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Birds can see Earth's magnetic fields because of cryptochromes in their eyes (sciencealert.com)
403 points by startupflix 10 months ago | hide | past | web | favorite | 120 comments

I'm not sure why, but the few times in high-school that I took acid, I could see lines in the night sky going north to south. It was deterministic, like clock work.

Does anybody have an ideas why? I mean, I wasn't really hallucinating, I didn't take too much. I could always truely find north or south. I couldn't tell what was north or south, but I could draw the line, always.

Am I crazy? I mean, I'm not saying I'm a bird, but...

I too have experienced such "deterministic" hallucinations. This has fascinated me for some time.

One theory is that the phenomenon is always there but that that visual layer is tuned out, just how with practice you can tune into many visual layers: you can learn to see floaters, the white blood cells moving through the capillaries in your retina, your own heartbeat, noise in the image, etc.

It may serve some function yet to be discovered. At the very least, it is beautiful.

I can easily see my heartbeat in my vision by staying still and concentrating. Everything shifts slightly with each pulse, you just don't notice because the overwhelming vibrations contributed by ordinary life interfere with the weak signal of the heartbeat. But how can you train yourself to see white blood cells? What do you look for?

What a sweet simulation. Thanks for the link!

Some people affected by eye Toxoplasmosis begin to see floaters all the time. And, strangely, it make at least one person on Earth also see those white blood cells (the little white spots you see against a blue, bright sky) with the unaffected eye, too.

Interestingly, I read a while back about polarized light being visible to a portion of the naked eye.


I found that I was able to see Haidinger's brush infrequently. One experiment (which I sadly cannot remember a citation for) suggested that lines in the sky would point north/south.


Also, I forgot to mention that the lines would curve around the light of large stars. It was almost like the oval notches/holes in wood grain. Only the large/visible stars did this.

Even if you could see magnetic fields, it wouldn't look like lines in the sky running north to south, so this does sound like an hallucination.

So what would a magnetic field look like (to the naked eye, not just a visualisation of field lines with iron filings or similar) if you could see it?

Well, I imagine the crystals can only perceive single vector values of the magnetic field at the position of the eye. Imagine each censor returning a vector defining the magnetic field at a point on the eye. There probably wouldn't be any way to focus or change depth of perception like one could with light. You'd have to move your eyes through space to get more than a localized snapshot.

But, you can probably predict what a magnetic field looks like away from the point of measurement, I.e. the eye. What is fascinating to me is that they could potentially be learning to deal with manmade magnetic fields, adapting to human culture in a possibly novel way.

Most likely it would seem as if the air is distorted by some diffuse gas other than the air contains. If you vent a nitrogen gas bottle you'll see a shadow that the gas escapes, but you cannot see it with the naked eye. So, for seeing magnetic fields you'll need also to see some specific electromagnetic wavelength which would shift in the presence of a magnetic field (much like light scatters when gases move). With complex neural networks involved in an eye it's likely that those specific light receptors found make it possible to perceive magnetic fields penetrated by sunlight. Which is basically shown in the pictures.

There are pictures in the article.

How do you explain that they were always from north-to-south? I mean, I tried hard to trick myself even. An actual hallucination couldn't know.

Knowing which way is north and south is different from being able to visually see it. It's likely that you knew which way is north and south without realising it. Even if you were very good at tricking yourself, you may have got it right just by chance.

I seem to have a very good intuitive sense of direction. When I lived in Ottawa, though, I used to always get lost when I hit the river. It took me years to figure out what the problem was. The river runs roughly east west and so all the signs say "East" or "West", but it's actually in the shape of a V. Most of the time it's running NW/SE or NE/SW. Every time I hit the river, I'd consciously think that I'm going East/West when in reality I was going in a completely different direction. It really threw me off.

I think people are more attuned to direction than they think. Direction of the sun, time of day, landmarks, direction of shadows, position of moss on trees, etc, etc. After years and years of seeing it, your brain get's pretty good at orienting you -- even if you don't consciously understand it. These days, I try not to reason about my orientation, but rather guess. I tend to have better results.

I don't think I have to explain (though the first explanation that comes to mind is that you were familiar enough with the location to have a pretty good idea of approximately which direction you were facing).

