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.
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.
> 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.
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.
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.
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.