Dogs are sensitive to small variations of the Earth's magnetic field(frontiersinzoology.com) |
Dogs are sensitive to small variations of the Earth's magnetic field(frontiersinzoology.com) |
Alignment of the body (along the thoracic spine) in direction towards the head (heading) was measured in freely moving dogs (i.e., not on the leash) in “open field” (on meadows, fields, in the wood etc., i.e., unconstrained, and uninfluenced by linear structures, such as walls and fences) away from the road traffic, high voltage power lines, and conspicuous steel constructions during defecation and urination by a hand-held compass.
So it was not as simple as directional preference in sidewalks or roads.
The striking thing is that they only align N-S when the declination of the magnetic field is stable, but when the declination is changing they don't align. The differences in magnetic field direction is only a few degrees, so it's amazing that a dog whose head is flopping around can detect such small changes.
I don't know - for my taste, to exclude alignment to the sun they would have had to keep the dogs in a closed environment with an artificial light source. After all, even with clouds present you know where the sun is (and you can still get sunburned etc.)
It also rings my "skeptical" alarm bells when they cite the "original" evidence that cattle aligns along the N-S axis, but they don't cite the paper that fails to replicate the "original" findings in cattle: http://link.springer.com/article/10.1007%2Fs00359-011-0628-7
http://www.youtube.com/watch?v=D2SoGHFM18I&feature=youtu.be&...
Typically, the daily declination comprises westward-shifts 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.
Not that I know what calm vs stable MF would be. I wonder if it correlates with something else other than sun's position?
[0] https://en.wikipedia.org/wiki/Relative_direction#Cultures_no...
Why has this never been noticed previously?
Also, why have I never observed this behavior with my dogs?
And to the comedian who replied as well: dogshit and bullshit are not the same thing.
It also is unlikely that humans would be an exception here. However, my money still is on "Extraordinary claims require extraordinary evidence". Animals may be capable of magnetoception, but I don't think that has been proven yet.
For example, those foxes could try and minimize their shadows or changes in their shadows. They might do that using an internal clock. Alternatively, they might be able to perceive the polarization of the sky, and use that to guess where the sun is (note the high variation in successful angles)
Several mammalian species spontaneously align their body axis with respect to the Earth's magnetic field (MF) lines in diverse behavioral contexts.
You can read more at https://en.wikipedia.org/wiki/Magnetoception --- though, this is not without issues:
The largest issue affecting verification of an animal magnetic sense is that despite more than 40 years of work on magnetoception there has yet to be an identification of a sensory receptor.
I remember having read about this effect in homing pigeons, and the Wikipedia article also mentions that:
These results suggest that magnetite located in the beak of pigeons may be responsible for magnetoreception via trigeminal mediation. However, it has not been shown that the magnetite located in the beak of pigeons is capable of responding to a magnetic field with the Earth’s strength. Therefore the receptor responsible for magnetosensitivity in homing pigeons has not been cemented.
Without being an expert, it seems to me to be worthwhile research.