homing dogs that can find their way home by following the treasure trail they left behind.

Well they have a good sense of smell already so the magnetic aspect probably wouldn’t add much.

Instead of packing a heavy compass when you go hiking, just bring a dog!

Hope this gains traction - imagine the societal consequences of optimizing human magnetic alignment in city planning and building/room layout.

Also interesting and relevant:

Magnetic alignment contributes to difficulty falling asleep (north-south alignment is best) [https://www.researchgate.net/publication/280093617_The_Relat...]

Grazing cattle align on north-south axis [https://www.ncbi.nlm.nih.gov/pubmed/23700176]

Is it just me or is it really weird to start a scientific paper with "sleep has been one of God’s most precious blessings since human’s existence and it is vital for both body and soul"?

It reminds me of a line in "The Rime of the Ancient Mariner":

https://www.litscape.com/author/Samuel_Taylor_Coleridge/The_...

I'm extremely skeptical of the study you linked about magnetic alignment and sleep latency.

Just looking at table 6 (the only table related to the only association stated significant), the stats for South-North sleepers look noticeably better than the stats for North-South sleepers. I'm no statistician, but just look at it. The South-North sleepers sample, versus the North-South (supposedly best) sleepers, has proportionately three times more people experiencing zero days weekly of difficulty getting to sleep, two-thirds as many people having even one day of difficulty, two-thirds as many people having two days of difficulty... and 50% more people having three days of difficulty, but even then, we're talking only four people each among a group of 47 vs a group of 35. Again, I'm no statistician, but does that last and smallest column overshadow the three much bigger columns with the opposite trend, to the point of being a 1 in 1000 result assuming the null hypothesis?

Furthermore, the sleep measures were self-reported, through the Pittsburgh Sleep Quality Inventory (PSQI), which I quote:

>In Iran, Tehran psychiatry institute assessed the validity and reliability of the Farsi version of this questionnaire with 89.6% for sensitivity and 86.5% for specificity.

Did the math behind this eye-catching <0.001 p-value take into account that the questionnaire used was measured to have a 10.4% false negative rate and a 13.5% false positive rate? I find it hard to believe. But I'd love to see a statistician who actually knows how to interpret these numbers tell me that I'm wrong.

This is an American study and a lot of cities in the USA have a street grid with the orientation North - South. It could be dogs orientate position on the wind axis.

I just want to say that these are some of the most fun comments I've seen in a while on an HN thread. Thanks everyone and make sure your toilets are aligned!

Now that you mention it, my childhood dog almost always faced mostly north or south when conducting her business

Is this why some folks think dogs seem to be able to predict earthquakes? They have some built-in connection?

Earthquake build-up produces electric fields.

It would be a different sensory system.

To be fair, this is pretty common in animals. https://www.momtastic.com/webecoist/2008/09/18/animal-magnet...

It's quite possible.

My partner after me speaking about this, with zero irony: “I think that study is a load of shit”

Dogs circling to poop, puts a new spin on the idea of the lodestone.

Did they have a control group pooping inside a Faraday cage?

Fun fact: Faraday cages don't block low frequency magnetic fields. But mu metal and active magnetic shielding can :)

God damnit, that made me laugh. Beautiful creatures.

I'm so glad somebody is finally looking into this

Tax dollars well spent!

Czech tax dollars to be accurate.

The study was supported by the Grant Agency of the Czech Republic (project. nr. 506/11/2121)

"Duckspeak" was the term from Orwell's 1984 for babbling slogans as a sort of automatic pattern matching response to stimuli.

I think the authors need a reminder that coprology does not imply causation.

I just grabbed my compass to check...can confirm that my black lab Piper's recent poops have been north/south. Now that I think of it, I can't remember a time she hasn't been facing north/south...no matter the weather or time of day.

I simply don't believe this study. And this stuff is important, how animals including us interact with the magnetic field is not a small thing. 6 years later it needs backing.

Anyway if you too want to interact with Earth’s magnetic field in a stronger way you can augment like this -

"For six weird weeks in the fall of 2004, Udo Wächter had an unerring sense of direction. Every morning after he got out of the shower, Wächter, a sysadmin at the University of Osnabrück in Germany, put on a wide beige belt lined with 13 vibrating pads"

https://www.wired.com/2007/04/esp/

I'd like to hear an impartial experience on this, it seems interesting but like putting magnets in your fingers after all that effort people tend to exaggerate the experience. I think a Kickstarter was tried around it.

Considering all the cases that were excluded, and the imprecision inherent in measuring poop direction, N is pretty low here.

2013/2014

You could answer this research question much more accurately by building an app and collecting data from users mobile devices.

LOVE weekend posts on HN!

Tax dollars.

Twelve authors on a paper about dog poop.

And people wonder why academia isn't taken seriously by normal people...

Or maybe, dogs just don’t like to look straight into the sun when they poop, which rises in the east and sets in the west. Good grief. Sometimes the smartest people are also the dumbest. Would you stare right at the sun when pooping?

