How do animals & bacteria sense compass direction?

AI Thread Summary
The discussion centers on the migratory behavior of birds and the underlying mechanisms that facilitate this phenomenon. Key to this navigation is the presence of magnetite, a ferromagnetic material, which allows birds and various other animals, including honey bees, homing pigeons, sharks, and certain bacteria, to orient themselves using Earth's magnetic field. Research indicates that magnetite crystals in specific cells, particularly in birds, may act as receptors that transmit directional information to the brain. This raises questions about how the brain processes this magnetic data, potentially comparing it to a spatial map. The bobolink is highlighted as an example of a bird with an evolved mechanism for direction finding, underscoring the complexity of animal navigation systems.
Ouabache
Science Advisor
Homework Helper
Messages
1,345
Reaction score
8
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.
 
Last edited:
Biology news on Phys.org
here is an interesting article that addresses "Navigating With A Built-In Compass":
http://www.nwf.org/nationalwildlife/article.cfm?articleId=682&issueId=26
 
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? :rolleyes:

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."
 
Last edited:

Thread 'Chagas disease now established in US'

Chagas disease, long considered only a threat abroad, is established in California and the Southern U.S. According to articles in the Los Angeles Times, "Chagas disease, long considered only a threat abroad, is established in California and the Southern U.S.", and "Kissing bugs bring deadly disease to California". LA Times requires a subscription. Related article -...
View full post »

Thread 'I need help understanding this quote about recent Natural Selection'

I am reading Nicholas Wade's book A Troublesome Inheritance. Please let's not make this thread a critique about the merits or demerits of the book. This thread is my attempt to understanding the evidence that Natural Selection in the human genome was recent and regional. On Page 103 of A Troublesome Inheritance, Wade writes the following: "The regional nature of selection was first made evident in a genomewide scan undertaken by Jonathan Pritchard, a population geneticist at the...
View full post »

Hot Threads

Recent Insights

Back
Top