The point is that magnetic field lines are a convenient diagrammatic tool, but don't have a direct correspondence to any physical reality. It's just like the way we sometimes draw electromagnetic radiation as a sine wave, but try as you might you won't ever observe little squiggly sine waves in physical reality.

> The point is that magnetic field lines are a convenient diagrammatic tool, but don't have a direct correspondence to any physical reality.

Magnetic field lines correspond as much to physical reality as anything possibly can. https://physics.stackexchange.com/a/80913

Also here's a trippy video: https://www.youtube.com/watch?v=rUZsojDdEbE

There's a vector field, but it's continuous - you can't point to two points in space and say "a field line passes through this one, but not this one".

You can point to points in space and say that the scalar value of their vector field is the same or different, and say whether or not there is a continuous path of scalar value sameness between them.

Iron filings do a pretty good job of showing us "lines" in physical reality.

The iron filings actually concentrate the field, which leads to a bit of an avalanche effect as the concentrated field attracts more filings towards it that creates the lines.

Those lines are entirely conceptual.

If you see these lines in the iron filings, they are perceived, i.e. perceptual-level evidence not conceptual.

Well, you could repeat the experience and arrange for a double-blind trial or something. :)

" I could see lines in the night sky going north to south. It was deterministic, like clock work."

Even though I am open to alternative explanations, I would say it is also possible, that your knowledge of where north and south is - and your knowledge about the magnetic field - might be enough as an rational explanation.

So to prove - you would need to be able to do the same in an enviroment, where you do not know the directions ...

Weak condensation trails that you didn't bother looking for sober? Aircraft often follow deterministic paths.

LSD or any psychedelic, can make the user more sensitive the energies that we normally cannot sense. Non-humans seem more sensitive to these energies than we are, whether because their stronger senses allow them to notice what we cannot, or whether they have better intuition than we do, because they're not taught to subconsciously disregard it as fantasy, delusion or coincidence, etc.

LSD + "Energy perception" = Free Energy Movement wavies.

Can you please give a link to a peer reviewed article about these energies?

grep "power line"

...am I really the only one who thought about whether this might contribute to why power lines are so attractive for birds to perch on?

It's likely that they might see the power lines' magnetic "signature" before everything else, as if the lines are highlighted or marked by a visual filter. Large congregations of birds on power lines preparing for a flight, however, is not a clear indicator for that. Perhaps power lines are just more convenient than searching for a tree large enough for the whole flock.

I'd think a more plausible explanation would be that birds prefer a location difficult for predators to reach undetected, and which has a wide field of view. I think it's also presumptuous to assume that just because an organism can see something better, means they prefer it. E.g. There's no doubt that humans can see bright flashing multi-colored lights better than sunlight on an overcast day, but I don't think anyone would argue that humans would prefer the blinking lights over the natural ones.

I suspect the magnetic field around a power line is thousands of times more powerful than earth's magnetic field.

It would likely overload the birds senses and not be a pleasant experience.

Their perception could be non linear, much like our perception of light intensity. Or it might be adjusted automatically to a higher value, dimming the earth's field but making power lines "bright" but not blinding.

What a cool possibility overall!

There’s a difference with power lines because it runs an AC current. The earths magnetic field is static for all intents and purposes.

I wonder if they would perceive unnatural magnetic fields, particularly small, strong fields as something strange enough to avoid?

If so, I wonder if one could discourage birds from hitting windows by arranging for a strong magnetic field outside the window?

There are ways to discourage birds from flying into windows, but they often make the window less useful to humans.

There have been experiments showing that attaching magnets to birds' beaks inferfere's with their ability to sense magnetic north. So yes, they can "perceive" any magnetic field, but since their main use for magnetic fields is finding north, any other field is likely going to confuse and disorient them (similar to how artificial lights confuse moths that mistake them for moonlight), making them more likely to crash into objects, not less.

Well, maybe some do, but surely not all. Transmission lines do have some strong magnetic fields around them and birds don't seem to care much.

Or keep them away from airports.

Eagles are very good avoiding planes and working as airport security buddies.

This raises some interesting questions for me.

First since I've been doing some Software radio stuff of late, I'm wondering if there is a way to build a chemical detector for magnetic fields that would allow one to pick up signals without a giant magnetic loop antenna. The paper (linked in another comment) suggests that the frequency response is low (1uS to 100uS) so it would not be a high bandwidth link :-).