They tested for that:

> The fact that larger and faster changes in magnetic conditions result in random distribution of body directions, i.e., a lowering of the preferences and ceasing of the avoidances, can be explained either through disturbing or conscious “shutdown” of the magneto-reception mechanism.

I’ll bet if you repeated the whole thing on cloudy days only the effect would go away. You’d have to have very very strong evidence that dogs have some sensory organ that detects magnetic fields when the sun is right there in the sky and explains the effect in a way that is obvious to everyone.

> I’ll bet if you repeated the whole thing on cloudy days only the effect would go away. You’d have to have very very strong evidence that dogs have some sensory organ that detects magnetic fields when the sun is right there in the sky and explains the effect in a way that is obvious to everyone.

again, pages 5-6:

> Even if we would assume that these sunshine hours were evenly distributed over the daylight period and the year (as our observations were),there would only be a probability of 33% that the observation was made when the sun was visible. Hence,with high probability (67%) most walks during the day-light period were made when it was cloudy.

There's wisdom in reading the study before commenting further considering your specific rebuttals have all been addressed in the source material. There were literally nearly 7,500 measurement events factored into this study, the majority of which were likely cloudy given the location.

Likely? so let me get this straight, they didn’t even record which days were sunny? Extraordinary claims and all that. Sorry but I’m right about this no matter how many downvotes I get.

> Likely? so let me get this straight, they didn’t even record which days were sunny? Extraordinary claims and all that. Sorry but I’m right about this no matter how many downvotes I get.

Please just read the paper. Events were timestamped, aggregated over two years, and took place at all times of day (including well after dark) with the same outcome.

Disengaging. Cheers, friend.

Voting is often influenced by tone and adherence to site guidelines, not just accuracy.

They only find the effect for cases where there is low flux in the magnetic field.

This indicates another reason to be skeptical of the study. If an effect is found in one condition and not another this is a red flag for p-hacking.

High flux means the direction of the field is undefined.

"High" flux for geomagnetic fields means it changed by a few degrees. So it's not anywhere near undefined, just slightly off.

> Or maybe, dogs just don’t like to look straight into the sun when they poop, which rises in the east and sets in the west. Good grief. Sometimes the smartest people are also the dumbest. Would you stare right at the sun when pooping?

Pages 6-7 (pdf pages 5-6, or just grep 'sun') of the source study (https://frontiersinzoology.biomedcentral.com/track/pdf/10.11...):

> This calls for necessity to test whether the dog alignment is not actually influenced primarily by time of the day and most probably by position of the sun on the sky. We can, however, exclude this alternative. First, days when the magnetic field parameters change erratically and unpredictably (i.e., magnetic storms) are quite frequent. These changes have been well studied by others and are described in the literature (cf. [21,22] for re-views). Second, the data collection was not biased to either morning or afternoon (Table 8). Third, periods of sampling under conditions of quiet magnetic field were rather evenly distributed in the course of the day.Fourth, and most importantly, alignment during excreting was apparent under conditions of quiet magnet field,irrespective of the time of day or month. Time of day per se was not a reliable predictor of expression of alignment (Figure 2, Tables 3, 9). Fifth, generally, there are on average 1,450 sunshine hours per year at maximum in the Czech Republic and in Germany, on localities where measurements were done. Even if we would assume that these sunshine hours were evenly distributed over the daylight period and the year (as our observations were),there would only be a probability of 33% that the observation was made when the sun was visible. Hence,with high probability (67%) most walks during the day-light period were made when it was cloudy.

> Last but not least, the argument that the dogs might orient with regard to sun position so that they turn with their back to the sun in order to avoid dazzling by sunshine during such a sensitive and vulnerable act as excretion can be questioned. This argument is not plausible for urine marking, which is a brief act. We doubt that a dog that cares of not being attacked would always make sure to be turned away from the sun. The dog will likely look in that direction from where danger can most probably be expected - and this is for sure not always the direction away from the sun. In contrast to a human, the dog is relying also on its nose and its ears (in some breeds even more than on its eyes) when monitoring its surroundings - so we may expect that the dog heads with its nose and pinnae against the wind or in the direction of interest. Directing the pinnae and the nose may take priority over eyes. One can also often observe that dogs (especially during defecation) align in a certain direction, which is actually a different one from the direction of interest and they turn their head then in that other direction. Also we have to take into account that dogs are smaller than humans, they look at a different angle over the horizon and even in situations when we are dazzled, they might be not. Quite important: note also that the preference is axial - there are many cases when the dog actually looks southwards. There is no evidence for shift of the alignment axis during the day.

---

Shoot, they even have pitch-dark measurements on page 8 (pg 7 pdf)

I’m right about this and all you guys are someday if you remember it going to regard this as tremendously embarrassing.. I mean you all just immediately believed the most far fetched of hypotheses based on one flawed study in which they didn’t record which days were sunny.. signing off

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