Some Birds Can See Magnetic Fields

jamie found a post on the Not Exactly Rocket Science blog on research indicating that some birds can literally see magnetic fields, but only if the vision in their right eye is sharp (abstract at Current Biology). "The magnetic sense of birds was first discovered in robins in 1968, and its details have been teased out ever since. Years of careful research have told us that the ability depends on light and particularly on the right eye and the left half of the brain. The details still aren’t quite clear but, for now, the most likely explanation involves a molecule called cryptochrome. Cryptochrome is found in the light-sensitive cells of a bird’s retina and scientists think that it affects just how sensitive those cells are. ... The upshot is that magnetic fields put up a filter of light or dark patches over what a bird normally sees. These patches change as the bird turns and tilts its head, providing it with a visual compass made out of contrasting shades."

Comments

augmented reality

[Superken7]

augmented reality at its best.

Makes me think what other "natural augmented reality senses" are possible, or even already exist in other species.

Re:augmented reality

[fuzzyfuzzyfungus]

Given that the number of things that you can sense without breaking the known laws of physics is limited, we have reasonably informed basis for speculation, plus a lot of field data:

Electromagnetic radiation: everything from pretty longwave IR to UV is well documented(IR in certain snake's heat-sensor pits, UV in some insects, "visible light" is obvious enough) There are certain radiotrophic fungi, which can perform a process analogous to photosynthesis; but with gamma radiation. This isn't a directly sensory function; but it does imply that there is a biologically produce-able molecule, in the wild, that could serve as the basis of a gamma-ray vision system(if not, perhaps, a very fast one) The unknown(at least for me) is radio waves. I've never heard of anything using them; but organisms with conductive structures linked to their nervous systems are potential suspects....

Magnetic fields: Confirmed in birds and some insects; both as a 'compass-like' directional sense, and as a visual signal. And, since electricity and magnetism are related, anything with reasonably high-resolution magnetic sensors can detect electrical currents, as well.

Sound waves: Confirmed, obviously enough, across a pretty wide frequency band in all sorts of species, both as a conventional 'hearing' sense, and for detection and ranging.

Chemicals: Anything with a sense of smell is a pretty sensitive chemical detector, some better than others. Even bacteria can follow chemical gradients, and animals with sophisticated olfactory systems can detect tens or hundred of thousands of chemicals, and at fairly low concentrations...

Electrical currents: Sharks, possibly among others, can sense the electrical impulses that make your muscles move at distances long enough to make this a useful hunting tool. Don't know if anyone else has picked up this trick...

Can anyone think of other physical phenomena that may or may not have biological sensors capable of detecting it, and any known cases?

Tech version?

[x_IamSpartacus_x]

I'd love to see a Tech version of this. I may be completely ignorant and it may already exist but it seems like, since we now know the science of how to see magnetic fields, we could develop an artificial "eye" so to speak, that could do this. It would be neat to look at power lines or just browse the city and see the magnetic fields cast off by different infrastructure.

Re:Why haven't we evolved to see IR or microwave?

[RivenAleem]

Why would you need night vision if you are able to survive the day?

Animals with great night vision tend to have it because it is not safe for them to be out and about during the day when the majority of predators are up and about. Consequently a number of predators themselves developed night vision (they didn't develop it, just that predators with night vision were able to find a niche, see below). I'm assuming you mean to ask why humans didn't evolve the abilities, the answer is simple: we are well capable of being active throughout the day, and decide instead to rest at night.

Even though it is possible to push a human's visible spectrum into the IR range, with a long treatment of Vitamin A (http://www.edkeyes.org/blog/050825.html), there is no point in doing so, as it's not needed as a survival tool.

The same goes for microwave radio. We do not need it to be superior to all other animals on the planet, so there has never been a reason for why it would develop.

You have to remember that evolution is the process whereby an animal mutates randomly and a trait appears, if that animal survives to reproduce (not killed off by something) then that trait is passed on to a new generation. If that mutation proves negative to survival, chances are the animal dies and does not get to pass on that trait to next generation.

You can't simply expect a need for night vision to present itself, and in response the body evolves in order to comply with that need.

Re:Why haven't we evolved to see IR or microwave?

[mister_playboy]

Specifically, females with a 4th set of cones.

Spy vs Spy

[westlake]

Some humans seem to be able to see a little further into UV, but nothing like chickens or certain insects.

In WWII the OSS recruited elderly volunteers with cataracts who could see into the UV range. They were posted as coast watchers for communication with submarines and landing parties.

One of the best reads around for the real world of spy tech is Stanley Lovell's Of Spies and Stratagems. Lovell was the OSS "Moriarty" - a later generation would see him "Q," and no less an enthusiastic, inventive and deadly prankster.

OK, I should probably call Randi

[IndustrialComplex]

As a child, I found that if I were to walk under/near certain transformers, I started to see black waves at the very edge of my vision. I couldn't really describe it as they tended to be fairly quick, and explaining to somone just what waves of black at the edge of your vision would look like was/is difficult.

I grew up near a steel mill, and their furnaces were electric, and on a hill near where I lived there was this MASSIVE collection of electrical equipment (Transformers, relays, etc). If I were to walk along the outer perimiter of this area, I would see those waves again.

I've noticed this my entire life, and it happens rarely, but is always associated with electrical equipment. I also got the same 'waves' when I accidentally grabbed a makeshift fishing worm extractor (essentially an AC cord attached to a long metal rod you stick in the ground) I DEFINITELY saw the waves in my vision then (and nearly was electrocuted).

Now, is this something that other people have in the presence of very large em fields? Or did I stick a nail up my nose when I was a toddler and forgot about it?

It's not magic in any case, so I don't think I could go for Randi's offer right?

Re:OK, I should probably call Randi

[IndustrialComplex]

So it does not surprise me at all to hear that some people can see E&M fields

I also don't want to come across as delusional, and I don't really see EM fields like a lot of people claim. It's just that when I was younger, and (confirmation bias maybe) in the presence of transformers. I saw a slight wavy blackness at the edge of my vision.

It's possible that more people get this all the time, and just don't notice it. It is very slight, and very transient. The transformer I walked past to check it out was also later determined to be malfunctioning (it began arcing electricity a year later).

It could be a completely benign aspect as well, and thus not really influenced by evolutionary pressures. I'm sure that until the 20th century, the chances of someone being exposed to a strong EM field were pretty low (Excepting thunderstorms perhaps), and since getting struck by lightning often has other warning signs (Like a giant ass thundercloud), being able to slightly see/feel the EM field isn't that advantageous.

For all I know, I could have just ingested too much iron as a kid and a strong field messes with something in my retina.

I don't even know if my vision is still good enough to produce the effect again. I think I am going to go take a walk past some places where I remember it happened and see if it occurs again. If it does, I'll definately contact Randi.

I'd have to think of some test conditions too. Maybe a bright room with no variation in the lighting or colors. Incandescent bulbs or sunlight would be nice for producing light with no extra EM fields. Some sort of wall housing the equipment to produce a field that I can't see. A computer randomly generating a control signal for the equipment. Maybe give me a dial that I can turn to indicate how strong the waves I'm seeing are.

Heh, as a test engineer, this could be fun.