The other is what happens when the poles swap?[1] Do the birds commit mass suicide as they fly north for the winter and south for the summer?

[1] https://www.extremetech.com/extreme/192522-earths-magnetic-f...

I think the nitrogen-vacancy center in diamond might fit your bill.

Geomagnetic reversal is not some atomic event but a gradual process lasting for several kY. Different parts of the Earth are in different stages of of the reversal, some further along than others. https://en.wikipedia.org/wiki/South_Atlantic_Anomaly

"Atomic" no, but there is evidence it isn't kY either. The article I linked was one of many that discussed the implications of the paper "Extremely rapid directional change during Matuyama-Brunhes geomagnetic polarity reversal" [1] published in 2014. In that paper, the authors studied different Lava flows that suggested a reversal can happen in a single human lifetime, with a change as rapid as 6 degrees per day.

I believe that a polarity change in fewer than 100 generations would be challenging for most species that see or use the magnetic field to adapt.

[1] https://academic.oup.com/gji/article/199/2/1110/618671

Is there practical expirementsl evidence demonstrating birds can sense magnetic fields? That is, can you train a bird to select between two boxes, one of which contains a strong magnet?

Just wondering. I'd read about theories regarding iron in the beaks and whatnot. Sounds cruel, but why not (a) train the bird to select the magnet, then (b) remove beak and check if it can still do the trick, or (c) remove eyes and see if it can still do the trick.

I'm not entirely sure, though, that (a) has been accomplished. Can't find anything on it.

> "Sounds cruel, but why not (a) train the bird to select the magnet, then (b) remove beak and check if it can still do the trick, or (c) remove eyes and see if it can still do the trick."

It sounds cruel because it is cruel.

Reminds me of this quote from Dostoevsky's "The Brothers Karamazov"[0]:

Tell me yourself, I challenge your answer. Imagine that you are creating a fabric of human destiny with the object of making men happy in the end, giving them peace and rest at last, but that it was essential and inevitable to torture to death only one tiny creature ... and to found that edifice on its unavenged tears, would you consent to be the architect on those conditions? Tell me, and tell the truth.

[0] http://www.bluffton.edu/homepages/facstaff/bergerd/classes/L...

Nice bit of literature reference there. The interesting thing about moral frameworks is there are so many to choose from.

Throughout history we have been known to send our sons and daughters to die in large numbers to first gain, and then protect, basic freedoms. And for other, less honourable, reasons as well...

Returning back to science, a utilitarian could easily make the case that, if it is impossible to avoid, being cruel to bird for the sake of humanity may be a tradeoff worth making.

So does morality/ethics boil down to numbers/metrics? I'm not being sarcastic; I don't know the answer myself ... and I'm not entirely sure that I would want to "know".

Humans have gained great powers of number calculation, but I suspect that our greatest power and obsession has always been story-telling. We tell stories to each other and ourselves, and those stories form the basis of our ethics and morality.

Which is why I think utilitarianism always feels cold and unsatisfying; it doesn't play well as a story.

> So does morality/ethics boil down to numbers/metrics?

The field of ethics essentially considers how to build and analyse arguments. Ethics generally does not make decisions; and it's not a flowchart you can follow to get a yes/no answer, either. People often use the world "unethical" as-if it is a proper adjective, meanwhile it actually refers to themselves having concluded that the act/object is not ethical within their reasoning; it's not an actual property of an act or object.

Much like broad philosophy, it's a language for expressing thoughts. It doesn't think for you. Or, if you like, mathematics is a language for expressing some other thoughts. Mathematics doesn't solve problems for you, or prevents you from writing 3+1=5.

There is a distinction between Ethics and Morals. Morals are the things you value, like liberty and happiness. Ethics are decision-making systems that you configure with morals. They are designed to aid you in situations where two or more of your morals/values are in conflict.

Before talking about Utilitarianism, we first must talk about it's parent Consequentialism. The basics are this; Consequentialists state that the outcomes of an ethical decision should leave the outcome in a superior moral position. This is opposite of such systems like Kantian Virtue Ethics that state a more a priori value on the decision, even if the outcome is negatively affected. Honor might be a Virtue Ethic, since you would always act honorably even if the situation makes that a bad course of action.

