How do animals & bacteria sense compass direction?

In summary, migratory birds possess a unique biochemistry that incorporates magnetite, a ferromagnetic material, within their bodies. This allows them to utilize their orientation and sense magnetic polar direction, governing their spatial movement. Other examples of this behavior can be seen in various animals such as honey bees, homing pigeons, sharks, dolphins, and bacteria. Researchers have found stable needle-like strands of magnetite crystal in these animals, serving as receptors that send directional information to the brain. This ability has been extensively studied in birds, particularly the bobolink, which carries a compass made of magnetite in its head.
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Ouabache
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You are probably aware of migratory behavior of birds. But what is the mechanism that accounts for this?

It is based on a unique biochemistry that incorporates ferromagnetic material (magnetite) within them and utilizes their orientation to govern its spatial movement (horizontal and vertical). Outside of migration behavior, other examples of orientation behavior due to magnetite, occur across the animal kingdom: honey bees, homing pigeons, sharks, dolphins, newt, rainbow trout, salmon. Even certain bacteria e.g. Magnetospirillum gryphiswaldense exhibit this. Researchers found stable needle-like strands of magnetite crystal (magnetic dipoles) in these bacteria.
 
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here is an interesting article that addresses "Navigating With A Built-In Compass":
http://www.nwf.org/nationalwildlife/article.cfm?articleId=682&issueId=26
 
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gerben said:
here is an interesting article that addresses "Navigating With A Built-In Compass":
http://www.nwf.org/nationalwildlife/article.cfm?articleId=682&issueId=26
Nice one gerben! The bobolinks (and a few other species) sure have evolved quite an impressive mechanism for direction finding :biggrin:

So the hundred dollar question is, how does the magnetite interface with the brain, so that it senses magnetic polar direction? Does the brain compare magnetic field to a spatial map comprised of brain cells? :uhh:

Do we have any neuroethologists here on PF?

Quote from gerben's http://www.nwf.org/nationalwildlife/article.cfm?articleId=682&issueId=26:
"Like any good pilot, the bobolink carries a compass. Recent research suggests that cells in the bird's head contain magnetite, an iron oxide crystal that aligns with magnetic north like a tiny compass needle. Scientists think these cells may serve as receptors that send directional information to the brain. Many other animals apparently also have such cells: Magnetite has been found in the heads of migratory fish, sea turtles and humpback whales. Of all the wildlife navigators, birds so far are the best studied."
 
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What is the role of magnetism in animal and bacterial navigation?

Magnetism plays a crucial role in animal and bacterial navigation as it serves as a compass to sense direction. It is believed that animals and bacteria have specialized cells called magnetoreceptors that are sensitive to magnetic fields. These magnetoreceptors help them detect the Earth's magnetic field and use it to orient themselves in a particular direction.

How do animals and bacteria detect the Earth's magnetic field?

Animals and bacteria have various methods of detecting the Earth's magnetic field. Some animals, such as birds and sea turtles, have specialized organs called magnetite-based receptors that act as tiny compass needles. Bacteria, on the other hand, use a protein called magnetosome which acts as a tiny magnet, helping them align with the Earth's magnetic field.

Can animals and bacteria sense both the direction and strength of the Earth's magnetic field?

Yes, animals and bacteria are capable of sensing both the direction and strength of the Earth's magnetic field. Some animals, like birds, can even detect small changes in the magnetic field, allowing them to navigate over long distances. Bacteria also have the ability to sense the intensity of the magnetic field, which helps them orient themselves in different environments.

Do all animals and bacteria have the ability to sense magnetic fields?

No, not all animals and bacteria have the ability to sense magnetic fields. The ability to sense magnetic fields is typically found in migratory animals and bacteria living in aquatic environments. However, recent studies have shown that some land-based animals, such as foxes and cattle, also possess this ability.

How do scientists study the mechanisms of animal and bacterial navigation?

Scientists use various techniques to study how animals and bacteria sense compass direction. These include behavioral experiments, genetic studies, and neuroimaging techniques. By manipulating the magnetic fields and observing the behavior of animals and bacteria, scientists can gain a better understanding of the mechanisms behind their navigation abilities.

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