Utilitarianism is a balance point between two Consequentialist children: Ethical Egoism and Ethical Altruism. Both (respectively) examine the outcome based on the individual making the decision, and the rest of the situation outside of the individual. Combining both Utilitarianists examine the outcomes of both the individual and the surrounding environment when determining which course of action to take.

tl;dr: Ethics are amoral systems of decision making that tell you where and how to apply your morals.

> Morals are the things you value, like liberty and happiness

I disagree, the conventional and I think the more widely understood meaning of 'morals' would be 'principles' or 'standards of right and wrong'. I think the term 'values' would do just fine.

Not sure why your comment was downvoted. Its an informed comment that adds to the discussion.

Any moral or ethical system will have logical inconsistencies and fallacies because they are based on instincts developed by human evolution, not mathematical axioms. Those instincts were developed in groups of 100-200 people, directly depending on your ability to see other human being face to face, know him and emphasize with them. They break down when you try to extrapolate them to millions of people.

"a utilitarian could easily make the case that"

Are you making that argument? Your comment seems an extreme example of writing that uses the passive voice.

I think it's more interesting to honestly discuss the argument and its merits if one doesn't have to personally vouch for it upfront.

The moral framework used generally tends to determine where one falls on the major debates in ethics. As I happen to be aware of the different moral frameworks, I do not have the luxury of being beholden to an unexamined, implicitly "chosen" moral framework. Often times my internal debate is which framework is the most appropriate to evaluate the ethical question at hand. I am talking about hard ethical problems here like euthanasia, not the everyday things like lying, theft, etc.

To answer your question, while in my personal life I take a more deontological (Kantian) moral approach, if I were in a policy making role I'd take the pragmatic, utilitarian road; that bird would be sacrificed if it really did help advance science. Ecce homo.

Yea, there are some interesting experiments on this stuff. Though they used drugs vs surgery to test it out.

Tunnel test

The pigeons were trained to go to one end of the tunnel if the coils were switched on, generating a magnetic field, and to the other if they were switched off, leaving Earth's natural field unperturbed. "I was pleasantly surprised. The pigeons were very fast learners," says Mora, now at the University of North Carolina in Chapel Hill.

Their skills were impaired, however, when the researchers attached magnets to their upper beaks, and also when the upper beak was anaesthetized. This suggests that their ability is down to the presence of magnetically sensitive material in this area, the researchers report in this week's Nature1."


Hey, thanks! That's what I was looking for! Their procedure is far less bloody than my proposal... that's probably why I'm not a biologist. I guess the "Let's just chop it off and see what happens" ploy isn't all that sophisticated.

maybe just blindfold the bird, instead of removing the eyes

Don't most bird just go to sleep when blindfolded ? Or is it just an idea that got in my mind ?

They don't tend to actually sleep. They do become more docile, because they can't see to fly without risking hitting something.

Thinking about it, it was pretty dumb on my part. I know about hunting birds, I should have thought about that.

> they can't see to fly without risking hitting something.

This sentence makes me wonder: are they docile because it genuinely calms them, or are they entering a sort of helpless automatic panic mode, like "OMFG no escape, can't fly, can't move"?

The latter sounds like the bird is getting a terrifying experience.

Alligators do. Not sure about birds

You are genius, coz I consider myself non violent, and even I couldn't think of the blindfold idea when the above guy spoke of removing their eyes

I considered blindfolding, but from what I gather the protein would be activated merely with the presence of the field.

Looks like the humane way to test, according to the article cited above, is to affix magnets to the eyes/beak to see if it disrupts anything. In any case, in retrospect, I personally feel my suggestion to remove the beak is more cruel than removing the eyes. Both are hideous to contemplate. But, a bird without a beak? That's just a miserable thing to imagine.

The original article suggests that the cryptochrome responsible for magnetic sensing must be stimulated by light to work, and in particular light of the right wavelength.

“One man's life or death were but a small price to pay for the acquirement of the knowledge which I sought, for the dominion I should acquire and transmit over the elemental foes of our race.”

- Mary Shelley’s Frankenstein

I would hope science has evolved were we could devise a test without having to resort to such a method. Maybe I am too far removed from such things, out of sight out of mind.

There are probably ways to accomplish what you are saying without mutilating the bird. i.e. Just cover its eyes instead of removing them. etc. etc.

next remove the guts and feathers; add salt, pepper, flour, egg whites; dip in hot oil; enjoy

I wonder if the Earths magnetic field flipping every half a Million years affects birds untowardly? Or have they evolved to deal with it?

A totally uneducated guess is that they will automatically handle the transition. In experiments with humans wearing glasses to vertically flip their visuals they start to see the flipped view as normal after a few days. No doubt birds would be the same. There’s also the evidence that birds have not gone extinct

If the images in the article are accurate, the birds don't really see the polarity of the field, merely the alignment, so they don't really see "north", "east", "south" and "west", merely "latitudinal" or "longitudinal".

They would probably combine with sunlight to get the real orientation – an approach which would continue to work with a flipped magnetic field.

If you have 3D polarized glasses from the cinema you can go outside on a sunny day see this alignment in the sky. It's really cool, highly recommended.

You can see it with the naked eye, too, near the center of your vision.


lots of subpopulations of many migratory birds dont infact migrate, or migrate very short distances. May play a role in their recovery.

I'm not an expert in this domain, but my guess is that a flip of the eaths magnetic field is not instantaneous, but it takes over a few bird generations.

I think it would be hard to evolve to protect against something that only happens every half million years. We're probably going to need to observe the behavioral changes the next time it happens to have any clue.

If you liked this story, I recommend you "Life on the Edge: The Coming of Age of Quantum Biology".


This is really hard to understand in terms of how the eye works. Conventional sight works by detecting photons hitting the retina. But "seeing" a magnetic field seems like it would only work when the eye is literally inside of the field. Magnetic fields don't project or reflect off of things, they are where they are. The eye would have to be directly affected by the field to see it.

And then they wouldnt be able to see parts of the field they are not currently in. Magnetic fields don't radiate anything, they ARE the radiation. It's like trying to see a laser that is not pointed at your eye. It's there, but it cant be detected because no photons from it are hitting your eye.

you can see a laser that is not pointed at your eyes. Use fog.

The atmosphere is known to diffuse the vectors of electromagnetic radiation. That’s how we get blue skies and red sunsets. Who says it’s not having the same effect on earth’s magnetic fields

You are kind of proving my point though. With fog, you can see the laser because photons are bouncing off the fog and hitting your eye. This article isn't saying that photons are bouncing the magnetic fields and then hitting their eyes, they are saying the eyes can literally detect magnetic fields. If the birds were seeing magnetic fields via how they interact with photons, then everyone would be able to 'see' magnetic fields because we can all see photons. This is saying that the magnetic fields are directly visible by birds.

I’m aware that photons have to physically interface with the retina to be seen. You’re missing my point. Earth’s atmosphere acts like the fog as a laser travels through it — it diffuses the vectors, making them visible to an observer not along the path from the light source. When you look up at the clear sky during the day you don’t see the sun and then pure black space (and stars).

Likewise the effects of the magnetic field interface with earth’s atmosphere.

For example Earth's magnetic field deflects solar wind. The solar wind interacting with the magnetic field transfers some of its energy into earth’s atmosphere.

You eye is literally in the earths magnetic field. That said I'm also having a job figuring how the mechanism would work.

Could someone please explain the physics in respect of how blue light and magnetic fields measurably interact with this protein?

It's actually linked in the article, this explains more about the working theory they have https://physicsworld.com/a/birds-measure-magnetic-fields-usi...

title was not click bait. they can actually see it. nice. can't wait for the bodymod crowd to catch up on that one

They've already managed to use CRISPR to give color blind primates their full vision back...


Reminds me of some filler-dialogue from the game Deus Ex (2000), where a late-working employee in the building you need to infiltrate is complaining:

> This chemoreceptor patent-proposal is kicking my ass. Hundley won't let me down until it's done. Hardly worth filing for, in my opinion. Who wants to smell the difference between xenon and radon?

the mechanism has to do with chromatin and quantum entanglement in the bands that connect the rods (cones?) in their retinas. don't think the bodymod crew is going to catch up to this any time soon... AR will get there first for sure.

> Whoa, evolution. Just... whoa.

At some point this really starts to sound ridiculous.

What is it like to see a magneric field?

Because it's in their eyes, it would have a visual interpretation. And some evolutionary advantage to that visual advantage, else the cells could be anywhere (unless there's a biochemical similarity to cones?)

However, a field isn't like photons hitting the retina. It would probably be a new colour, which we can't imagine, but I'm asking where that colour would appear, to indicate the field.

Perhaps a faint fog, varying in strength with direction - like the sky at dusk and dawn.

There are some speculative illustrations at the bottom of the article.

If you have 3D polarized glasses from the cinema you can go outside on a sunny day see this alignment in the sky. It's really cool, highly recommended

That's not a magnetic field, that's polarisation of the light in the sky due to scattering.

Slightly off topic, but I am so thankful for firefox's reader. The amount of annoying ads blinking/flashing is enough to drive me up a wall

You should try Firefox's tracking protection. This was actually one page I didn't use reader view for!

Can anyone explain in layperson terms how this is different from regular old polarization?

Light travels from one point to another in a direction.

Perpendicular to that direction light "wiggles" on it's way from origin to destination.

The direction of the 'wiggle' is the polarization of the light.

Unpolarized light wiggles in every direction while polarized light only wiggles in one.

Certain things (like how the sun shines on the sky) creates polarized light naturally.

The earth's magnetic field DOES NOT polarize light.

Birds have a protein in their eyes that uses blue light + the earths magnetic field to visualize the magnetic field around them.

Similar to visualizing the polarity of light, we lack the ability to visualize magnetic fields, making both foreign concepts.

Are you referring to animals (including, under the right conditions, humans) seeing the polarization of light?

That allows them to figure out the position of the Sun when it is not visible due to clouds, which is indeed useful for navigating.

But what this article is about is seeing the Earth's magnetic field.

At least some migratory birds are able to detect both their longitude and latitude [1] [2], which requires more than just knowing where the Sun is.

Humans have been able to figure out latitude for a very long time...at least as far back as the ancient Greeks, and probably much farther back.

Longitude, on the other hand, eluded us until we were able to make reasonably accurate clocks. For sea navigation, that wasn't until the 18th century, long after we had compasses and knew about polarized light.

[1] http://www.cell.com/current-biology/abstract/S0960-9822(17)3...

[2] https://www.uni-oldenburg.de/en/news-single/art/how-migrator...

I've heard people can too if they look at the sky under the right conditions.

https://en.wikipedia.org/wiki/Haidinger%27s_brush is a real and really cool phenomenon, but it detects light polarization, not magnetic orientation.

Does the polarization of the light in sky correspond with the poles of the earth? If so, since the effect has direction, wouldnt you have a compass in the sky?

I was just able to see the effect for the first time using this image [1] full screen on my phone :) Brightness up, screen rotation off, hold out the phone and turn it like your steering a car. Jumped right out at me. It's always at the center of my vision, so if I look around the screen as I'm turning, it follows. The yellow always points to the longer edges of my phone. It's hard to hold it in view when not turning though.

[1] http://www.solidbackgrounds.com/images/2560x1600/2560x1600-v...

Looks like the polarization in the sky coresponds to the sun, not the poles. https://mysite.du.edu/~jcalvert/optics/haiding.htm

So couple this with evolution and you have migration, no?

Probably migration existed first, but those with the ability to see the magnetic field were much more successful at migrating, probably due to expending less energy during.

If birds can figure out how to have blockchain based browsers embedded in their eyes to help with navigation, why can't we just copy that tech for our own uses?

Can we do an Initial Cryptochrome Offering?

I would love to add this ability.

Flagging for a title change, perhaps:

"Birds can see Earth's magnetic fields due to protein in their eyes"

or the original, more clickbait-y title:

"Birds Can See Earth's Magnetic Fields, And We Finally Know How That's Possible"

Seems to me the first part of the title makes a reasonable whole title, so let's go with that for now.

Also, we changed the URL from http://archive.is/SlcSL. archive.is is an excellent site for archiving, but not for HN submitting, because it's important for readers to see the actual domain. For the same reason, we don't allow link shorteners.

The eye link to magnetic field navigation has been known for years; the mechanism has not been.

Ok, we've put some cryptochromes in the title.

Cryptochromes? Will there be an ICO?

Crypto birds? I'm in

Cryptoc.. what? Crypto?! Sir when ICO?

Is it bad that I first thought of the electric scooter company Bird?

If the cryptocrome mechanism is real, that's pretty spectacular. I thought that the idea of magnetoreception was mostly abandoned in favor of visual navigation, but I was wrong.

Cryptochromes? That sounds like Google launched a cryptocurrency. These birds are mining Cryptocurrency using Magnetic fields. LOL!

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